Muscarinic receptor-mediated induction of Fos protein in rat brain.
Recent studies have shown that the centrally active muscarinic agonist pilocarpine induces c-fos mRNA in rat cortex. Here we describe the localization of muscarinic receptor-induced FOS protein, within the rat central nervous system (CNS), following administration of pilocarpine (25 mg/kg). High levels of FOS induction were apparent in many forebrain structures including the primary olfactory (piriform) cortex, nucleus accumbens, amygdala, hippocampus, neocortex and supra-optic nucleus of the hypothalamus. Within the neocortex FOS induction followed a laminar distribution being highest in layers 4 and 6 with lower induction seen in layers 2 and 5. Other areas showing FOS induction included the striatum, septum, inferior colliculus, thalamus, hypothalamus and several brainstem nuclei. Both atropine (10 mg/kg) and pirenzepine (100 mg/kg) reduced FOS induction suggesting that a pirenzepine-sensitive muscarinic receptor was involved. The possible significance of muscarinic-mediated FOS induction, to cholinergic kindling and the cholinergic hypothesis of learning and memory, is discussed.
Hughes
P
P
Department of Pharmacology and Clinical Pharmacology, University of Auckland School of Medicine, New Zealand.
Dragunow
M
M
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016762:Genes, fos / Q000187:drug effects; D007150:Immunohistochemistry; D008297:Male; D009928:Organ Specificity; D010862:Pilocarpine / Q000494:pharmacology*; D010890:Pirenzepine / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*
D016760:Proto-Oncogene Proteins c-fos; D011976:Receptors, Muscarinic; D010862:Pilocarpine; D010890:Pirenzepine; D001285:Atropine