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.
Takakura AC, Barna BF, Cruz JC, Colombari E, Moreira TS (2014) Phox2b-expressing retrotrapezoid neurons and the integration of central and peripheral chemosensory control of breathing in conscious rats. Exp Physiol 99(3):571-585. doi: 10.1113/expphysiol.2013.076752
Summary: Previous work has shown that lesions to the retrotrapezoid nucleus (RTN) have at least a modest effect on breathing, but it is unclear whether those lesions affected the entire nucleus or were incomplete. The authors used bilateral lesions of the RTN with 0.3 to 1.2 ng total of SSP-SAP (Cat. #IT-11) to eliminate neurokinin-1 receptor-expressing neurons; these are also Phox2b+TH- neurons. The results indicate that loss of Phox2b(+)TH(-) neurons may cause deficits seen after RTN lesion, and help define the ways in which these cells are involved in controlling central and peripheral chemoreflexes.
Freiria-Oliveira AH, Blanch GT, De Paula PM, Menani JV, Colombari DS (2013) Lesion of the commissural nucleus of the solitary tract/A2 noradrenergic neurons facilitates the activation of angiotensinergic mechanisms in response to hemorrhage. Neuroscience 254:196-204. doi: 10.1016/j.neuroscience.2013.09.017
Summary: Previous work has generated conflicting data on the role of catecholaminergic A2 neurons in the nucleus of the solitary tract (NTS) in control of arterial pressure lability. The authors used Anti-DBH-SAP (Cat. #IT-03) to lesion these neurons in a hypotensive hemorrhage model. Rats received two injections of 12.6 ng into the commissural NTS. Mouse IgG-SAP (Cat. #IT-18) was used as a control. The lesioned animals quickly recovered from hypotension, but were impaired by the icv administration of losartan.
Summary: Although mainly known for their involvement in the control of arterial pressure, C1 neurons are also suspected to participate in numerous other physiological processes such as neuroendocrine response, glucose homeostasis, food consumption, and others. This review discusses the role of these neurons as ’emergency medical technicians’ – cells that produce and modulate physiological survival responses to acute physical stress. The use of Anti-DBH-SAP (Cat. #IT-03) to delineate C1 neurons in the rostral ventrolateral aspect of the medulla oblongata is discussed.
Grupe M, Paolone G, Jensen AA, Sandager-Nielsen K, Sarter M, Grunnet M (2013) Selective potentiation of (alpha4)3(beta2)2 nicotinic acetylcholine receptors augments amplitudes of prefrontal acetylcholine- and nicotine-evoked glutamatergic transients in rats. Biochem Pharmacol 86(10):1487-1496. doi: 10.1016/j.bcp.2013.09.005
Summary: Nicotinic acetylcholine receptors (nAChR) are involved in a wide range of processes in the central nervous system, many having to do with higher cognitive functions. In order to better understand how these receptors mediate attentional performance, the authors investigated glutamate release under varying conditions. In one series of experiments rats received a 160-ng injection of 192-IgG-SAP (Cat. #IT-01) into the right medial prefrontal cortex. The resulting decrease in glutamate release after the cholinergic lesion adds to the data indicating that positive modulation of nAChR may help alleviate attentional impairments caused by some brain disorders.
Romano A, Potes CS, Tempesta B, Cassano T, Cuomo V, Lutz T, Gaetani S (2013) Hindbrain noradrenergic input to the hypothalamic PVN mediates the activation of oxytocinergic neurons induced by the satiety factor oleoylethanolamide. Am J Physiol Endocrinol Metab 305(10):E1266-73. doi: 10.1152/ajpendo.00411.2013
Summary: Feeding behavior and energy balance are in part controlled by signals from the gut. Oleoylethanolamide (OEA) is an acylethanolamide that is thought to play a role in this network. Since peripheral administration of OEA has effects on the nucleus of the solitary tract (NTS) and paraventricular nucleus (PVN) the authors investigated the role of noradrenergic afferent input to these areas. Rats received bilateral 84-ng injections of Anti-DBH-SAP (Cat. #IT-03) into the PVN. Mouse IgG-SAP (Cat. #IT-18) was used as a control.
