EFFECTS OF D-AMPHETAMINE, DIAZEPAM AND BUSPIRONE ON SCHEDULE-INDUCED-POLYDIPSIA SUPPRESSED BY RESPONSE-DEPENDENT AND RESPONSE-INDEPENDENT SHOCK

Food deprived Wistar rats were exposed to a fixed time 60 s food sched ule until they developed schedule-induced polydipsia. Rats were matche d in pairs according to their licking rate, being designated experimen tal or yoked control at random. Every fifth lick by experimental rats was then followed by an electric shock (0.05, 0.1, or 0.2 mA) while th e food schedule continued in operation. Yoked-control rats received th e same shocks as experimental rats, but independently of their own lic king. Drugs were then tested on the suppressed rates of licking. Diaze pam (0.5 2.0 mg/kg) increased punished schedule-induced polydipsia, a result not observed in yoked controls. No increases in the licks per m inute of experimental or control animals were found after d-amphetamin e (0.25 4.0 mg/kg) or buspirone (0.5 8.0 mg/kg). In comparison with pr evious results it is concluded that the antipunishment effects of drug s on schedule-induced behaviour depend on the type of punishment conti ngency. (C) Rapid Science Ltd.