Effects of combined treatment with trifluoperazine-HCl and amobarbital on punished behavior in rats

Amobarbital and certain low doses of trifluoperazine hydrochloride each attenuated the suppressant effects of punishment on response rates of rats in a multiple schedule of reinforcement containing punishment and non-punishment components. Combined treatment with these two agents, at a dose ratio of 1∶15 of trifluoperazine-HCl (base weight) to amobarbital, also attenuated the effects of punishment at all dose levels tested. The effect of the combined treatment was qualitatively similar to that seen following treatment with chlordiazepoxide. Combined treatment produced an effect on punished behavior at a dose level containing an ineffective dose of trifluoperazine-HCl and the degree of effect, at this dose level, was significantly greater than that produced by amobarbital alone, at this dose level. The effects of the combined treatment on non-punished responding were similar to those of trifluoperazine-HCl alone.