CTB-SAP References

CTB-SAP (Cat. #IT-14)

85 entries found for : it-14

Impact of limb phenotype on tongue denervation atrophy, dysphagia penetrance, and survival time in a mouse model of ALS

Mueller M, Thompson R, Osman KL, Andel E, DeJonge CA, Kington S, Stephenson Z, Hamad A, Bunyak F, Nichols NL, Lever TE (2022) Impact of limb phenotype on tongue denervation atrophy, dysphagia penetrance, and survival time in a mouse model of ALS. Dysphagia doi: 10.1007/s00455-022-10442-4

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A spinal microglia population involved in remitting and relapsing neuropathic pain

Kohno K, Shirasaka R, Yoshihara K, Mikuriya S, Tanaka K, Takanami K, Inoue K, Sakamoto H, Ohkawa Y, Masuda T, Tsuda M (2022) A spinal microglia population involved in remitting and relapsing neuropathic pain. Science 376(6588):86-90. doi: 10.1126/science.abf6805

Objective: To investigate pain recovery mechanisms.

Summary: The authors reveal a mechanism for the remission and recurrence ofneuropathic pain, providing potential targets for therapeutic strategies.

Usage: The dose of CTB-SAP and IB4-SAP was 8 ug/10 uL, diluted in PBS.

Related Products: CTB-SAP (Cat. #IT-14), IB4-SAP (Cat. #IT-10)

Divergent receptor utilization is necessary for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections

Borkowski LF, Smith CL, Keilholz AN, Nichols NL (2021) Divergent receptor utilization is necessary for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections. J Neurophysiol 126(3):709-722. doi: 10.1152/jn.00236.2021

Objective: The authors tested the hypothesis that phrenic long-term facilitation (pLTF) following treatment with CTB-SAP is: 1) adenosine 2A (A2A) receptor-dependent at 7d; and 2) serotonin (5-HT) receptor-dependent at 28d.

Summary: This study furthers understanding of the contribution of differential receptor activation to pLTF and its implications for breathing following respiratory motor neuron death.

Usage: Male rats received bilateral, intrapleural injections of CTB-SAP or Saporin Control (25 μg).

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

How are adenosine and adenosine A2A receptors involved in the pathophysiology of amyotrophic lateral sclerosis?

Mori A, Cross B, Uchida S, Kerrick Walker J, Ristuccia R (2021) How are adenosine and adenosine A2A receptors involved in the pathophysiology of amyotrophic lateral sclerosis?. Biomedicines 9(8):1027. doi: 10.3390/biomedicines9081027

Objective: To examine potential biomarkers and the acute symptomatic pharmacology, including respiratory motor neuron control, of adenosine A2A receptor antagonism, and to explore the potential of the A2A receptor as a target for Amyotrophic Lateral Sclerosis (ALS) therapy.

Summary: CTB-SAP is listed in a table of experimental animal models of ALS. Intrapleural CTB-SAP injected rats (neurotoxic model of respiratory motor neuron death).

See: Seven YB et al. Adenosine 2A receptor inhibition protects phrenic motor neurons from cell death induced by protein synthesis inhibition. Exp Neurol 323:113067, 2020.

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Clobetasol promotes neuromuscular plasticity in mice after motoneuronal loss via sonic hedgehog signaling, immunomodulation and metabolic rebalancing

Vicario N, Spitale FM, Tibullo D, Giallongo C, Amorini AM, Scandura G, Spoto G, Saab MW, D'Aprile S, Alberghina C, Mangione R, Bernstock JD, Botta C, Gulisano M, Buratti E, Leanza G, Zorec R, Vecchio M, Di Rosa M, Li Volti G, Lazzarino G, Parenti R, Gulino R (2021) Clobetasol promotes neuromuscular plasticity in mice after motoneuronal loss via sonic hedgehog signaling, immunomodulation and metabolic rebalancing. Cell Death Dis 12(7):625. doi: 10.1038/s41419-021-03907-1

Summary: The focal removal of confined populations of spinal MNs by injection of CTB-SAP has proven to be useful in mimicking respiratory dysfunction, dysphagia, and focal MN loss.

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Utilization of pectoralis minor accessory inspiratory muscles in a rodent model of respiratory motor neuron loss

Borkowski L, Nichols N (2021) Utilization of pectoralis minor accessory inspiratory muscles in a rodent model of respiratory motor neuron loss. The FASEB Journal 35 (S1). doi: 10.1096/fasebj.2021.35.S1.01843

Objective: To develop a model of selective respiratory motor neuron death to study how breathing is impacted and advance targeted therapeutic interventions.

Summary: Prior to ventilatory failure, patients can maintain breathing potentially via recruitment of accessory inspiratory muscles (e.g., pectoralis minor). The data suggest that the pectoralis minor muscles have an independent motor pool that can become recruited to assist in maintaining eupnea (normal respiration).

Usage: Adult male rats received bilateral CTB-SAP or control (CTB unconjugated to SAP) intrapleurally.

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A systematic review of oropharyngeal dysphagia models in rodents

Kim HN, Kim JY (2021) A systematic review of oropharyngeal dysphagia models in rodents. Int J Environ Res Public Health 18(9):4987. doi: 10.3390/ijerph18094987

Objective: To organize the rodent models of oropharyngeal dysphagia reported to date.

Summary: Applying and analyzing the treatment in rodent models of dysphagia induced from various causes is an essential process to develop symptom-specific treatments. The results of this study provide fundamental and important data for selecting appropriate animal models to study dysphagia.

Usage: CTB-SAP treated rats exhibited targeted hypoglossal motor neuron death; decreased hypoglossal motor output; and swallowing and lick deficits.

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CSF-CN contributes to cancer-induced bone pain via the MKP-1-mediated MAPK pathway

Chen P, Pan M, Lin QS, Lin XZ, Lin Z (2021) CSF-CN contributes to cancer-induced bone pain via the MKP-1-mediated MAPK pathway. Biochem Biophys Res Commun 547:36-43. doi: 10.1016/j.bbrc.2021.02.010

Summary: Cerebrospinal fluid-contacting nucleus (CSF–CN) has been reported to be involved in the development of neuropathic pain and inflammatory pain. This study aimed to see whether it also has a role in cancer-induced bone pain (CIBP). Targeted ablation of CSF-CN dramatically aggravated pain sensitivity.

Usage: Injection via icv of CTB-SAP was performed to “knockout” the CSF-CN.

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Tongue and hypoglossal morphology after intralingual cholera toxin B-saporin injection

Lind LA, Lever TE, Nichols NL (2021) Tongue and hypoglossal morphology after intralingual cholera toxin B-saporin injection. Muscle Nerve 63(3):413-420. doi: 10.1002/mus.27131

Objective: To evaluate tongue morphology and ultrastructural changes in hypoglossal neurons and nerve fibers in an inducible rat model of dysphagia.

Summary: Preliminary results indicate this model may have translational application to a variety of neurodegenerative diseases resulting in tongue dysfunction and associated dysphagia.

Usage: Rats assigned to the CTB-SAP group (n = 10) received 25 μg CTB-SAP to produce hypoglossal motor neuron death.

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Exercise is neuroprotective on the morphology of somatic motoneurons following the death of neighboring motoneurons via androgen action at the target muscle

Chew C, Sengelaub DR (2021) Exercise is neuroprotective on the morphology of somatic motoneurons following the death of neighboring motoneurons via androgen action at the target muscle. Dev Neurobiol 81(1):22-35. doi: 10.1002/dneu.22794

Objective: To determine where the necessary site of androgen action is for exercise-driven neuroprotective effects on induced dendritic atrophy.

Summary: Exercise following neural injury exerts a protective effect on motoneuron dendrites, which acts via androgen receptor action at the target muscle.

Usage: Motoneurons innervating the left vastus medialis (VM) muscle were selectively killed by intramuscular injection of cholera toxin-conjugated saporin (CTB-SAP).

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Differential mechanisms are required for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections.

Borkowski LF, Nichols NL (2020) Differential mechanisms are required for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections. Exp Neurol 334:113460. doi: 10.1016/j.expneurol.2020.113460

Objective: To understand the mechanism responsible for this difference in magnitude of phrenic long-term facilitation (pLTF)

Summary: pLTF in 7d CTB-SAP treated rats is elicited primarily through TrkB and PI3K/Akt-dependent mechanisms, whereas BDNF and MEK/ERK-dependent mechanisms induce pLTF in 28d CTB-SAP treated rats.

Usage: Rats received bilateral intrapleural injections of CTB-SAP; 25 μg dissolved in PBS.

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Exercise is neuroprotective to motoneuron dendrites following partial motoneuron depletion via a mechanism dependent on androgen receptors at the target muscle

Chew C (2020) Exercise is neuroprotective to motoneuron dendrites following partial motoneuron depletion via a mechanism dependent on androgen receptors at the target muscle. Indiana Univ, Dept Psychol & Brain Sci Thesis.

See: Chew C et al. Exercise promotes recovery after motoneuron injury via hormonal mechanisms. Neural Regen Res 15(8):1373-1376, 2020.

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Respiratory pathology in the Optn-/- mouse model of Amyotrophic Lateral Sclerosis.

McCall AL, Dhindsa JS, Pucci LA, Kahn AF, Fusco AF, Biswas DD, Strickland LM, Tseng HC, ElMallah MK (2020) Respiratory pathology in the Optn-/- mouse model of Amyotrophic Lateral Sclerosis. Respir Physiol Neurobiol 282:103525. doi: 10.1016/j.resp.2020.103525

Summary: Tongue muscle weakness results in dysarthria and dysphagia leading to recurrent aspiration, choking, and aggravation of respiratory disease.

See: Lind LA et al. Hypoglossal Motor Neuron Death Via Intralingual CTB-saporin (CTB-SAP) Injections Mimic Aspects of Amyotrophic Lateral Sclerosis (ALS) Related to Dysphagia. Neuroscience 390:303-316, 2018.

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Local riluzole release from a thermosensitive hydrogel rescues injured motoneurons through nerve root stumps in a brachial plexus injury rat model

Fang J, Li L, Zhai H, Qin B, Quan D, Shi E, Zhu M, Yang J, Liu X, Gu L (2020) Local riluzole release from a thermosensitive hydrogel rescues injured motoneurons through nerve root stumps in a brachial plexus injury rat model. Neurochem Res 45(11):2800-2813. doi: 10.1007/s11064-020-03120-0

Summary: The authors refer to a review by Gulino describing two rodent models of motoneuron degeneration were induced by neurotoxics including volkensin and cholera toxin-B saporin, which are able to destroy motoneurons through retrograde transportation.

See: Gulino R Neuroplasticity and Repair in Rodent Neurotoxic Models of Spinal Motoneuron Disease. Neural Plast 2016:2769735, 2016.

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Exercise promotes recovery after motoneuron injury via hormonal mechanisms.

Chew C, Sengelaub DR (2020) Exercise promotes recovery after motoneuron injury via hormonal mechanisms. Neural Regen Res 15(8):1373-1376. doi: 10.4103/1673-5374.274323

Objective: To describe how exercise is neuroprotective for motoneurons, accelerating axon regeneration following axotomy and attenuating dendritic atrophy following the death of neighboring motoneurons.

Summary: Exercise offers a simple, low barrier-to-entry behavioral intervention which is neuroprotective and pro-regenerative following neural injury.

Usage: Motoneurons innervating the left vastus medialis muscle were selectively killed by intramuscular injection of CTB-SAP (2 μL, 0.1%).

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Adenosine 2A receptor inhibition protects phrenic motor neurons from cell death induced by protein synthesis inhibition.

Seven YB, Simon AK, Sajjadi E, Zwick A, Satriotomo I, Mitchell GS (2020) Adenosine 2A receptor inhibition protects phrenic motor neurons from cell death induced by protein synthesis inhibition. Exp Neurol 323:113067. doi: 10.1016/j.expneurol.2019.113067

Objective: To test the hypothesis that A2A receptor antagonism promotes phrenic motor neuron survival and preserves diaphragm function when faced with toxic, neurodegenerative insults that lead to phrenic motor neuron death.

Summary: The authors utilized a novel neurotoxic model of respiratory motor neuron death using intrapleural injections of CTB-SAP. A2A receptors contribute to neurotoxic phrenic motor neuron death, an effect mitigated by A2A receptor antagonism.

Usage: Intrapleural administration of CTB-SAP (25 μg per side) causes: 1) profound phrenic motor neuron death (~5% survival); 2) ~7-fold increase in phrenic motor neuron A2A receptor expression prior to cell death; and 3) diaphragm muscle paralysis (inactive in most rats; ~7% residual diaphragm EMG amplitude during room air breathing).

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Renal denervation for treating congenital long QT syndrome: Shortening the QT interval or modulating sympathetic tone?

Kiuchi MG, Chen S, Carnagarin R, Matthews VB, Schlaich MP (2019) Renal denervation for treating congenital long QT syndrome: Shortening the QT interval or modulating sympathetic tone?. Europace 21(11):1755-1756. doi: 10.1093/europace/euz251

Summary: Targeted ablation of cardiac sympathetic neurons (TACSN) through CTB-SAP injection in the left stellate ganglion (LSG), inhibited its activation, improved sympathetic remodelling, and restored cardiac autonomic balance.

See: Xiong L et al. Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction. Europace 20(12):2036-2044, 2018.

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Exercise is neuroprotective following partial motoneuron depletion via androgen action at the target muscle

Chew C, Sengelaub DR (2019) Exercise is neuroprotective following partial motoneuron depletion via androgen action at the target muscle. Neuroscience 2019 Abstracts 134.13. Society for Neuroscience, Chicago, IL.

Summary: We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy in remaining motoneurons. Furthermore, systemic treatment with supplemental androgens is neuroprotective, and dendritic atrophy following partial motoneuron depletion is attenuated. Blockade of the androgen receptor at the target muscle prevents the neuroprotective effects on motoneuron dendrites in rats treated with supplemental androgens. We have recently shown that exercise is also neuroprotective on motoneuron dendrites following partial motoneuron depletion, and circulating levels of androgens have previously been shown to increase following exercise. Together, these results suggest that exercise may be neuroprotective via androgen action at the muscle. In the present study, we examine whether blockade of androgen receptors at the target musculature would prevent the neuroprotective effects of exercise on dendrites following partial motoneuron depletion. Motoneurons innervating the vastus medialis muscle in adult male rats were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, some saporin-injected rats were given implants of the androgen receptor antagonist hydroxyflutamide, either directly at the quadriceps musculature or interscapularly as a systemic control. Following saporin injections, some animals were allowed free access to running wheels attached to their home cages. Four weeks later, motoneurons innervating the ipsilateral vastus lateralis muscle were labeled with cholera toxin-conjugated horseradish peroxidase, and dendritic arbors were reconstructed in three dimensions. Compared with untreated males, partial motoneuron depletion resulted in decreased dendritic length in remaining quadriceps motoneurons. Early data suggests that following partial motoneuron depletion, exercised males with androgen receptor blockade at the quadriceps show dendritic lengths that are significantly shorter than those of exercised males with no treatment, while dendritic lengths in exercised males with interscapular implants do not differ from those of exercised animals without implants. These findings suggest that exercise may be protective against dendritic atrophy via androgens binding at the target musculature.

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Neuroprotective effects of exercise on the morphology of somatic motoneurons following the death of neighboring motoneurons.

Chew C, Sengelaub DR (2019) Neuroprotective effects of exercise on the morphology of somatic motoneurons following the death of neighboring motoneurons. Neurorehabil Neural Repair 33(8):656-667. doi: 10.1177/1545968319860485

Objective: To explore whether exercise shows the same neuroprotective effect on induced dendritic atrophy as that seen with androgen treatment.

Summary: Exercise following neural injury exerts a protective effect on motoneuron dendrites comparable to that seen with exogenous androgen treatment.

Usage: Motoneurons innervating the left vastus medialis muscle were selectively killed by intramuscular injection of CTB-SAP (2 μL, 0.1%). Saporin injection reduced the weight of the vastus medialis muscle; exercise had no effect on muscle weight.

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A2A and 5‐HT receptors are differentially required for respiratory plasticity over the course of motor neuron loss in intrapleurally CTB-SAP treated rats.

Borkowski LF, Nichols NL (2019) A2A and 5‐HT receptors are differentially required for respiratory plasticity over the course of motor neuron loss in intrapleurally CTB-SAP treated rats. FASEB J 33(1):843.3. Experimental Biology 2019 Meeting Abstracts doi: 10.1096/fasebj.2019.33.1_supplement.843.3

Objective: To investigate the role of serotonin (5-HT) and adenosine 2A (A2A) receptors in respiratory plasticity.

Summary: A2A receptors are necessary for respiratory plasticity early (7d), but 5-HT receptors are required late (28d).

Usage: Bilateral, intrapleural injections of: 1) CTB-SAP (25 μg), or 2) un-conjugated CTB and SAP (control) in rats.

Related Products: CTB-SAP (Cat. #IT-14)

Neuromuscular plasticity in a mouse neurotoxic model of spinal motoneuronal loss.

Gulino R, Vicario N, Giunta MAS, Spoto G, Calabrese G, Vecchio M, Gulisano M, Leanza G, Parenti R (2019) Neuromuscular plasticity in a mouse neurotoxic model of spinal motoneuronal loss. Int J Mol Sci 20(6):1500. doi: 10.3390/ijms20061500

Objective: To use a neurotoxic model of spinal motoneuron depletion, induced by injection of CTB-SAP, to investigate the possible occurrence of compensatory changes in both the muscle and spinal cord.

Summary: Plastic changes in surviving motoneurons produce a functional restoration probably similar to the compensatory changes occurring in disease. These changes could be driven by glutamatergic signaling; astrocytes contacting surviving motoneurons may support this process.

Usage: Mice received 2 injections of CTB-SAP (3 mcg CTB-Sap in 2 mcL PBS) into the medial and lateral left gastrocnemius muscle.

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Neuroprotective effects on the morphology of somatic motoneurons following the death of neighboring motoneurons: A role for microglia

Chew C, Kiley B, Sengelaub D (2019) Neuroprotective effects on the morphology of somatic motoneurons following the death of neighboring motoneurons: A role for microglia. Dev Neurobiol 79:131-154. doi: 10.1002/dneu.22652 Related Products: CTB-SAP (Cat. #IT-14)

Mechanisms of compensatory plasticity for respiratory motor neuron death.

Seven YB, Mitchell GS (2019) Mechanisms of compensatory plasticity for respiratory motor neuron death. Respir Physiol Neurobiol 265:32-39. doi: 10.1016/j.resp.2019.01.001

Summary: Discusses recent advances in understanding of mechanisms giving rise to compensatory respiratory plasticity in response to respiratory motor neuron death.

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Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction.

Xiong L, Liu Y, Zhou M, Wang G, Quan D, Shen C, Shuai W, Kong B, Huang C, Huang H (2018) Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction. Europace 20(12):2036-2044. doi: 10.1093/europace/euy090

Objective: To evaluate the cardiac electrophysiologic effects of targeted ablation of cardiac sympathetic neurons (TACSN) in a canine model of chronic myocardial infarction (MI).

Summary: Targeted ablation of cardiac sympathetic neuron attenuates sympathetic remodelling and improves ventricular electrical remodelling in the chronic phase of MI. These data suggest that TACSN may be a novel approach to treating ventricular arrhythmias.

Usage: 20 μl of CTB-SAP (1.2 mg/ml) was mixed with 4 μl of 3% Evans blue dye to make it visible (CTB-SAP is colorless), ensuring localization within the ganglia. The CTB-SAP/ Evan blue dye solution was slowly and intermittently injected into the left stellate ganglia using a glass micropipette.

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Targeted ablation of distal cerebrospinal fluid-contacting nucleus alleviates renal fibrosis in chronic kidney disease.

Qiu M, Li J, Tan L, Zhang M, Zhou G, Zeng T, Li A (2018) Targeted ablation of distal cerebrospinal fluid-contacting nucleus alleviates renal fibrosis in chronic kidney disease. Front Physiol 9:1640. doi: 10.3389/fphys.2018.01640

Objective: To test the hypothesis that distal cerebrospinal fluid-contacting nucleus (dCSF-CNs) might affect the renin-angiotensin system (RAS) in kidney injury progression.

Summary: Less CTB-labeled neurons were found in dCSF-CNs of CTB-SAP-treated rats. Meanwhile, CTB-SAP downregulated AGT, Ang II, AT1R, NOX2, catalase, MCP-1, IL-6, fibronectin, and collagen I, and upregulated ACE2 and Mas receptor. Targeted dCSF-CNs ablation could alleviate renal inflammation and fibrosis in chronic kidney injury.

Usage: CTB-SAP (500 ng) into the lateral ventricles over a 3-min period.

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Exercise is neuroprotective following partial motoneuron depletion: Run for your dendrites

Chew C, Sengelaub DR (2018) Exercise is neuroprotective following partial motoneuron depletion: Run for your dendrites. Neuroscience 2018 Abstracts 761.02 / MM11. Society for Neuroscience, San Diego, CA.

Summary: We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy in remaining motoneurons. Furthermore, systemic treatment with supplemental androgens is neuroprotective and dendritic atrophy following partial motoneuron depletion is attenuated. Circulating levels of androgens have previously been shown to increase following exercise, and exercise has been demonstrated to be neuroprotective in a variety of other neurodegenerative and injury models. Thus, we hypothesized that allowing animals to exercise following partial motoneuron depletion would produce neuroprotective effects similar to treatment with supplemental androgens. Motoneurons innervating the vastus medialis muscle in adult male rats were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Following saporin injections, some animals were allowed free access to a running wheel attached to their home cages. Four weeks later, motoneurons innervating the ipsilateral vastus lateralis muscle were labeled with cholera toxin-conjugated horseradish peroxidase, and dendritic arbors were reconstructed in three dimensions. Compared with intact normal males, partial motoneuron depletion resulted in decreased dendritic length in remaining quadriceps motoneurons. Early data suggests that exercise can completely protect against this dendritic atrophy, with exercised males showing dendritic arbors lengths significantly longer than saporin and testosterone-treated animals, and of similar length to intact normal animals. These findings suggest that exercise may be a viable means of protecting against collateral dendritic atrophy. The upregulation of testosterone release following exercise combined with our previous data showing the neuroprotective effects of androgen treatment suggest that the neuroprotective following exercise may be attributable to systemic androgen upregulation.

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Hypoglossal motor neuron death via intralingual CTB-saporin (CTB-SAP) injections mimic aspects of amyotrophic lateral sclerosis (ALS) related to dysphagia

Lind LA, Murphy ER, Lever TE, Nichols NL (2018) Hypoglossal motor neuron death via intralingual CTB-saporin (CTB-SAP) injections mimic aspects of amyotrophic lateral sclerosis (ALS) related to dysphagia. Neuroscience 390:303-316. doi: 10.1016/j.neuroscience.2018.08.026

Objective: Despite its fundamental importance, dysphagia (difficulty swallowing) and strategies to preserve swallowing function have seldom been studied in ALS models.

Summary: The authors report a novel experimental model using intralingual injections of cholera toxin B conjugated to saporin (CTB-SAP) to study the impact of only hypoglossal motor neuron death without the many complications that are present in ALS models.

Usage: Hypoglossal motor neuron survival, swallowing function, and hypoglossal motor output were assessed in Sprague Dawley rats after intralingual injection of either CTB-SAP (25 ug) or unconjugated CTB and SAP (controls) into the genioglossus muscle.

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Targeted ablation of cardiac sympathetic neurons attenuates adverse post-infarction remodeling and left ventricle dysfunction.

Xiong L, Liu Y, Zhou M, Wang G, Quan D, Shuai W, Shen C, Kong B, Huang C, Huang H (2018) Targeted ablation of cardiac sympathetic neurons attenuates adverse post-infarction remodeling and left ventricle dysfunction. Exp Physiol 103:1221-1229. doi: 10.1113/EP086928

Objective: To determine whether targeted ablation of cardiac sympathetic neurons (TACSN) could suppress myocardial infarction-induced adverse cardiac remodeling and left ventricle dysfunction.

Summary: TACSN significantly alleviated sympathetic remodeling and neuroendocrine activation, attenuated cardiac hypertrophy and fibrosis, and improved the left ventricular function. Thus, TACSN may have a beneficial effect on adverse post-infarction remodeling and left ventricle dysfunction.

Usage: 20 μl of CTB-SAP (1.2 mg/ml) was mixed with 4 μl of 3% Evans blue dye to make it visible (CTB-SAP is colorless), ensuring localization within the ganglia. The CTB-SAP/Evans blue dye solution was slowly and intermittently injected into the left stellate ganglia using a glass micropipette.

Related Products: CTB-SAP (Cat. #IT-14)

The establishment of a CSF-contacting nucleus “knockout” model animal.

Song SY, Zhang LC (2018) The establishment of a CSF-contacting nucleus "knockout" model animal. Front Neuroanat 12:22. doi: 10.3389/fnana.2018.00022

Objective: To establish a cerebrospinal fluid (CSF)-contacting nucleus-deficient model animal using cholera toxin B subunit-saporin (CTB-SAP).

Summary: The complete ablation occurred by Day 7 after CTB-SAP microinjection. A model animal that had no CSF-contacting nucleus was established after survival beyond that time point. No obvious effects were observed in the vital status of the model animals, and their survival was ensured. The common physiological parameters of model animals were stable. The present study provides a method to establish a CSF-contacting nucleus “knockout” model animal, which is similar to a gene knockout model animal for studying this particular nucleus in vivo.

Usage: 3 μl (500 ng) CTB-SAP was microinjected into the lateral ventricle.

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Phrenic long-term facilitation following intrapleural CTB-SAP-induced respiratory motor neuron death.

Nichols NL, Craig TA, Tanner MA (2018) Phrenic long-term facilitation following intrapleural CTB-SAP-induced respiratory motor neuron death. Respir Physiol Neurobiol 256:43-49. doi: 10.1016/j.resp.2017.08.003

Objective: To study the impact of respiratory motor neuron death.

Summary: Intrapleural CTB-SAP mimics aspects of ALS. Seven days of CTB-SAP enhances respiratory plasticity.

Usage: Bilateral intrapleural injections of: 1) CTB-SAP (25 μg), or 2) unconjugated CTB and SAP (control).

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

Sonic hedgehog and TDP-43 participate in the spontaneous locomotor recovery in a mouse model of spinal motoneuron disease

Gulino R, Parenti R, Gulisano M (2017) Sonic hedgehog and TDP-43 participate in the spontaneous locomotor recovery in a mouse model of spinal motoneuron disease. J Funct Morphol Kinesiol 2:11.. doi: 10.3390/jfmk2020011

Summary: The authors used a mouse model of neurotoxic motoneuron depletion to study the role of Sonic hedgehog and TDP-43 in the compensatory changes occurring after the lesion. The injection of cholera toxin-B saporin (CTB-SAP; Cat. #IT-14) into the gastrocnemius muscle caused a partial motoneuron death accompanied by an impairment of locomotion.  Motor activity was significantly restored as soon as one month later.

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Novel targets for modulation of plasticity in a mouse model of motoneuron degeneration.

Gulino R, Forte S, Parenti R, Gulisano M (2016) Novel targets for modulation of plasticity in a mouse model of motoneuron degeneration. Neuroscience 2016 Abstracts 812.14 / OO13. Society for Neuroscience, San Diego, CA.

Summary: A successful spinal cord repairing strategy should involve the activation of neural precursor cells. Unfortunately, their ability to generate neurons aſter injury appears limited. Another process promoting functional recovery is synaptic plasticity. We have previously studied some mechanisms of spinal plasticity by using a mouse model of motoneuron depletion induced by cholera toxin-B saporin. TDP-43 is a nuclear RNA/DNA binding protein involved in amyotrophic lateral sclerosis. Although considerable attention has been devoted to the toxic effects of the TDP-43 cytoplasmic aggregates, the functional role of this factor remains poorly investigated. Notably, TDP-43 is present in the dendrites where it behaves as a modulator of local RNA translation. Moreover, it is crucial for synaptic plasticity and locomotion in Drosophila. Here, we would like to deepen the investigation of this model of spinal plasticity. Aſter lesion, we observed a glial reaction and an activity-dependent modification of Synapsin-I, Shh, Noggin, Numb and TDP-43 proteins. Multivariate regression was used to model the possible association between these proteins, as well as with the motor performance. We found that Shh and Noggin could affect motor performance and that these proteins could be associated with both TDP-43 and Numb, thus suggesting that TDP-43 is likely an important regulator of synaptic plasticity. Given the well-known role of morphogens such as Shh, Noggin and Numb in neurogenesis and the above described functions of TDP-43, we believe that an in vivo manipulation of their signaling pathways after lesion could represent a putative method of improving regeneration and recovery by affecting synaptic plasticity and/or neurogenesis.

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Neuroprotective effects of testosterone metabolites and dependency on receptor action on the morphology of somatic motoneurons following the death of neighboring motoneurons.

Cai Y, Chew C, Muñoz F, Sengelaub D (2017) Neuroprotective effects of testosterone metabolites and dependency on receptor action on the morphology of somatic motoneurons following the death of neighboring motoneurons. Dev Neurobiol 77:691-707.. doi: 10.1002/dneu.22445

Summary: In this study the authors examined whether the protective effects of testosterone could be mediated via its androgenic or estrogenic metabolites and if these neuroprotective effects were mediated through steroid hormone receptors. Analysis was done using receptor antagonists to attempt to prevent the neuroprotective effects of hormones after partial motoneuron depletion. These motoneurons were selectively killed by intramuscular injection of CTB-SAP (2 ul, 0.1%) (Cat. #IT-14). Compared with intact normal animals, partial motoneuron depletion resulted in decreased dendritic length in remaining quadriceps motoneurons. Dendritic atrophy was attenuated with both dihydrotestosterone and estradiol treatment to a degree similar to that seen with testosterone and attenuation of atrophy was prevented by receptor blockade. Together, the results suggest that neuroprotective effects on motoneurons can be mediated by either androgenic or estrogenic hormones and require action via steroid hormone receptors, further supporting a role for hormones as neurotherapeutic agents in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Role of the RVM in descending pain regulation originating from the cerebrospinal fluid-contacting nucleus.

Fei Y, Wang X, Chen S, Zhou Q, Zhang C, Li Y, Sun L, Zhang L (2016) Role of the RVM in descending pain regulation originating from the cerebrospinal fluid-contacting nucleus. Neurochem Res 41:1651-1661. doi: 10.1007/s11064-016-1880-6

Summary: The researchers investigated whether the CSF-contacting nucleus contributed to descending pain modulation in normal and neuropathic rats, and detected the 5-HT expression changes in both RVM and spinal dorsal cord. They also detected the possible anatomical and function correlation between the CSF-contacting nucleus and the RVM. Targeted ablation of the CSF-contacting nucleus was performed using CTB-SAP (Cat. #IT-14; 500 ng/3 μl), which was administered i.c.v. to the normal rats and rats 7 days before the CCI procedure. Based on the findings of the present study, they believe that the CSF-contacting nucleus may act as a component of descending pain regulation system. RVM, which acts as an important brain nucleus, is involved in the relay of nociceptive information between the CSF-contacting nucleus and spinal cord. Moreover, RVM 5-HT system plays a critical role in descending pain inhibition originating from the CSF-contacting nucleus.

Related Products: CTB-SAP (Cat. #IT-14)

Neuroplasticity and repair in rodent neurotoxic models of spinal motoneuron disease.

Gulino R (2016) Neuroplasticity and repair in rodent neurotoxic models of spinal motoneuron disease. Neural Plast 2016:2769735. doi: 10.1155/2016/2769735

Summary: TDP-43 (Transactive response DNA-binding protein) is a highly conserved nuclear protein that binds both DNA and RNA. It has been found in cytoplasmic protein aggregates of patients with conditions such as amyotrophic lateral sclerosis and Alzheimer’s disease. In this work the authors examine the role of TDP-43 in spinal cord plasticity. Mice received bilateral 3-μg injections of CTB-SAP (Cat. #IT-14) into the lateral and medial gastrocnemius muscles. The results indicate that motor performance is dependent on expression of synapsin-I, which in turn may be dependent on TDP-43.

Related Products: CTB-SAP (Cat. #IT-14)

Targeted ablation of cardiac sympathetic neurons: A promising approach to prevent sudden cardiac death.

Xia W, Liu Y (2016) Targeted ablation of cardiac sympathetic neurons: A promising approach to prevent sudden cardiac death. Int J Cardiol 202:425-426. doi: 10.1016/j.ijcard.2015.09.049

Summary: Sudden cardiac death (SCD) refers to an unexpected death due to cardiovascular causes, occurring generally within 1 hr of symptom onset, in a person without any prior condition that would appear fatal. Currently, the implantable cardioverter-defibrillator (ICD) has been shown to be the most effective therapy for preventing SCD. However, the occurrence of lead complications is significant and more importantly, the ICD implantation remains costly and the quality of life for recipients is significantly affected with appropriate and inappropriate shocks. Sympathetic activation plays an important role in the pathophysiology of arrhythmias leading to SCD, and neuraxial modulation is emerging as an important avenue of therapeutic intervention. The authors demonstrate that targeted ablation of cardiac sympathetic neurons by bilateral stellate ganglia injection of CTB-SAP (Cat. #IT-14) is a novel method for sympathetic blockade. CTB-SAP will be retrogradely transported to the plasma membranse of sympathetic preganglionic neurons (SPNs) and bind to the GM1 gangliosides and subsequently ablate these neurons. Targeted ablation of cardiac sympathetic neurons by injection of CTB-SAP avoids the limitations of medical therapy and thoracic sympathectomy, such as incomplete compliance, Horner’s syndrome, and compensatory hyperhidrosis. Furthermore, they found that targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sustained ventricular tachycardia, associated with a reduced number of neurons in the stellate ganglia and spinal cord, as well as a reduced left ventricular norepinephrine content and sympathetic innervation density. Therefore, targeted ablation of cardiac sympathetic neurons may be a promising approach to prevent SCD via regulating the cardiac autonomic nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Neuroprotection with androgens following partial motoneuron depletion: A role for microglia

Kiley BJ, Sengelaub DR (2015) Neuroprotection with androgens following partial motoneuron depletion: A role for microglia. Neuroscience 2015 Abstracts 689.18/K11. Society for Neuroscience, Chicago IL.

Summary: Neurodegenerative disease or nerve injury results in the loss of spinal motoneurons, and remaining motoneurons show a variety of morphological and functional changes. We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy in remaining motoneurons, with 70% decreases in dendritic length. Treatment with testosterone is neuroprotective, and dendritic atrophy following partial motoneuron depletion is attenuated. In the present study, we explored a potential mechanism for this induced atrophy and the protection by androgen treatment, examining the response of microglia to the partial depletion of motoneurons with and without testosterone treatment. Microglia are activated locally and recruited from other sites in response to injury. Microglia are involved in the removal of synapses and dendrites after injury, and there is evidence that their activation is influenced by steroid hormones. Motoneurons innervating the vastus medialis muscle in adult male rats were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, saporin-injected rats were given systemic treatments via interscapular implants containing testosterone or left blank. One or three weeks later, microglia were visualized after immunohistochemical staining for Iba1. Microglia surrounding the injured motoneurons were classified as monitoring or activated (primed, reactive, or ameboid) based on morphology and counted stereologically. Compared with intact males, partial motoneuron depletion resulted in increases in the total number of microglia (78% and 24% at 1 and 3 weeks post-saporin, respectively) in the quadriceps motor pool. These changes were driven by increases in the number of activated microglia compared to levels found in intact animals; the number of activated microglia increased by 144% at 1 week post-saporin, and remained elevated at 3 weeks (51%). The increases in the number of activated microglia were attenuated with testosterone treatment; the number of activated forms increased only 34% and 17% at 1 and 3 weeks post-saporin, respectively. These findings suggest that the dendritic atrophy observed in remaining motoneurons after partial motoneuron depletion could be a result of increased microglial activation in the injury site, resulting in collateral damage through synaptic stripping and dendritic loss. The attenuation of both dendritic atrophy and microglial activation with testosterone treatment supports this potential causal effect, and further supports a role for hormones as neurotherapeutic agents in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Role of cerebrospinal fluid-contacting nucleus in sodium sensing and sodium appetite.

Xing D, Wu Y, Li G, Song S, Liu Y, Liu H, Wang X, Fei Y, Zhang C, Li Y, Zhang L (2015) Role of cerebrospinal fluid-contacting nucleus in sodium sensing and sodium appetite. Physiol Behav 147:291-299. doi: 10.1016/j.physbeh.2015.04.034

Summary: Sodium concentration in the cerebrospinal fluid (CSF) is tightly regulated, and this regulation requires numerous sensors spread throughout the brain. Here the authors injected 900 ng CTB-SAP (Cat. #IT-14) into the lateral ventricles. Investigation of spontaneous and induced sodium intake indicates the CSF-contacting nucleus is an important link in the sodium sensing network, and interacts with the lateral parabrachial nucleus.

Related Products: CTB-SAP (Cat. #IT-14)

Respiratory function after selective respiratory motor neuron death from intrapleural CTB-saporin injections.

Nichols N, Vinit S, Bauernschmidt L, Mitchell G (2015) Respiratory function after selective respiratory motor neuron death from intrapleural CTB-saporin injections. Exp Neurol 267:18-29. doi: 10.1016/j.expneurol.2014.11.011

Summary: Amyotrophic lateral sclerosis (ALS) ultimately causes death from ventilator failure. Genetic models of ALS suffer from high variability of the rate, timing, and extent of respiratory motor neuron death. The authors created a novel model of induced respiratory motor neuron death using CTB-SAP (Cat. #IT-14). Rats received 25 μg or 50 μg intrapleural injections of CTB-SAP; Saporin (Cat. #PR-01) was used as a control. After 7 days, motor neuron survival approximated what is seen in end-stage ALS rats, while there was minimal cell death in other brainstem or spinal cord regions. CTB-SAP also caused microglial activation, decreased breathing during chemoreceptor stimulation, and diminished phrenic motor output in anesthetized rats – all hallmarks of ALS.

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

Novel mechanisms of spinal cord plasticity in a mouse model of motoneuron disease.

Gulino R, Parenti R, Gulisano M (2015) Novel mechanisms of spinal cord plasticity in a mouse model of motoneuron disease. Biomed Res Int 2015:654637. doi: 10.1155/2015/654637

Summary: Here the authors investigate spinal plasticity mechanisms involving a number of different proteins, including BDNF, Shh, Notch-1, Numb, and Noggin. The model used is a mouse motoneuron depletion strategy, where the animals receive 3 μg of CTB-SAP (Cat. #IT-14) into each of the medial and lateral gastrocnemius muscles. The results indicate that TDP-43, a nuclear DNA/RNA binding protein, may be an important regulator of synaptic plasticity.

Related Products: CTB-SAP (Cat. #IT-14)

Role of adrenomedullin in the cerebrospinal fluid-contacting nucleus in the modulation of immobilization stress.

Wu Y, Song S, Liu H, Xing D, Wang X, Fei Y, Li G, Zhang C, Li Y, Zhang L (2015) Role of adrenomedullin in the cerebrospinal fluid-contacting nucleus in the modulation of immobilization stress. Neuropeptides 51:43-54. doi: 10.1016/j.npep.2015.03.007

Summary: The CSF-contacting nucleus (CSF-CN) is a brain structure containing neurons that can bidirectionally transmit signals between the brain parenchyma and the CSF. In order to better understand what regulatory peptides modulate this organ, the authors eliminated the CSF-CN of rats with a 500-ng icv injection of CTB-SAP (Cat. #IT-14). Saporin (Cat. #PR-01) was used as a control. The elimination of the CSF-CN worsened the response to chronic immobilization stress; with other data this information suggests that the CSF-CN uses adrenomedullin as a stress-related peptide.

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

Role of the cerebrospinal fluid-contacting nucleus in the descending inhibition of spinal pain transmission.

Liu H, Yan W, Lu X, Zhang X, Wei J, Wang X, Wang T, Wu T, Cao J, Shao C, Zhou F, Zhang H, Zhang P, Zang T, Lu X, Cao J, Ding H, Zhang L (2014) Role of the cerebrospinal fluid-contacting nucleus in the descending inhibition of spinal pain transmission. Exp Neurol 261:475-485. doi: 10.1016/j.expneurol.2014.07.018

Summary: The first synapse in the pain pathway is in the spinal dorsal horn, and several sites are involved in the descending control of pain. Previous studies have suggested that cerebrospinal fluid-contacting neurons may facilitate signal transmission and substance transport between the brain parenchyma and the CSF, including processes that modulate pain transmission. The authors administered CTB-SAP (Cat. #IT-14) into the right lateral ventricle of rats. Saporin (Cat. #PR-01) was used as a control. The results indicate that the 5-HT pathway contacting the CSF is an important piece in the descending inhibitory system controlling spinal transmission of pain.

Related Products: CTB-SAP (Cat. #IT-14), Saporin (Cat. #PR-01)

[Targeted damage of the cerebrospinal fluid-contacting nucleus contributes to the pain behavior and the expression of 5-HT and c-Fos in spinal dorsal horn of rats].

Cao J, Wu T, Zhang L (2014) [Targeted damage of the cerebrospinal fluid-contacting nucleus contributes to the pain behavior and the expression of 5-HT and c-Fos in spinal dorsal horn of rats]. Zhongguo Ying Yong Sheng Li Xue Za Zhi 30:218-222.

Summary: Pain threshold, 5-hydroxytryptamine (5-HT) expression, and c-Fos expression were measured in rats after treatment with CTB-SAP (Cat. #IT-14). Use of CTB-SAP reduced the number of neurons in the cerebrospinal fluid (CSF)-contacting nucleus over time until no neurons could be detected by the 10th day post-injection. 5-HT and c-Fos expression in the spinal dorsal horn gradually increased, and was negatively correlated with the pain threshold. The data indicate that neurons in the CSF-contacting nucleus are involved in pain regulation, and that expression of 5-HT and c-Fos is part of this regulatory pathway.

Related Products: CTB-SAP (Cat. #IT-14)

Noggin and Sonic hedgehog are involved in compensatory changes within the motoneuron-depleted mouse spinal cord.

Gulino R, Gulisano M (2013) Noggin and Sonic hedgehog are involved in compensatory changes within the motoneuron-depleted mouse spinal cord. J Neurol Sci 332(1-2):102-109. doi: 10.1016/j.jns.2013.06.029

Summary: Noggin (NOG) and Sonic hedgehog (Shh) are both involved in the generation and organization of neural tissues. In order to clarify the role of these two proteins in the regulation of neurogenesis and/or neuroplasticity the authors used a motoneuron depletion model in the mouse spinal cord. 3 μg of CTB-SAP (Cat. #IT-14) was injected into each of the medial and lateral gastrocnemius muscles and the expression of NOG and Shh were monitored. Motor performance also correlated with NOG and Shh levels, indicating that these proteins could play roles in regeneration and functional restoration.

Related Products: CTB-SAP (Cat. #IT-14)

Neural plasticity in injured spinal cord.

Gulisano M, Parenti R, Gulino R (2012) Neural plasticity in injured spinal cord. Neuroscience 2012 Abstracts 846.09. Society for Neuroscience, New Orleans, LA.

Summary: Sonic hedgehog and Noggin are morphogenetic factors involved in neural induction and ventralization of the neural tube, but recent findings suggest that they could participate in regeneration and functional recovery after injury. Here, in order to verify if these mechanisms could occur in the spinal cord and involve synaptic plasticity, we measured the expression levels of Sonic hedgehog, Noggin, Choline acetyltransferase, Synapsin-I, and Glutamate receptor subunits (GluR1, GluR2, GluR4), in a motoneuron-depleted mouse spinal lesion model obtained by intramuscular injection of Cholera toxin-B saporin. The lesion caused differential expression changes of the analyzed proteins. Moreover, motor performance was found correlated with Sonic hedgehog and Noggin expression in lesioned animals. The results also suggest that Sonic hedgehog could collaborate in modulating synaptic plasticity. Together, these findings confirm that the injured mammalian spinal cord has intrinsic potential for repair and that some proteins classically involved in development, such as Sonic hedgehog and Noggin could have important roles in regeneration and functional restoration, by mechanisms including synaptic plasticity.

Related Products: CTB-SAP (Cat. #IT-14)

Involvement of brain-derived neurotrophic factor and sonic hedgehog in the spinal cord plasticity after neurotoxic partial removal of lumbar motoneurons.

Gulino R, Gulisano M (2012) Involvement of brain-derived neurotrophic factor and sonic hedgehog in the spinal cord plasticity after neurotoxic partial removal of lumbar motoneurons. Neurosci Res 73(3):238-247. doi: 10.1016/j.neures.2012.04.010

Summary: In this work the authors created a motoneuron depletion with bilateral 6.0-μg injections of CTB-SAP (Cat. #IT-14) into the medial and lateral gastrocnemius muscles of rats. The results indicate BDNF and sonic hedgehog may collaborate in modulating synaptic plasticity after loss of motoneurons.

Related Products: CTB-SAP (Cat. #IT-14)

A central role for BDNF and Sonic Hedgehog in controlling synaptic plasticity in motoneuron-depleted spinal cord

Gulino R, Gulisano M (2011) A central role for BDNF and Sonic Hedgehog in controlling synaptic plasticity in motoneuron-depleted spinal cord. IBRO 2011 Abstracts International Brain Research Organization, Florence, Italy.

Summary: Here, we measured the expression levels of several proteins involved in synaptic plasticity and motoneuronal function (ChAT, Synapsin-I, Shh, Notch-1, AMPA receptor subunits, NMDA receptor and BDNF) in a mouse SC lesion model obtained by intramuscular injection of Cholera toxin-B-saporin, which selectively kills motoneurons

Related Products: CTB-SAP (Cat. #IT-14)

Cerebellar modules: individual or composite entities?

Cerminara NL (2010) Cerebellar modules: individual or composite entities?. J Neurosci 30(48):16065-16067. doi: 10.1523/JNEUROSCI.4823-10.2010

Summary: This short review discusses the compartmentalization of cerebellar modules. Much research has been done to associate particular motor control functions with particular modules. Chemical lesioning is an inadequate technique because the lesion is non-specific. The use of CTB-SAP (Cat. #IT-14) to affect the function of a single module is discussed.

Related Products: CTB-SAP (Cat. #IT-14)

The recovery of locomotion after lumbar spinal cord motoneuron depletion is affected by the modulation of Sonic Hedgehog and Notch-1 pathways

Gulino R, Gulisano M (2010) The recovery of locomotion after lumbar spinal cord motoneuron depletion is affected by the modulation of Sonic Hedgehog and Notch-1 pathways. Neuroscience 2010 Abstracts 259.19/W12. Society for Neuroscience, San Diego, CA.

Summary: Sonic hedgehog (Shh) and Notch-1 are involved in the regulation of stem cell function. Additionally, Notch-1 has a role as modulator of synaptic plasticity. In our previous work, we injected Cholera toxin-B saporin (CTB-sap) into the gastrocnemius muscle to induce a selective depletion of motoneurons within lumbar mice spinal cord (SC) and analysed the expression levels of Shh, Notch-1, Numb, Choline acetyltransferase (ChAT) and Synapsin-I proteins. The functional outcome of the lesion was monitored by grid walk test and rotarod. Shh and Notch-1 appeared reduced in the lesioned tissue and correlated with ChAT and Synapsin-I levels, suggesting a role in modulating synaptic plasticity. Numb expression was also reduced after lesion and appeared correlated with motor performance but not with synaptic plasticity. We sought to determine if the pharmacological manipulation of the expression of Shh and Notch-1 could affect functional recovery by a mechanism involving synaptic plasticity. Therefore, we used CTB-sap to induce lesion as above, and injected Cyclopamine, recombinant Shh or recombinant DLL4 chronically into the intrathecal space by means of osmotic minipumps for two weeks. The functional recovery was monitored for one month after lesion by means of grid walk test, two times a week, whereas the modifications of Shh, Notch-1, ChAT and Synapsin-I protein expression levels were measured by western blot and immunohistochemistry. Here, we show that the modulation of Shh or Notch-1 pathways could affect the recovery of locomotion. Moreover, the molecular mechanisms underlying this process is discussed.

Related Products: CTB-SAP (Cat. #IT-14)

Expression of cell fate determinants and plastic changes after neurotoxic lesion of adult mice spinal cord by cholera toxin-B saporin.

Gulino R, Perciavalle V, Gulisano M (2010) Expression of cell fate determinants and plastic changes after neurotoxic lesion of adult mice spinal cord by cholera toxin-B saporin. Eur J Neurosci 31(8):1423-1434. doi: 10.1111/j.1460-9568.2010.07170.x

Summary: Sonic hedgehog, Notch-1, and Numb are proteins known to be involved in the function of stem cells. Understanding of how they might work in adults may provide methods to improve recovery from spinal cord injury. In this work the authors injected 3 µg of CTB-SAP (Cat. #IT-14) into the medial and lateral gastrocnemius muscles of mice. Analysis of protein levels following motoneuron depletion gives some insight into the molecular framework of nerve injury.

Related Products: CTB-SAP (Cat. #IT-14)

Read the featured article in Targeting Trends.

Targeted ablation of mesenteric projecting sympathetic neurons reduces the hemodynamic response to pain in conscious spinal cord transected rats.

Lujan HL, Palani G, Peduzzi J, Dicarlo SE (2010) Targeted ablation of mesenteric projecting sympathetic neurons reduces the hemodynamic response to pain in conscious spinal cord transected rats. Am J Physiol Regul Integr Comp Physiol 298(5):R1358-1365. doi: 10.1152/ajpregu.00755.2009

Summary: Autonomic dysreflexia is a life-threatening hypertension as a result of a spinal cord injury above thoracic level 6. The authors investigated whether reduction of sympathetic activity can reduce the severity of this condition. Rats received 13.5 µg injections of CTB-SAP (Cat. #IT-14) into the celiac ganglion resulting in ablation of mesenteric projecting sympathetic neurons. Lesioned animals displayed a reduced pressor response to pain after spinal cord transection, to some extent ameliorating autonomic dysreflexia.

Related Products: CTB-SAP (Cat. #IT-14)

Read the featured article in Targeting Trends.

Targeted ablation of cardiac sympathetic neurons reduces the susceptibility to ischemia-induced sustained ventricular tachycardia in conscious rats.

Lujan HL, Palani G, Zhang L, Dicarlo SE (2010) Targeted ablation of cardiac sympathetic neurons reduces the susceptibility to ischemia-induced sustained ventricular tachycardia in conscious rats. Am J Physiol Heart Circ Physiol 298:H1330-H1339. doi: 10.1152/ajpheart.00955.2009

Summary: It has been shown that reduction of cardiac sympathetic activity protects against ventricular tachy-arrhythmias, which are the leading cause of death in industrially developed countries. Rats received 10 µg injections of CTB-SAP (Cat. #IT-14) into each stellate ganglia. Using comparison of ventricular tachycardia onset times after coronary artery occlusion it was found that lesioned rats were less susceptible to tachycardia events.

Related Products: CTB-SAP (Cat. #IT-14)

Read the featured article in Targeting Trends.

Neuroprotective effects of testosterone on dendritic morphology following partial motoneuron depletion: efficacy in female rats.

Wilson RE, Coons KD, Sengelaub DR (2009) Neuroprotective effects of testosterone on dendritic morphology following partial motoneuron depletion: efficacy in female rats. Neurosci Lett 465:123-127. doi: 10.1016/j.neulet.2009.09.007

Summary: Previous work has demonstrated a protective effect from testosterone in a motoneuron nerve injury model for male rats. This work investigated whether testosterone has the same effect in females. Female rats received 2 µg of CTB-SAP (Cat. #IT-14) into the left vastus medialis muscle. 4 weeks later surviving motoneurons were visualized with CTB conjugated to HRP. Testosterone treatment greatly attenuated the atrophy seen in control animals, suggesting that testosterone is also a neurotherapeutic agent in females.

Related Products: CTB-SAP (Cat. #IT-14)

Dendritic atrophy following partial motoneuron depletion: Time course of recovery and protection with androgens and estrogens.

Coons KD, Munoz F, Osborne MC, Sengelaub DR (2009) Dendritic atrophy following partial motoneuron depletion: Time course of recovery and protection with androgens and estrogens. Neuroscience 2009 Abstracts 743.2/R17. Society for Neuroscience, Chicago, IL.

Summary: We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy and loss of function in remaining motoneurons. Furthermore, treatment with testosterone is neuroprotective, and dendritic atrophy and loss of function following partial motoneuron depletion are attenuated in a dose-dependent fashion, and in both male and female rats. In the present study, we assessed dendritic atrophy after partial motoneuron depletion at a variety of time points to determine its time course and pattern with and without testosterone treatment. We also examined the potential neuroprotective effects of the androgenic and estrogenic metabolites of testosterone. Motoneurons innervating the vastus medialis muscle were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, saporin-injected males were given implants containing either testosterone (45mm), dihydrotestosterone (30mm), estradiol (10%, 10mm), or left untreated. At 2, 4, 6, or 10 weeks after partial motoneuron depletion, motoneurons innervating the ipsilateral vastus lateralis muscle were labeled with cholera toxin-conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. Animals treated with dihydrotestosterone or estradiol were assessed only at 4 weeks post depletion. Dendritic arbors were also assessed in a group of untreated normal males. Quadriceps motoneuron dendrites underwent a rapid atrophy and protracted recovery following partial motoneuron depletion. Dendritic atrophy in remaining quadriceps motoneurons was apparent at 2 weeks after motoneuron depletion, with a decrease of over 50% in dendritic length, and this atrophy remained through 6 weeks post-depletion; dendritic length recovered by 10 weeks post-depletion. Treatment with testosterone attenuated induced dendritic atrophy at all time points, and recovery to normal lengths was present at 6 weeks post-depletion. Treatment with dihydrotestosterone or estradiol was as effective as testosterone in attenuating dendritic atrophy in remaining quadriceps motoneurons. These results suggest that treatment with testosterone is neuroprotective, both attenuating induced dendritic atrophy and accelerating recovery. Furthermore, this effect can be achieved with both androgenic and estrogenic metabolites, further supporting a role for hormones as neurotherapeutic agents in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Poster: Expression of cell fate determinants and plastic changes after neurotoxic lesion of adult mice spinal cord by cholera toxin-B saporin.

Gulino R, Gulisano M (2009) Poster: Expression of cell fate determinants and plastic changes after neurotoxic lesion of adult mice spinal cord by cholera toxin-B saporin. Neuroscience 2009 Abstracts 563.15/DD51. Society for Neuroscience, Chicago, IL.

Summary: Recent studies have attempted to achieve recovery after spinal cord (SC) injury or disease by either increase neurogenesis or stimulate neuroplasticity. Sonic hedgehog (Shh) Notch-1 and Numb are involved in the regulation of stem cell function. Additionally, Notch-1 has a role as modulator of synaptic plasticity. Little is known about the role of these proteins in the adult SC after selective removal of motoneurons. We injected Cholera toxin-B saporin into the gastrocnemius muscle to induce a selective depletion of motoneurons within lumbar mice SC and analysed the expression levels of Shh, Notch-1, Numb, Choline acetyltransferase (ChAT) and Synapsin-I proteins. The functional outcome of the lesion was monitored by grid walk test and rotarod. The neurotoxin lesion determined a motoneuron depletion and a decrease of ChAT and Synapsin-I protein levels in the lumbar SC. ChAT and Synapsin-I appeared correlated each other and with the motor performance, suggesting that the recovery of locomotion could depend from synaptic plasticity. Moreover, we observed a number of proliferating cells within the depleted SC, which were identified as active astrocytes. Shh and Notch-1 appeared reduced in the lesioned tissue and correlated with ChAT and Synapsin-I levels, suggesting a role in modulating synaptic plasticity. Numb expression was also reduced after lesion and appeared correlated with motor performance Therefore, given the role of these proteins in adult neurogenesis, we presume their involvement also in the observed glial reaction. The in vivo manipulation of Shh, Notch-1 and Numb signalling after lesion could be a way to reduce glial reaction and improve functional recovery.

Related Products: CTB-SAP (Cat. #IT-14)

Neuroprotective effect of testosterone treatment on motoneuron recruitment following the death of nearby motoneurons.

Fargo KN, Foster AM, Sengelaub DR (2009) Neuroprotective effect of testosterone treatment on motoneuron recruitment following the death of nearby motoneurons. Dev Neurobiol 69:825-835. doi: 10.1002/dneu.20743

Summary: Previous work has demonstrated that testosterone treatment can prevent dendritic atrophy due to death of nearby motoneurons. This experiment examined whether this protection extends to motor activation. Rats received a 1 µg injection of CTB-SAP (Cat. #IT-14) into each of the right bulbocavernosus and levator ani muscles. Animals treated with testosterone preserved more of the activity duration than untreated animals, as well as no decrease in motoneuron recruitment.

Related Products: CTB-SAP (Cat. #IT-14)

Targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sympathetic activation in conscious rats.

Lujan HL, Palani G, Chen Y, Peduzzi JD, Dicarlo SE (2009) Targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sympathetic activation in conscious rats. Am J Physiol Heart Circ Physiol 296:H1305-H1311. doi: 10.1152/ajpheart.00095.2009

Summary: This work examines the capability of CTB-SAP (Cat. #IT-14) to eliminate cardiac sympathetic neurons. The right and left stellate ganglia of rats were each injected with 10 µg of CTB-SAP. Lesioned animals displayed physiolo-gical differences from controls, as well as specific reduction of numbers of neurons in the stellate ganglion and spinal cord.

Related Products: CTB-SAP (Cat. #IT-14)

Recent progress in research on ribosome inactivating proteins.

Ng TB, Wong JH, Wang H (2009) Recent progress in research on ribosome inactivating proteins. Curr Protein Pept Sci 1323:94-108. doi: 10.2174/138920310790274662

Summary: This review discusses recent literature on ribosome inactivating proteins including the use of saporin-based conjugates in neuroscience and cancer research. Brief descriptions of research done using 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02), dermorphin-SAP (Cat. #IT-12), anti-SERT-SAP (Cat. #IT-23), SSP-SAP (Cat. #IT-11), anti-DBH-SAP (Cat. #IT-03), CTB-SAP (Cat. #IT-14), and other conjugates are provided along with basic information about ribosome inactivating proteins.

Related Products: 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02), Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Anti-SERT-SAP (Cat. #IT-23), SSP-SAP (Cat. #IT-11), Anti-DBH-SAP (Cat. #IT-03), CTB-SAP (Cat. #IT-14)

Neuroprotective effects of testosterone on the morphology and function of somatic motoneurons following the death of neighboring motoneurons.

Little CM, Coons KD, Sengelaub DR (2009) Neuroprotective effects of testosterone on the morphology and function of somatic motoneurons following the death of neighboring motoneurons. J Comp Neurol 512:359-372. doi: 10.1002/cne.21885

Summary: Atrophy of androgen-sensitive motoneurons due to proximity to damaged motoneurons can be attenuated by testosterone. This work examined whether typical motoneurons respond in the same way. Rats received 5-ng injections of CTB-SAP (Cat. #IT-14) that eliminated motoneurons innervating the vastus medialis muscle. Partial motoneuron depletion resulted in atrophy of the remaining quadriceps motoneurons; this was attenuated by the administration of testosterone.

Related Products: CTB-SAP (Cat. #IT-14)

Protection from dendritic atrophy with testosterone following partial motoneuron depletion: Timing and duration of treatment, functional correlates in motor activation

Coons KD, Sengelaub DR (2008) Protection from dendritic atrophy with testosterone following partial motoneuron depletion: Timing and duration of treatment, functional correlates in motor activation. Neuroscience 2008 Abstracts 556.23/CC10. Society for Neuroscience, Washington, DC.

Summary: We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy in remaining motoneurons; this atrophy can be attenuated in a dose-dependent fashion, and in both male and female rats, with testosterone (T) treatment. In the present study, we examined (1) how the timing and duration of T treatment affect its ability to attenuate induced atrophy in remaining quadriceps motoneurons, and (2) the effects of induced atrophy and T treatment on subsequent motor function in male rats. Motoneurons innervating the vastus medialis muscles were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Rats were then treated with supplemental T at different times post-saporin injection (immediately, or at 2 or 3 weeks), or for different durations (1, 2, 3, or 4 weeks) or left untreated. All T treatments consisted of subcutaneous implants designed to produce plasma titers in the normal physiological range. Following treatment, the morphology of motoneurons innervating the ipsilateral vastus lateralis muscles was examined using retrograde labeling with cholera toxin-conjugated HRP. In a separate set of rats, quadriceps motoneuron activation was assessed using peripheral nerve recording. Motoneuron morphology and motor activation were also assessed in a group of untreated normal males. Partial motoneuron depletion resulted in dendritic atrophy in remaining quadriceps motoneurons. Treatment with T attenuated this atrophy, but in a time-sensitive manner. Four weeks of T treatment (delivered immediately post-saporin), or two weeks of T treatment (after a delay of two weeks post-saporin) were both effective in attenuating induced dendritic atrophy. However, dendritic atrophy in animals with immediate T treatment of shorter durations or longer delays in the start of treatment was comparable to that of animals who received no supplemental T. Consistent with the morphological changes, partial motoneuron depletion in otherwise untreated males resulted in deficits in motor activation: activation of quadriceps motoneurons required greater stimulus intensities and resulted in decreased amplitudes of motor nerve activity. Importantly, just as observed for dendritic morphology, these changes were attenuated by treatment with supplemental T. These results demonstrate that the neuroprotective effect of T on motoneuron morphology is more dependent on the timing of treatment than on its duration, and also provide a functional correlate of the morphological effects of that treatment, further supporting a role for T as a neurotherapeutic agent in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Sonic hedgehog expression and glial reaction after neurotoxic lesion of adult mice spinal cord by Cholera Toxin-B Saporin

Gulino R, Gulisano M (2008) Sonic hedgehog expression and glial reaction after neurotoxic lesion of adult mice spinal cord by Cholera Toxin-B Saporin. Neuroscience 2008 Abstracts 124.14/B14. Society for Neuroscience, Washington, DC.

Summary: The spinal cord (SC) has ever been considered non-neurogenic because no neurons seem to be generated in the intact SC and only very few recent articles have reported spontaneous generation of new neurons after lesion. Conversely, many studies have demonstrated the occurrence of glial reaction after either mechanical or selective neurotoxic lesion. Sonic hedgehog (Shh) is a member of hedgehog family of secreted glycoproteins, which stimulate cell proliferation as well as neuron and oligodendrocyte differentiation during either development and adulthood. Few data are available about its role in the adult SC after injury. In this study, we used Cholera toxin-B saporin (CTB-sap), a retrogradely transported, ribosome-inactivating toxin, to induce a mild neurotoxic depletion of motoneurons within lumbar SC and to subsequently study the expression levels of Shh and the possible cell proliferation and differentiation within the depleted SC of young adult mice. After an injection of CTB-sap into the gastrocnemius muscle, we found a 30% depletion of lumbar SC motoneurons, and a comparable decrease of ChAT expression levels in the lumbar SC, one week after lesion. Moreover, we found a significant down-regulation of Shh expression, which significantly correlate with ChAT decrease. Both proteins recovered to near normal levels of expression at one month after lesion. The expression of ChAT also correlate with the performance of mice on a grid walk test. So, the observed spontaneous recovery of locomotion was associated with the spontaneous recovery of ChAT and Shh expression. Moreover, we observed a cell proliferation within the depleted SC parenchyma, which was associated with a visible increase of GFAP-positive astrocytes in the same area. Colocalization studies showed that the majority of these proliferating cells are active astrocytes. We hypothesized that Shh expression could have a role in both SC plasticity and the observed glial reaction after neurotoxic lesion. The restoration of normal levels of Shh during the first days after lesion could be a way to partially inhibit glial reaction and to improve functional recovery.

Related Products: CTB-SAP (Cat. #IT-14)

Selective impairment of the cerebellar C1 module involved in rat hind limb control reduces step-dependent modulation of cutaneous reflexes.

Pijpers A, Winkelman BH, Bronsing R, Ruigrok TJ (2008) Selective impairment of the cerebellar C1 module involved in rat hind limb control reduces step-dependent modulation of cutaneous reflexes. J Neurosci 28:2179-2189. doi: 10.1523/JNEUROSCI.4668-07.2008

Summary: The cerebellar cortex is arranged in a series of modules. Elucidation of module-specific function has been difficult because of the closely arranged structure of these modules. Here the authors lesioned the C1/C3 hindlimb module of the rat with CTB-SAP (Cat. #IT-14). Rats received 75-125 ng injections of CTB-SAP into the C1 zone of the copula pyramidis or the paramedian lobule of the right cerebellar hemisphere. C1-injected animals displayed marked diminishment of cutaneously induced reflexes with no significant impact on walking or stepping pattern.

Related Products: CTB-SAP (Cat. #IT-14)

Protection from dendritic atrophy with testosterone following partial motoneuron depletion: dose-dependence in males and efficacy in females

Coons KD, Wilson RE, Sengelaub DR (2007) Protection from dendritic atrophy with testosterone following partial motoneuron depletion: dose-dependence in males and efficacy in females. Neuroscience 2007 Abstracts 56.11/S5. Society for Neuroscience, San Diego, CA.

Summary: Partial depletion of motoneurons from the highly androgen-sensitive spinal nucleus of the bulbocavernosus (SNB), or the more typical somatic motoneuron population innervating the quadriceps muscles, induces dendritic atrophy in remaining motoneurons. Treatment with testosterone (T) is neuroprotective, and dendritic atrophy following partial motoneuron depletion is attenuated in both populations. In the present study, we examined the dose-dependency of T effects in male rats, as well as its potential efficacy in females. Motoneurons innervating the bulbocavernosus/levator ani (BC/LA) or vastus medialis muscles were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, saporin-injected rats were given T implants designed to produce plasma titers ranging from 0.75 to 5.0 ng/ml or left untreated. Four weeks later, motoneurons innervating the contralateral BC or the ipsilateral vastus lateralis muscles were labeled with cholera toxin-conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. Partial motoneuron depletion resulted in dendritic atrophy in remaining SNB and quadriceps motoneurons (40% and 36% of normal length, respectively). T treatment attenuated this atrophy in a dose-dependent manner, with maximum effectiveness at 2.0-2.5 ng/ml (the normal adult physiological level). This dosage of T resulted in SNB dendritic lengths that did not differ from those of intact control males. In contrast, although dendritic atrophy in quadriceps motoneurons was attenuated by the same dosage of T, resultant dendritic lengths were 60% of normal length, and did not improve further with higher levels of T. Neuroprotective effects of T treatment were also assessed in quadriceps motoneurons in female rats (adult female rats lack the SNB neuromuscular system). As described above, motoneurons innervating the vastus medialis muscles were selectively killed by saporin injection, and females were given T implants (resulting in plasma levels of 2.0-2.5 ng/ml) or left untreated. Four weeks later, motoneurons innervating the ipsilateral vastus lateralis muscles were labeled with cholera toxin-conjugated HRP, and dendritic arbors were reconstructed. As in males, partial motoneuron depletion in females resulted in dendritic atrophy (52% of normal length) in remaining quadriceps motoneurons, and this atrophy was attenuated (70% of normal length) with T treatment. Together, these findings suggest that the neuroprotective effects of T on dendrites are achieved with dosages within the normal physiological range, and furthermore can be observed in motoneurons of both male and female rats.

Related Products: CTB-SAP (Cat. #IT-14)

Dendritic atrophy following partial motoneuron depletion: time course of recovery and protection with testosterone

Ferguson AS, Sengelaub DR (2007) Dendritic atrophy following partial motoneuron depletion: time course of recovery and protection with testosterone. Neuroscience 2007 Abstracts 56.24/S18. Society for Neuroscience, San Diego, CA.

Summary: In male rats, motoneurons of the spinal nucleus of the bulbocavernosus (SNB) project to the bulbocavernosus and levator ani (BC/LA) muscles, and both the motoneurons and their target muscles are highly androgen-sensitive. We have previously demonstrated that partial depletion of motoneurons from the SNB induces dendritic atrophy in remaining motoneurons, and that treatment with testosterone (T) is neuroprotective against this atrophy. In the present study, we assessed dendritic atrophy after partial motoneuron depletion in SNB motoneurons at a variety of time points, to determine its time course and pattern with and without T treatment. Motoneurons innervating the BC/LA muscles in gonadally intact males were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, saporin-injected males were given T implants (45mm) or left untreated. At 2, 4, 6, or 10 weeks after motoneuron depletion, motoneurons innervating the contralateral BC were labeled with cholera toxin-conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. As previously reported, partial motoneuron depletion resulted in dendritic atrophy in remaining SNB motoneurons. While motoneuron depletion occurs within 7 days after saporin injection, dendritic atrophy in remaining SNB motoneurons progresses linearly over several weeks, with a decrease of 32% present at 2 weeks after motoneuron depletion, and a decrease to 66% at 4 weeks. Evidence of recovery in dendritic lengths was observed at 6 weeks post depletion (only 43% decreased), and by 10 weeks SNB dendritic lengths had returned to those of normal, intact males. Treatment with T altered the pattern of dendritic atrophy. While initial dendritic atrophy was similar to that of untreated saporin-injected males (29% decreased at 2 weeks post motoneuron depletion), T treatment attenuated dendritic atrophy. Four weeks after motoneuron depletion, SNB dendritic lengths had not declined further in T-treated males (32% decreased), and were now 102% longer than those of untreated, saporin-injected males. These findings suggest that SNB dendrites undergo a protracted atrophy and subsequent recovery following partial motoneuron depletion, and that the neuroprotective effects of T attenuate the magnitude of the induced atrophy.

Related Products: CTB-SAP (Cat. #IT-14)

Neuroprotective effects of testosterone in two models of spinal motoneuron injury

Sengelaub DR, Osborne MC, Little CM, Huyck KD, Verhovshek T (2006) Neuroprotective effects of testosterone in two models of spinal motoneuron injury. Neuroscience 2006 Abstracts 683.12. Society for Neuroscience, Atlanta, GA.

Summary: Following induced death or axotomy of spinal motoneurons remaining motoneurons atrophy, but this atrophy can be reversed or prevented by treatment with testosterone (T). For example, partial depletion of motoneurons from the highly androgen-sensitive spinal nucleus of the bulbocavernosus (SNB) induces dendritic atrophy in remaining motoneurons, and this atrophy is prevented by treatment with T. To test whether T has similar effects in more typical motoneurons, we examined potential neuroprotective effects in motoneurons innervating muscles of the quadriceps. Motoneurons innervating the vastus medialis muscle were selectively killed by intramuscular injection of cholera toxin conjugated saporin. Simultaneously, some saporin-injected rats were given implants containing T or left untreated. Four weeks later, motoneurons innervating the ipsilateral vastus lateralis muscle were labeled with cholera toxin conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. Compared to intact control males, partial motoneuron depletion resulted in decreased dendritic length (70%) and soma size (13%) in remaining quadriceps motoneurons, but as in the SNB, this atrophy was attenuated by T treatment. In a second model, brain-derived neurotrophic factor (BDNF) and T have a combinatorial effect in the maintenance of motoneurons after axotomy in that dendritic morphology is supported by BDNF treatment, but only in the presence of T. Using immunohistochemical methods, we examined the regulation of the expression of the BDNF receptor, trkB, by T. In both the highly androgen-sensitive motoneurons of the SNB and the more typical quadriceps motoneurons, the expression of trkB receptors was regulated by the presence of T. Motoneurons of castrated animals deprived of T show reduced expression of trkB receptors compared to motoneurons of intact animals or castrated animals given T replacement. This finding suggests that maintenance of trkB receptors with T may be necessary to permit the trophic effects of BDNF in supporting dendritic morphology after axotomy. Together, these findings suggest that T regulates neuroprotective effects through a variety of mechanisms, not only in highly androgen-sensitive motoneurons, but in more typical motoneuron populations as well.

Related Products: CTB-SAP (Cat. #IT-14)

Testosterone treatment prevents deficits in motor activation caused by partial loss of motoneurons

Fargo KN, Sengelaub DR (2005) Testosterone treatment prevents deficits in motor activation caused by partial loss of motoneurons. Neuroscience 2005 Abstracts 672.8. Society for Neuroscience, Washington, DC.

Summary: In male rats, motoneurons of the spinal nucleus of the bulbocavernosus (SNB) project to the bulbocavernosus and levator ani muscles (BC/LA). The SNB system is dependent on androgens for its development, adult morphology, and function. We have previously demonstrated that unilateral depletion of SNB motoneurons induces atrophy of dendrites and somata in contralateral SNB motoneurons, and that this atrophy is prevented by treatment with exogenous testosterone. In the present experiment, we tested the hypothesis that this neuroprotective effect of testosterone on the morphology of SNB motoneurons is accompanied by a neuroprotective effect on the electrophysiological function of the system. We unilaterally depleted right-side SNB motoneurons by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, some of the saporin-injected rats were castrated and immediately given exogenous testosterone in subcutaneous Silastic capsules designed to produce testosterone titers in the high-normal physiological range. Four weeks later, animals were anesthetized and spinally transected. A stimulating electrode was placed on the left L6 dorsal root, which carries motor afferents from the BC/LA, and a recording electrode was placed on the motor branch of the left pudendal nerve, which carries SNB motoneuron axons to the BC/LA. Both nerves were then severed distal to electrode placement, and recruitment curves were generated by stimulating through the entire range of effective intensities. Consistent with our previously reported morphological changes, unilateral motoneuron depletion resulted in an attenuation of the recruitment of motoneurons in the contralateral SNB, and this was completely prevented by treatment with exogenous testosterone. This result provides a functional correlate to the neuroprotective effects of testosterone treatment on SNB morphology following unilateral motoneuron depletion, further supporting a role for testosterone as a neurotherapeutic agent in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Ablation of vagal preganglionic neurons innervating the extra-thoracic trachea affects ventilatory responses to hypercapnia and hypoxia.

Wu M, Kc P, Mack SO, Haxhiu MA (2006) Ablation of vagal preganglionic neurons innervating the extra-thoracic trachea affects ventilatory responses to hypercapnia and hypoxia. Respir Physiol Neurobiol 152(1):36-50. doi: 10.1016/j.resp.2005.07.002

Summary: Hypercapnia, an excess of CO2 in the blood, is thought to stimulate the release of acetylcholine by airway-related vagal preganglionic neurons (AVPNs). AVPNs in the nucleus ambiguus (NA) were lesioned with ten 1-µl injections of CTB-SAP (Cat. #IT-14) into the trachealis muscle of rats. Treated animals maintained rhythmic breathing patterns, but episodes of increased respiratory rate in response to hypercapnia were significantly reduced.

Related Products: CTB-SAP (Cat. #IT-14)

Molecular neurosurgery with targeted toxins

Wiley RG, Lappi DA (2005) Molecular neurosurgery with targeted toxins. Humana Press, Totowa, New Jersey.

Summary: The idea behind the book was to provide a road map for the users of Molecular Neurosurgery to see how experienced scientists used these exceptional reagents in their work. Experiments with several targeted toxins are described, and readers can get an idea either specifically about a targeted toxin that they’re using, or about how a type of molecule is used and at what dosage, in a paradigm similar to theirs.

Related Products: 192-IgG-SAP (Cat. #IT-01), ME20.4-SAP (Cat. #IT-15), Anti-DBH-SAP (Cat. #IT-03), SSP-SAP (Cat. #IT-11), Dermorphin-SAP / MOR-SAP (Cat. #IT-12), IB4-SAP (Cat. #IT-10), CTB-SAP (Cat. #IT-14)

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Prevention of depletion-induced motoneuron dendritic atrophy requires testosterone effects on target musculature

Fargo KN, Sengelaub DR (2004) Prevention of depletion-induced motoneuron dendritic atrophy requires testosterone effects on target musculature. Neuroscience 2004 Abstracts 310.10. Society for Neuroscience, San Diego, CA.

Summary: Motoneurons in the spinal nucleus of the bulbocavernosus (SNB) in male rats project to the penile muscles bulbocavernosus (BC) and levator ani (LA). These motoneurons share a midline location, have intermingled somata, extensive dendritic overlap, and common afferents, and organize coordinated contractions of the penile musculature. Unilateral depletion of BC-projecting motoneurons causes marked dendritic atrophy in contralateral BC-projecting motoneurons, and this atrophy can be prevented with testosterone (T) treatment. In this experiment, we test whether the depletion-induced atrophy is related to the innervation of homotypic muscles. BC-projecting motoneurons were depleted by unilateral injection with saporin conjugated to the cholera toxin B subunit (SAP); some animals were simultaneously treated with T. Four weeks later, a period demonstrated to be sufficient to observe dendritic atrophy in remaining motoneurons, HRP conjugated to the cholera toxin B subunit (BHRP) was injected into the ipsilateral LA. SAP injection into the BC muscle killed over 40% of ipsilateral SNB motoneurons. Dendritic length in LA-projecting motoneurons was reduced by almost 60%. Because the SAP-induced depletion of motoneurons and the resultant dendritic atrophy occurred across motor populations, this result indicates that the dendritic atrophy we have observed previously is not restricted to motoneurons projecting to homotypic muscles. In previous studies, prevention of dendritic atrophy by T treatment in BC-projecting motoneurons was accompanied by a marked hypertrophy of the BC muscle. In the present experiment, T treatment failed to prevent dendritic atrophy in LA-projecting motoneurons, and further did not result in hypertrophy of the LA ipsilateral to the SAP-injected BC. Thus, it appears the neuroprotective effect of T treatment on SNB motoneurons may be dependent on T effects in the target musculature.

Related Products: CTB-SAP (Cat. #IT-14)

Exogenous testosterone prevents motoneuron atrophy induced by contralateral motoneuron depletion.

Fargo KN, Sengelaub DR (2004) Exogenous testosterone prevents motoneuron atrophy induced by contralateral motoneuron depletion. J Neurobiol 60(3):348-359. doi: 10.1002/neu.20027

Summary: Gonadal steroids have been shown to supply a variety of neuroprotective and neurotherapeutic effects. Using 1-µl injections of 0.1% CTB-SAP (Cat. #IT-14) into the ipsalateral bulbocavernosus and the levator ani of rats, the authors examined the protective effects of testosterone on motoneuron morphology. After the lesion was induced some rats were castrated, and all animals were treated with exogenous testosterone. The results suggest that high-normal levels of testosterone can prevent motoneuron atrophy induced by contralateral motoneuron depletion.

Related Products: CTB-SAP (Cat. #IT-14)

Recurrent paraplegia after remyelination of the spinal cord.

Jasmin L, Ohara PT (2004) Recurrent paraplegia after remyelination of the spinal cord. J Neurosci Res 77(2):277-284. doi: 10.1002/jnr.20143

Summary: Previously, the authors demonstrated that a 3 µg-injection of CTB-SAP (Cat. #IT-14) into the lumbosacral intrathecal space caused a loss of motor function due to spinal demyelination. The motor function was recovered and stable for up to 9 months, after which the rats exhibited a slow deterioration of motor function, loss of spinal white matter, and the appearance of calcium deposits. The results indicate that the CTB-SAP-induced demyelination model is useful for investigating long term effects of axon and motoneuron loss.

Related Products: CTB-SAP (Cat. #IT-14)

Testosterone manipulation protects motoneurons from dendritic atrophy after contralateral motoneuron depletion.

Fargo KN, Sengelaub DR (2004) Testosterone manipulation protects motoneurons from dendritic atrophy after contralateral motoneuron depletion. J Comp Neurol 469(1):96-106. doi: 10.1002/cne.10991

Summary: The authors wished to investigate the therapeutic effects of testosterone on motoneuron dendrites in nerve injury models. 1 µl of a 0.1% solution of CTB-SAP (Cat. #IT-14) solution was unilaterally injected into the ispilateral bulbocavernosus and levator ani muscles of rats, and the contralateral motoneuron morphology was examined. In castrated rats receiving testosterone, dendrites in the spinal nucleus of the bulbocavernosus grew after CTB-SAP treatment. This is a demonstration of the neuroprotective/neurotherapeutic role of testosterone in the nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

A combinatorial network of evolutionarily conserved myelin basic protein regulatory sequences confers distinct glial-specific phenotypes.

Farhadi HF, Lepage P, Forghani R, Friedman HC, Orfali W, Jasmin L, Miller W, Hudson TJ, Peterson AC (2003) A combinatorial network of evolutionarily conserved myelin basic protein regulatory sequences confers distinct glial-specific phenotypes. J Neurosci 23(32):10214-10223. doi: 10.1523/JNEUROSCI.23-32-10214.2003

Summary: The authors used intrathecal injections of 0.3 µg CTB-SAP (Cat. #IT-14) to induce spinal cord demyelination for the purpose of defining the regulatory network controlling myelin basic protein transcription in mice.

Related Products: CTB-SAP (Cat. #IT-14)

Testosterone treatment protects motoneurons from dendritic atrophy following contralateral motoneuron depletion

Fargo KN, Sengelaub DR (2003) Testosterone treatment protects motoneurons from dendritic atrophy following contralateral motoneuron depletion. Neuroscience 2003 Abstracts 602.2. Society for Neuroscience, New Orleans, LA.

Summary: In male rats, motoneurons of the spinal nucleus of the bulbocavernosus (SNB) project to the bulbocavernosus and levator ani muscles. SNB motoneurons and their target muscles are dependent on testosterone (T). We have previously demonstrated that unilateral depletion of SNB motoneurons induces dendritic atrophy in contralateral SNB motoneurons, and this atrophy is prevented by androgen manipulation. In the previous study, males were castrated for 6 weeks, then given replacement T coincident with motoneuron depletion. Because castration results in SNB dendritic retraction, and T replacement causes SNB dendrites to regrow to normal length, it is possible that the regressive changes or the active regrowth are involved in the protective effect of T manipulation. Alternatively, it may be that the effect can be accounted for simply by the high-normal levels of T produced by hormone implants. In the present experiment we show that SNB motoneuron dendrites are protected from contralateral motoneuron depletion by exogenous T alone (i.e., with no delay between castration and T replacement). We unilaterally depleted SNB motoneurons in male rats by intramuscular injection of cholera toxin conjugated saporin. Simultaneously, some saporin-injected rats were castrated and immediately given implants containing T. Four weeks later, contralateral SNB motoneurons were labeled with cholera toxin conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. A group of intact control males was also used. Contralateral SNB motoneuron depletion induced dendritic retraction to about 40% of normal length, but this atrophy was completely prevented by T treatment. Thus, the protective effect of T on SNB motoneurons is not due to prior dendritic retraction or T-induced regrowth per se. Instead, the presence of high-normal levels of T prevents dendritic retraction induced by contralateral motoneuron depletion.

Related Products: CTB-SAP (Cat. #IT-14)

Cholera toxin B-saporin cytotoxicity is correlated with the extent of GM1 expression on the cell surface

Kohls MD, Lappi DA (2003) Cholera toxin B-saporin cytotoxicity is correlated with the extent of GM1 expression on the cell surface. Neuroscience 2003 Abstracts 325.16. Society for Neuroscience, New Orleans, LA.

Summary: Cholera toxin is composed of five B-subunits that mediate binding to the cell surface monosialoganglioside GM1, and one A-subunit that irreversibly activates adenylate cyclase. GM1 is found in high concentrations on astrocytes and the myelin of oligodendrocytes, as well as on many other cell types. A targeted toxin was developed consisting of the ribosome-inactivating protein saporin coupled to the B-subunit of cholera toxin (CTB) for the purpose of eliminating cells that express GM1. This targeted toxin (CTB-SAP) binds to cell-surface GM1 and the entire molecule is then internalized. Saporin separates from CTB and is released from the endosome to inactivate ribosomes. The cytoxicity of CTB-SAP in a cell-based in vitro assay can be inhibited by the addition of free CTB, indicating binding specificity. CTB-SAP has been tested on a variety of cell lines and the effectiveness of the targeted toxin correlates with the extent of GM1 cell surface expression as demonstrated by fluorescence-activated cell sorting (FACS) analysis. For example, using FACS analysis, RBL-2H3 cells exhibit an 88% shift when labeled with CTB-FITC. The ED50 of CTB-SAP in a cytoxicity assay on these cells is 380 fM, which corresponds to 9150 CTB-SAP molecules per cell. In comparison, HS294T cells produce a 48% shift in FACS, and the ED50 in the cytotoxicity assay is 5.5 pM. The correlation of surface GM1 number with ED50 indicates that the number of saporin molecules internalized is of primary importance in the process of cytotoxicity. CTB-SAP has been used to demyelinate the lumbar spinal cord (Jasmin et al.), eliminate sympathetic preganglionic neurons, and eliminate facial motoneurons in the rat (Llewellyn-Smith et al.). CTB-SAP is an effective and specific tool for the in vitro and in vivo elimination of cells that express GM1 on the cell surface.

Related Products: CTB-SAP (Cat. #IT-14)

Targeted toxins in pain.

Wiley RG, Lappi DA (2003) Targeted toxins in pain. Adv Drug Deliv Rev 55(8):1043-1054. doi: 10.1016/s0169-409x(03)00102-9

Summary: The authors discuss the use of 'molecular neurosurgery' in the study of nociception. Applications using targeted toxins, which include immunotoxins, protein-toxin conjugates, or peptide-toxin conjugates, are illustrated. The authors describe the use of these molecules as research tools, as well as their potential for therapeutics. A helpful table is included that lists neuronal surface markers and class of cells targeted for each targeted toxin. Reagents discussed: CTB-SAP (Cat. #IT-14), IB4-SAP (Cat. #IT-10), OX7-SAP (Cat. #IT-02), 192-Saporin (Cat. #IT-01), ME20.4-SAP (Cat. #IT-15), Anti-DBH-SAP (Cat. #IT-03), Anti-DAT-SAP (Cat. #IT-25), SP-SAP (Cat. #IT-07), Dermorphin-SAP (Cat. #IT-12), Orexin-SAP (Cat. #IT-20), CRF-SAP (Cat. #IT-13), and acetylated LDL-SAP (Cat. #IT-08).

Related Products: CTB-SAP (Cat. #IT-14), IB4-SAP (Cat. #IT-10), OX7-SAP (Cat. #IT-02), 192-IgG-SAP (Cat. #IT-01), ME20.4-SAP (Cat. #IT-15), Anti-DBH-SAP (Cat. #IT-03), Anti-DAT-SAP (Cat. #IT-25), SP-SAP (Cat. #IT-07), Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Orexin-B-SAP (Cat. #IT-20), CRF-SAP (Cat. #IT-13), Acetylated LDL-SAP (Cat. #IT-08)

Androgen manipulation protects remaining motoneurons from dendritic atrophy after induced motoneuron death.

Fargo KN, Sengelaub DR (2002) Androgen manipulation protects remaining motoneurons from dendritic atrophy after induced motoneuron death. Neuroscience 2002 Abstracts 466.13. Society for Neuroscience, Orlando, FL.

Summary: Androgen treatment facilitates axon regrowth after axotomy of facial and sciatic motoneurons, and reverses castration-induced dendritic atrophy in motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in rats. We assessed whether a similar therapeutic effect of androgen would be seen in dendrites following partial depletion of SNB motoneurons. We injected the toxin saporin, conjugated to choleratoxin (β-saporin), unilaterally into the SNB target muscles, bulbocavernosus (BC) and levator ani (LA), of two groups of adult male rats. One group had been castrated six weeks earlier to induce dendritic atrophy, and received testosterone-filled Silastic capsules coincident with β-saporin injection (SAP+T). The other group had no castration or androgen treatment (SAP-only). Four weeks after β-saporin injection, we injected choleratoxin conjugated HRP into the contralateral (non-saporin injected) BC muscle to label SNB motoneurons. A group of untreated normal males was also included. Cell counts were performed, and dendrites of HRP-labeled SNB motoneurons were reconstructed in three dimensions. β-saporin killed ~65% of motoneurons in the SNB ipsilateral to the saporin-injected muscles; contralateral SNB motoneuron numbers were not affected. SNB dendritic arbors on the non-saporin injected side were ~60% shorter in SAP-only animals compared to those of untreated males; in contrast, dendritic arbors in SAP+T animals were unaffected. These results indicate that a) motoneuron death causes dendritic atrophy in remaining SNB motoneurons, and that b) previous castration and concurrent testosterone replacement protects against this atrophy.

Related Products: CTB-SAP (Cat. #IT-14)

Schwann cells can enter the demyelinated spinal cord from dorsal roots via scar tissue.

Janni G, Jasmin L, Ohara PT (2001) Schwann cells can enter the demyelinated spinal cord from dorsal roots via scar tissue. Neuroscience 2001 Abstracts 157.4. Society for Neuroscience, San Diego, CA.

Summary: We have studied the routes of entry of Schwann cells into the demyelinated spinal cord. Following application of the toxin CTB-Sap (B fragment of Cholera toxin conjugated to Saporin) into the intrathecal space of adult rats there occurs massive loss of oligodendrocytes with secondary demyelination of the lumbar spinal cord with sparing of axons. Concurrent with the demyelination, an arachnoiditis develops that results in dorsal roots becoming adherent to the lateral spinal cord. Light and electron microscopy showed that Schwann cells in the dorsal roots were always separated from the demyelinated axons by a mesenchymal interface part of which was formed by the dorsal root perineurium. Within 15 days of the demyelination, Schwann cell precursors (p75 immunopositive) migrated from the dorsal roots into the spinal cord via the adhesions and were found to divide within the cord. Schwann cell myelination of demyelinated central axons was consistently observed by day 30. Therefore the Schwann precursors were able to migrate into demyelinated spinal cord through non-neuronal cellular barriers without being in direct contact with demyelinated axons. These findings suggest that, under appropriate conditions, Schwann cells might be introduced therapeutically into the demyelinated spinal cord via intrathecal application and avoid direct spinal injection.

Related Products: CTB-SAP (Cat. #IT-14)

Schwann cells are removed from the spinal cord after effecting recovery from paraplegia.

Jasmin L, Janni G, Moallem TM, Lappi DA, Ohara PT (2000) Schwann cells are removed from the spinal cord after effecting recovery from paraplegia. J Neurosci 20(24):9215-9223. doi: 10.1523/JNEUROSCI.20-24-09215.2000

Related Products: CTB-SAP (Cat. #IT-14)

Tracer-toxins: cholera toxin B-saporin as a model.

Llewellyn-Smith IJ, Martin CL, Arnolda LF, Minson JB (2000) Tracer-toxins: cholera toxin B-saporin as a model. J Neurosci Methods 103(1):83-90. doi: 10.1016/s0165-0270(00)00298-3

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Schwann cells are removed from the rat spinal cord after effecting recovery from paraplegia.

Janni G, Moallem T, Lappi DA, Ohara PT, Jasmin L (2000) Schwann cells are removed from the rat spinal cord after effecting recovery from paraplegia. Neuroscience 2000 Abstracts 516.8. Society for Neuroscience, New Orleans, LA.

Summary: Remyelination of the CNS is necessary to restore neural function in a number of demyelinating conditions such as multiple sclerosis. Schwann cells, the myelinating cells of the periphery, are good candidates for this purpose, having more robust regenerative properties than their central homologues, the oligodendrocytes. While the ability of Schwann cells to remyelinate the CNS and effect functional recovery has been demonstrated, their long term survival in the CNS after myelinating central axons is largely unknown. We use saporin conjugated to the cholera toxin B-subunit to demyelinate the rat lumbar spinal cord, remove macroglia, and produce paraplegia. This treatment is followed by a spontaneous proliferation of large numbers of endogenous Schwann cells which remyelinate spinal cord axons with concomitant functional recovery from paraplegia within 75 days. During the following weeks, however, quantification on thin sections shows that Schwann cells are progressively replaced by oligodendrocytes, without any lapse in behavioral recovery. This removal of Schwann cells is confirmed by ultrastructural examination and by immunocytochemistry for Schwann cells and oligodendrocytes. Our results indicate that Schwann cell remyelination of the spinal cord might not be permanent. They can be induced to demyelinate and desheath through endogenous mechanisms that remain to be characterized.

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CTB-saporin induced demyelinating myelopathy in the rat.

Janni G, Lappi DA, Ohara PT, Jasmin L (1999) CTB-saporin induced demyelinating myelopathy in the rat. Neuroscience 1999 Abstracts 731.2. Society for Neuroscience, Miami, FL.

Summary: In designing a rat model of demyelinating disease, we have used a newly developed neurotoxin, the B fragment of cholera toxin (CTB) linked to the potent ribosome inactivating protein saporin. Saporin linked to CTB targets cell expressing ganglioside GM1 on their surface, mainly Schwann cells, oligodendrocytes, and to a lesser degree neurons. After binding to GM1, CTB-Saporin is rapidly endocytosed and induces cell death. We demonstrate that intrathecal injection of 1 µg in 5 µl of CTB-Saporin at the lumbar level produces a demyelinating disease of the spinal cord. Behaviorally, this disease is characterized by an ascending paralysis that progresses most prominently from day 7 to day 14 post-treatment. In approximately half of the animals, the disease progresses to the brainstem, while in the others the disease regresses spontaneously, leaving these animals with only a moderate residual neurologic deficit. Histologically and ultrastructurally, the spinal pathology is characterized by a loss of myelin and oligodendroglyocytes as well as an immune response involving circulating leukocytes. Immunostaining shows the presence of CD8 immunopositive T lymphocytes but not CD4 T lymphocytes. We therefore conclude that CTB-Saporin induced demyelination involves an immune, but not an autoimmune mediated component in addition to the direct cytotoxic effect. Supported by Georgetown University.

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Retrogradely transported CTB-saporin kills sympathetic preganglionic neurons.

Llewellyn-Smith IJ, Martin CL, Arnolda LF, Minson JB (1999) Retrogradely transported CTB-saporin kills sympathetic preganglionic neurons. Neuroreport 10(2):307-312. doi: 10.1097/00001756-199902050-00019

Related Products: CTB-SAP (Cat. #IT-14)