title: Effects of striatal injections of 8-bromo-cyclic-AMP on pilocarpine-induced tremulous jaw movements in rats.
abstract: Previous work has suggested that muscarinic agonist-induced jaw movements in rats were related to stimulation of M4 receptors, and that these movements could be suppressed by a full D1 agonist. In view of the involvement of cyclic-adenosine monophosphate (c-AMP) mechanisms in the response to stimulation of these two receptors, the present study investigated the effects of 8-bromo-c-AMP, which is a cell permeable analogue of c-AMP. In the first experiment, it was shown that local infusion of 8-bromo-c-AMP directly into ventrolateral striatum (VLS) was able to suppress the jaw movements induced by pilocarpine. The suppressive effects of 8-bromo-c-AMP occurred within a dose range of 5.0-10.0 microg. Injections of the highest dose of 8-bromo-c-AMP (10.0 microg) directly into the neocortex overlying the VLS had no significant effects on pilocarpine-induced jaw movements. These data demonstrate that mimicking the effects of c-AMP by administration of 8-bromo-c-AMP can suppress cholinomimetic-induced jaw movements. In addition, the present results suggest that one manifestation of the acetylcholine/dopamine interaction in striatum is that M4 and D1 receptors may interact to regulate c-AMP production.
authors.affiliation: Department of Psychology, University of Connecticut, Storrs, CT, 06269-1020, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Mayorga
authors.forename: G
authors.initials: G
authors.lastname: Gianutsos
authors.forename: J D
authors.initials: JD
authors.lastname: Salamone
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects*; D007568:Jaw; D008297:Male; D008845:Microinjections; D009068:Movement / Q000187:drug effects*; D018721:Muscarinic Agonists / Q000494:pharmacology*; D010862:Pilocarpine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018721:Muscarinic Agonists; D010862:Pilocarpine; D015124:8-Bromo Cyclic Adenosine Monophosphate