RELATION OF CHLORPROMAZINE-EVOKED HYPOTHERMIA TO DISRUPTION OF CONDITIONED AVOIDANCE-ESCAPE BEHAVIOR

¹ College of Pharmacy, The Ohio State University, Columbus, Ohio

Doses of 1.0, 2.1, 4.1 and 8.2 mg/kg of chlorpromazine (CPZ) were administered to albino rats performing on a discrete conditioned avoidance-escape (CAR) schedule while peritoneal and hypothalamic temperatures were monitored continuously. At an environmental temperature of 24°C, CPZ produced hypothermia and disruption of CAR responding. Comparison of effect-duration curves for hypothermia and behavioral deficit revealed a superficial similarity. However, behavioral deficit reached high magnitudes sooner than hypothermia and was maintained longer. In a 31°C environment CPZ also disrupted CAR behavior but the thermal response was an increase rather than a decrease in temperature. As at 24°C, there was a superficial similarity between the thermal and behavioral effects, but behavioral deficit preceded maximum temperature change. Although CPZ produced opposing temperature changes at 24 and 31°C, the degree of behavioral deficit at the two environmental temperatures was similar. It is concluded that CPZ-induced hypothermia does not greatly influence the CAR-disrupting effect of this drug. The converse possibility, i.e., that disruption of behavior may influence the thermal response to CPZ, is considered.