EFFECT OF TIAPRIDE, A D-2 SELECTIVE ANTAGONIST, ON CATALEPSY BEHAVIORIN MICE

The induction of catalepsy has been linked mainly to blockade of centr al dopamine D-2-receptors. Tiapride is a benzamide with a specific ant agonism of D, receptors and without affinity for other receptors. In t his study, the effect of tiapride (175, 225, 275 or 325 mg kg(-1), i.p ) on catalepsy behaviour in male and female mice was evaluated. Catale psy was measured by means of the bar test. An aluminium bar of 5 mm in diameter was placed 4 cm above the floor. Animals' forepaws were gent ly put on the bar and the time it took the animal to place at least on e paw on the floor was measured. If 1 min elapsed without movement, th e test was interrupted. Successive behavioural evaluations of cataleps y were carried out 30, 60 and 120 min after the administration of tiap ride or saline. Catalepsy was significantly increased in male and fema le mice treated with tiapride (in all doses examined). Moreover, there was a clear gender difference: female mice showed significantly more catalepsy than male mice after tiapride administration.