Printed in U.S.A. MODIFICATION OF THE EFFECTS OF CHLORPRO- MAZINE ON BEHAVIOR IN THE CHIMPANZEE’

BYRD, LARRY D.: Modification of the effects of chlorpromazine on behavior in the cimimpaimzee. J. Plmarnmacoi. Exp. Ther. 189: 24-32, 1974. During daily two-hour sessions, key-pressing behavior in the chimpanzee was nmaimm-taimmed ummder a multiple schedule comprising a 10-minute fixed-interval schedule and a 30-response fixed-ratio scimedule of food delivery. Water was freely available in the chimpanzee’s living area and in time experimental clmamber, and schedule-related drink-ing occurred regularly duriimg time session. Chlorpromazine had dose-dependent effects oim key pressing and oim water intake during time session. The drug increased mean re-spoimse rates umimder time fixed-iimterval scimeclule at doses of 0.03 to 0.3 mg/kg i.m. and decreased respommchng at 1.0 to 3.0 mg/kg. Time higim rates of responding engenmderedl unimder time fixed-ratio scimedumle were not affected by time lower doses, but were decreased by doses of 1.0 to 3.0 nmg/kg. Water imtake was also unaffected by doses below 1.0 nmmg/kg, bunt dlecreasddl at closes of 1.0 to 3.0 mg/kg. Presentation of a brief (20 msec) auditory stimulus after eacim response cluiring time fixed-interval and fixed-ratio scimed