Effects of triazolam on conditioned behavior in rats

Abstract

Effects of triazolam on various types of conditioned behavior were investigated and compared mainly with diazepam in rats. The active conditioned avoidance response of the rat in a Shuttle box was inhibited by triazolam and diazepam only at large doses. The passive avoidance response in a step-down method was not affected by either triazolam or diazepam, but was markedly suppressed by chlorpromazine. The low rate response of hypothalamic self-stimulation behavior was markedly increased by triazolam at doses ranging from 2 to 40 mg/kg p.o., but was suppressed at doses over 80 mg/kg p.o. The high rate response was unaffected by triazolam even at doses of 40~ 180 mg/kg p.o. The low rate response was increased by diazepam at doses of 1~ 10 mg/kg p.o. and was suppressed at 80 mg/kg p.o. The high rate response was reduced by diazepam at 180 mg/kg p.o. In the conflict situation of the rat subjected to food reward and foot-shock punishment, the lever press response in the unpunished period was reduced by triazolam at doses of 1~5 mg/ kg p.o., whereas that in the punished period was markedly increased. Similar effects were observed with diazepam at doses of 15~20 mg/kg p.o. Triazolam appeared to be 10~15 times more potent than diazepam in this anticonflict effect. Thus, triazolam appears to be a potent antianxiety agent. © 1978, The Japanese Pharmacological Society. All rights reserved.