Muscarinic agonist oxotremorine-M-induced long-term depression in rat cerebral cortex.
A long-lasting depression (LTD) of neuronal-evoked responses was induced in a dose-dependent fashion in neurons of rat sensorimotor cortex by a brief application of the muscarinic agonist oxotremorine-M. The depression was characterized as being of rapid onset (within 30 seconds), long duration (up to 40 minutes), and was evident for both glutamate- and acetylcholine-evoked discharges. Antagonism could be achieved by application of the nonspecific muscarinic antagonist atropine, and with the M2 antagonists gallamine or methoctramine. The M1 antagonist pirenzepine displayed only a weak effect. LTD could also be induced by the muscarinic agonists, oxotremorine and McN-A-343, but their potencies were lower than that of oxotremorine-M. Oxotremorine-M may be a useful tool for studies of long-term changes in synaptic efficacy.
Department of Physiology, Wayne State University, School of Medicine, Detroit, MI 48201.
Y
Y
Lin
J W
JW
Phillis
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000187:drug effects*; D005071:Evoked Potentials / Q000187:drug effects; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010095:Oxotremorine / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D005971:Glutamates; D018698:Glutamic Acid; D010095:Oxotremorine; D001285:Atropine; D000109:Acetylcholine