targeted-toxins

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)

Tait DS, Brown VJ (2008) Lesions of the basal forebrain impair reversal learning but not shifting of attentional set in rats. Behav Brain Res 187:100-108. doi: 10.1016/j.bbr.2007.08.035

Summary: The authors compared specific lesions of the basal forebrain using 192-IgG-SAP (Cat. #IT-01) with non-specific lesions generated by ibotenic acid. Rats were given 0.12 µg per 0.5 µl bilateral injections of 192-IgG-SAP. The treated animals were then tested in food reward tasks involving two-choice discriminations and reversal of stimulus-reward. Animals with specific lesions did not show impairment with any of the tasks suggesting that non-cholinergic neurons are involved in reversal learning. This work also demonstrates the similarities between monkey and rodent basal forebrain function.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Aztiria E, Cataudella T, Spampinato S, Leanza G (2009) Septal grafts restore cognitive abilities and amyloid precursor protein metabolism. Neurobiol Aging 30(10):1614-1625. doi: 10.1016/j.neurobiolaging.2007.12.018

Summary: Although cholinergic loss and the presence of ß-amyloid plaques are well documented in Alzheimer’s disease, it is unknown whether restoration of regulatory cholinergic inputs affects in vivo b-amyloid precursor protein (APP). 5 µg of 192-IgG-SAP (Cat. #IT-01) was split between the lateral ventricles of rats. 6 months post-surgery the animals were implanted with cholinergic-rich septal tissue grafts. Grafted animals exhibited normal or near-normal levels of APP. APP levels, as well as improved spatial navigation performance, correlated strongly with graft-induced cholinergic changes.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Rostron CL, Farquhar MJ, Latimer MP, Winn P (2008) The pedunculopontine tegmental nucleus and the nucleus basalis magnocellularis: do both have a role in sustained attention?. BMC Neurosci 9:16. doi: 10.1186/1471-2202-9-16

Summary: This study provided further investigation into the role of the pedunculopontine tegmental nucleus (PPTg) in control of sustained attention. Rats were given 0.13 µg injections of 192-IgG-SAP (Cat. #IT-01) into the nucleus basalis magnocellularis. The immunotoxin-treated animals were compared to animals receiving ibotenate injections into the PPTg. Results suggest that ibotenate lesions cause impaired selection of conditioned response as shown by an increase in unconditioned behaviors. 192-IgG-SAP treated animals exhibited difficulty obtaining successful lever presses linked to attention.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Kline IV RH, Wiley RG (2008) Spinal mu-opioid receptor-expressing dorsal horn neurons: role in nociception and morphine antinociception. J Neurosci 28:904-913. doi: 10.1523/JNEUROSCI.4452-07.2008

Summary: The authors used Dermorphin-SAP (Cat. #IT-12) to investigate the function of spinal cord mu-opioid receptor (MOR)-expressing dorsal horn neurons in nociception and morphine analgesia. Rats were treated with 500 ng intrathecal injections of Dermorphin-SAP; 500 ng of Blank-SAP (Cat. #IT-21), and up to 1 µg of Saporin (Cat. #PR-01) were used as controls. The data indicate that MOR-expressing dorsal horn neurons are necessary for morphine action and play a role in nocifensive responses to persistent pain in the formalin test.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Blank-SAP (Cat. #IT-21), Saporin (Cat. #PR-01)

Kaur S, Junek A, Black MA, Semba K (2008) Effects of ibotenate and 192IgG-saporin lesions of the nucleus basalis magnocellularis/substantia innominata on spontaneous sleep and wake states and on recovery sleep after sleep deprivation in rats. J Neurosci 28:491-504. doi: 10.1523/JNEUROSCI.1585-07.2008

Objective: To examine the role of this area of the brain in several facets of sleep behavior.

Summary: The results suggest that cholinergic neurons and non-cholinergic neurons in the basal forebrain play different, but important roles in non-rapid eye movement sleep and EEG delta power after sleep loss. Non-cholinergic basal forebrain neurons inhibit delta waves, whereas cholinergic neurons promote wakefulness.

Usage: The caudal basal forebrain of rats was lesioned with 0.26-µg bilateral injections of 192-IgG-SAP.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Q: I have a question about what solutions might be incompatible with the conjugated saporins. We have done an experiment where we injected a mixture of saporin conjugate (same batch we’ve used in previous studies here) and a cocktail of 5,7-dihydroxytryptamine and 6-hydroxydopamine (in 0.1% ascorbic acid) to try to deplete multiple neurotransmitters. 

The way we did this was to prepare both solutions at double strength and to mix them immediately before loading the syringe and placing the injections. So the final solution has 0.05% ascorbate, 0.01 mg/ml saporin conjugate, and I think 6 µg/µl 5,7-DHT and 4 mg/ml 6-OHDA.

Anyway, we are doing the histology now and the cholinergic lesion didn’t work. I’m wondering whether the ascorbic acid might have either damaged the conjugation of the saporin to the antibody, or have inactivated the saporin molecule itself somehow.

A: You have well-described what the problem is. A reducing agent will inactivate the toxin, and of course, ascorbic acid is a potent reducing agent. Because of your experience, we have added a line in the data sheet to caution people. This is the first report of this happening in nearly fourteen years of business, so it just had not been an issue.

Related: Targeted Toxins

Pang KCH, Jiao X, Servatius RJ (2008) Featured Article: Role of medial septal GABAergic neurons in learning and extinction: Effects of the novel GABA immunotoxin GAT1-SAP. Targeting Trends 9(1)

Related Products: GAT1-SAP (Cat. #IT-32)

Read the featured article in Targeting Trends.

Blanco-Centurion C, Gerashchenko D, Shiromani PJ (2007) Effects of saporin-induced lesions of three arousal populations on daily levels of sleep and wake. J Neurosci 27:14041-14048. doi: 10.1523/JNEUROSCI.3217-07.2007

Summary: Orexin neurons in the basal forebrain, tuberomammillary nucleus (TMN), and locus ceruleus (LC) are thought to regulate arousal. Rats were injected with two or three of the following targeted conjugates: anti-DBH-SAP (Cat. #IT-03), 0.25 µl bilateral injections of 1 µg/µl into the LC; orexin-SAP (Cat. #IT-20), 0.25 µl injection of 0.25 µg/µl into the TMN; 192-IgG-SAP (Cat. #IT-01), 3 µl injection of 2 µg/µl into the lateral ventricle. Small differences were observed in sleep architecture, but the data do not support the traditional hypothesis that these three areas of the brain are essential links in the control of wake levels.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Orexin-B-SAP (Cat. #IT-20), 192-IgG-SAP (Cat. #IT-01)

Berdiev RK, Chepurnov SA, Veening JG, Chepurnova NE, van Luijtelaar G (2007) The role of the nucleus basalis of Meynert and reticular thalamic nucleus in pathogenesis of genetically determined absence epilepsy in rats: A lesion study. Brain Res 1185:266-274. doi: 10.1016/j.brainres.2007.09.010

Summary: Absence seizures due to epilepsy usually occur during passive behavior. This work investigated the role of the cholinergic nucleus basalis of Meynert (NB) and the reticular thalamic nucleus (RT) in these seizures. Rats received either 75 ng of 192-IgG-SAP (Cat. #IT-01) or the control, mouse IgG-SAP (Cat. #IT-18), into the NB and the RT. Loss of cholinergic neurons in the NB resulted in an increased number of spike-and-wave discharges, a marker for absence seizures.

Related Products: 192-IgG-SAP (Cat. #IT-01), Mouse IgG-SAP (Cat. #IT-18)