Ye Y, Bae S, Viet CT, Troob S, Bernabe D, Schmidt BL (2014) IB4(+) and TRPV1(+) sensory neurons mediate pain but not proliferation in a mouse model of squamous cell carcinoma. Behav Brain Funct 10(1):5. doi: 10.1186/1744-9081-10-5
Objective: To evaluate subtypes of sensory neurons involved in cancer pain and proliferation.
Summary: IB4(+) neurons play an important role in cancer-induced mechanical allodynia, while TRPV1 mediates cancer-induced thermal hyperalgesia. Characterization of the sensory fiber subtypes responsible for cancer pain could lead to the development of targeted therapeutics.
Usage: IB4(+) neurons play an important role in cancer-induced mechanical allodynia, while TRPV1 mediates cancer-induced thermal hyperalgesia. Characterization of the sensory fiber subtypes responsible for cancer pain could lead to the development of targeted therapeutics.
Ljubojevic V, Luu P, De Rosa E (2014) Cholinergic contributions to supramodal attentional processes in rats. J Neurosci 34(6):2264-2275. doi: 10.1523/JNEUROSCI.1024-13.2014
Summary: Previous work has shown that cholinergic transmission is important for attentional processing of visual stimuli. It is not known whether the role of the cholinergic system is specifically in visual processing, or if it is involved in all types of attentional processing. The authors administrated bilateral 40 ng injections of 192-IgG-SAP (Cat. #IT-01) to the nucleus basalis magnocellularis of rats. Animals had been previously trained on both visual and olfactory 5-choice serial reaction time tasks. Lesioned animals displayed deficits on both the visual and olfactory tasks when the attentional demand of the task was increased. The data suggest a modular cortical network that services both visual and olfactory attentional processes.
Hartig W, Saul A, Kacza J, Grosche J, Goldhammer S, Michalski D, Wirths O (2014) Immunolesion-induced loss of cholinergic projection neurones promotes beta-amyloidosis and tau hyperphosphorylation in the hippocampus of triple-transgenic mice. Neuropathol Appl Neurobiol 40(2):106-120. doi: 10.1111/nan.12050
Summary: 3xTg transgenic mice were treated with 2 μg of mu p75-SAP (Cat. #IT-16) into the right lateral ventricle to eliminate cholinergic neurons in the basal forebrain. These mice already have age-dependent β-amyloidosis and tau hyperphosphorylation. This new model supplies a potential framework in which to study the entire pathology of Alzheimer’s disease.
Tai SK, Ma J, Leung LS (2014) Medial septal cholinergic neurons modulate isoflurane anesthesia. Anesthesiology 120(2):392-402. doi: 10.1097/ALN.0b013e3182a7cab6
Summary: General anesthesia is associated with a decrease in cholinergic function. This work examines the effect of volatile anesthetics such as isoflurane or ketamine in the context of cholinergic depletion. Rats received 105-ng bilateral injections of 192-IgG-SAP (Cat. #IT-01) into the medial septum. Anesthetic effects were evaluated using a loss of righting reflex test. There was no difference between lesioned and control groups in the response to ketamine. When treated with isoflurane, lesioned animals were affected for longer periods of time, and hippocampal response was reduced. The results suggest a role for septal cholinergic neurons in the sensitivity to isoflurane.
Suto T, Severino AL, Eisenach JC, Hayashida KI (2014) Gabapentin increases extracellular glutamatergic level in the locus coeruleus via astroglial glutamate transporter-dependent mechanisms. Neuropharmacology 81C:95-100. doi: 10.1016/j.neuropharm.2014.01.040
Summary: Gabapentin is effective in reducing acute and chronic pain, but the mechanisms by which it works are not well understood. The authors assessed extracellular glutamate levels and glutamate interaction with several different cellular membrane proteins. Rats received a 0.25 μg injection of anti-DBH-SAP (Cat. #IT-03) into the locus coeruleus (LC) in order to deplete noradreline levels. Mouse IgG-SAP (Cat. #IT-18) was used as a control. The gabapentin-induced glutamate increase in the LC was not affected by the lesion, supporting data indicating that gabapentin induces glutamate release from astrocytes to stimulate descending inhibition.
Laursen B, Mork A, Plath N, Kristiansen U, Frank Bastlund J (2014) Impaired hippocampal acetylcholine release parallels spatial memory deficits in Tg2576 mice subjected to basal forebrain cholinergic degeneration. Brain Res 1543:253-262. doi: 10.1016/j.brainres.2013.10.055
Summary: The Tg2576 mouse strain provides a limited model for Alzheimer’s disease because they do not display degeneration of cholinergic neurons in the basal forebrain – the other main hallmark of Alzheimer’s disease in humans. Using 0.9 μg icv injections of mu p75-SAP (Cat. #IT-16) the authors evaluated mice that had both Aβ deposition and cholinergic depletion. The data show that these mice display cognitive decline and compromised cholinergic levels, creating a viable model for Alzheimer’s disease.
Lee LC, Rajkumar R, Dawe GS (2014) Selective lesioning of nucleus incertus with corticotropin releasing factor-saporin conjugate. Brain Res 1543:179-190. doi: 10.1016/j.brainres.2013.11.021 PMID: 24287211
Objective: To investigate the role of Nucleus Incertus (NI) neurons in behavior by lesioning these neurons in rats using CRF-SAP (IT-13).
Summary: NI neurons are integral to CRF1, Relaxin-3, and GABA signaling pathways. By targeting the NI region with CRF-SAP, these neurons are selectively eliminated, allowing for the study of Relaxin-3’s influence on mood and behavior. Given the NI neurons’ involvement in emotional regulation, this approach sheds light on their contribution to mental illness and psychiatric disorders.
Usage: Infusion of 172 ng of CRF–SAP (IT-13) into the NI of rats. Blank-SAP (Cat. #IT-21) was used as a control.
Roland JJ, Stewart AL, Janke KL, Gielow MR, Kostek JA, Savage LM, Servatius RJ, Pang KC (2014) Medial septum-diagonal band of Broca (MSDB) GABAergic regulation of hippocampal acetylcholine efflux is dependent on cognitive demands. J Neurosci 34(2):506-514. doi: 10.1523/JNEUROSCI.2352-13.2014
Summary: GABAergic and cholinergic neurons in the medial septum-diagonal band of Broca (MSDB) are both involved with spatial memory. In order to better understand the relationship between these two neuronal populations the authors administered 552.5 ng of GAT-1-SAP (Cat. #IT-32) to the MSDB of rats in several injections. Using a combination of behavioral assays and in vivo microdialysis it was shown that GAT-1-SAP lesions impaired hippocampal acetylcholine efflux as well as performance in the non-matching to position with delay test. The data indicate that GABAergic MSDB neurons are important during high memory load conditions.
Q: How long does it take to see the cell death occurring from the use of targeted toxins using saporin? Is there a time course of hours or days?
A: The figure below illustrates the time course of cell death very effectively. Internalization and cytotoxicity of SP-SAP in primary cultures of neonatal spinal cord neurons. Confocal image of neurons where the Substance P receptor; NK1R (SPR) immunofluorescence (A, C, D) appears red, areas of concentrated SPR immunofluorescence appear yellow. (A, C, and D) SPR immunofluorescence in neurons 2 hours, 1 day, and 4 days, respectively, after treatment with SP-SAP. (B) Confocal image showing SAP immunofluorescence (yellow) 2 hours after SP-SAP treatment.
These images were projected from 14 optical sections acquired at 0.8-mm intervals with a 603 lens. Bar, 25 mm.
It is recommended that you wait for two weeks to allow for all debris to be cleared and the animal to regain normal eating and sleeping habits.
Weisshaar CL, Winkelstein BA (2014) Ablating spinal NK1-bearing neurons eliminates the development of pain and reduces spinal neuronal hyperexcitability and inflammation from mechanical joint injury in the rat. J Pain 15(4):378-386. doi: 10.1016/j.jpain.2013.12.003
Summary: A high percentage of chronic neck pain involves the facet joint. Although the facet joint is innvervated by peptide-responsive nociceptive afferents, the role of these cells in the development and modulation of nociceptive signaling remains unclear. Using a previously developed rat model of facet joint injury, the authors examined the role of neurokinin-1 receptor-expressing spinal cells in this pathway. Rats received 100 ng SSP-SAP (Cat. #IT-11) via lumbar puncture. Blank-SAP (Cat. #IT-21) was used as a control. The results demonstrate that spinal NK1r-expressing cells are essential for nociception and inflammation due to a mechanical joint injury.
