Abstract
-Caerulein (CLN, 0.8-80 μg/kg, s.c.) was administered to male rats 10 min or 24 hr before the injection of SKF 38393 (3 mg/kg, i.p.). The increased mouth movement and grooming behavior by SKF 38393 were suppressed dose-dependently by CLN 10 min before the SKF 38393. CLN at the dose of 0.8 μg/kg, given 24 hr before the SKF 38393, suppressed the grooming behavior by SKF 38393. These findings suggest that a low dose of CLN, but not a high dose, had a delayed suppressive effect on the grooming behavior induced by an excess of D1-activity.