en Physiology Physiology Original Research: Basic Science in Medicine Original Research: Basic Science in Medicine The present work was performed to show the possible interaction of GAB A, and GABAB receptors in catalepsy. The following results were obtained: 1- Muscimol (MUS), a GABAA agonist, induced catalepsy. This effect was dose-dependent. Baclofen (BAC), a GABAB agonist, had no effect in this respect. 2- Catalepsy induced by muscimol was potentiated by pretreatment of animals with bicuculline (BIC), a GABAA antagonist, while pretreatment of animals with picrotoxin (PIC), another GABAA antagonist, did not change the response. 3- The cataleptogenic effect of a-flupenthixol (a-FPT), a neuroleptic which is a potent cataleptogenic drug, was also increased by bicuculline pretreatment. Aflupenthixol, in animals pretreated with picrotoxin, induced a small but significant increase in catalepsy. 4- Muscimol catalepsy may be due to GABA inhibitory effect of the drug upon dopaminergic function, while potentiation of cataleptogenic effect of a-flupenthixol or that of muscimol by bicuculline may be exerted through release of GABA from GABAergic nerve endings 179 182 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-631&slc_lang=en&sid=1 A SADEGHI-LOUYEH 20031947532846006172 20031947532846006172 Yes From the Department of Physiology Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran. Y SIMONIAN 20031947532846006173 20031947532846006173 No From the Department of Pharmacology, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.