Clozapine injected into the nucleus accumbens potentiates apomorphine-induced jaw movements.
The effects of clozapine injected into the nucleus accumbens on apomorphine-induced jaw movements were studied. Jaw movements induced by apomorphine (0.5 mg/kg i.v.) were potentiated by clozapine (10 micrograms/0.2 microliters) injected into the nucleus accumbens 10 min before apomorphine. Enhancement of the apomorphine-induced jaw movements was also found with the muscarinic acetylcholine receptor antagonist, methylscopolamine (2.5 micrograms), whereas the acetylcholine receptor agonist, carbachol (2.5 micrograms), inhibited the effects of apomorphine. Injection of a smaller dose of carbachol (0.1 microgram) alone into the nucleus accumbens 10 min before failed to alter the effects of apomorphine but prevented the potentiation induced by clozapine. Both the 5-hydroxytryptamine(5-HT)2A receptor antagonist, 2-(2-dimethylaminoethylthio)-3-phenylquinoline hydrochloride (ICI 169,369, 0.1 and 0.2 microgram), and the alpha 1-adrenoceptor antagonist, prazosin (0.05 and 0.2 microgram), failed to affect the effects of apomorphine(0.5 mg/kg i.v.). In contrast, clozapine (1, 5 and 10 micrograms), ICI 169,369 (0.1 and 0.2 microgram) or prazosin (0.05 and 0.2 microgram) given into the ventral striatum inhibited the effects of apomorphine (0.5 mg/kg i.v.). It is suggested that the clozapine-induced potentiation in the nucleus accumbens might be due to its antimuscarinic properties.
de Beltrán
K K
KK
Department of Pharmacology, Nihon University School of Dentistry, Tokyo, Japan.
Koshikawa
N
N
Miwa
Y
Y
Kobayashi
M
M
Cools
A R
AR
D000704:Analysis of Variance; D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology*; D002217:Carbachol / Q000494:pharmacology; D003024:Clozapine / Q000008:administration & dosage / Q000494:pharmacology*; D004347:Drug Interactions; D007275:Injections, Intravenous; D007568:Jaw / Q000187:drug effects* / Q000502:physiology; D008297:Male; D018727:Muscarinic Antagonists; D019832:N-Methylscopolamine; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D010276:Parasympatholytics / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000378:metabolism; D012602:Scopolamine Derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology
D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D011804:Quinolines; D011976:Receptors, Muscarinic; D012602:Scopolamine Derivatives; D012702:Serotonin Antagonists; C054363:2-((2-(dimethylamino)ethyl)thio)-3-phenylquinoline; D002217:Carbachol; D003024:Clozapine; D001058:Apomorphine; D019832:N-Methylscopolamine; D011224:Prazosin