Denervation supersensitivity in the cholinergic septo-hippocampal pathway: a microiontophoretic study.
Abstract
The purpose of this study was to determine whether denervation supersensitivity could be produced in an identified cholinergic pathway in the CNS of the rat. The mechanism for the development of this phenomenon was also explored. Cholinergic denervation of the hippocampus was accomplished by lesions of the medial septum. The response of hippocampal pyramidal cells to microiontophoretic application of acetylcholine (ACh) and carbachol in lesioned and unlesioned animals was determined by extracellular recording. There was a marked increase (6 X) in sensitivity to ACh 2-43 days following lesions. However, there was no increase in sensitivity to carbachol or glutamate. Other workers have shown that septal lesions cause a large decrease in hippocampal acetylcholinesterase (AChE) which is located mainly presynaptically. The absence of increase in sensitivity to carbachol, a cholinomimetic resistant to hydrolysis by AChE, suggests that the postlesion increase in sensitivity to ACh results from a decrease in its inactivation by AChE. A time course for the development of ACh supersensitivity was found to be similar to the time course of AChE loss previosly reported. Experiments using physostigmine, an AChE inhibitor, demonstrated that i...Continue Reading
References
Citations
Failure of chronic lithium treatment to block tricyclic antidepressant-induced 5-HT supersensitivity
Potentiation of responses to monoamines by antidepressants after destruction of monoamine afferents.
Related Concepts
Related Feeds
Basal Forebrain- Circuits
Basal forebrain is a region in the brain important for production of acetylcholine and is the major cholinergic output of the CNS. Discover the latest research on circuits in the basal forebrain here.