The effects of p-chlorophenylalanine, a depletor of brain serotonin, on behavior: II. Retardation of passive avoidance learning

Abstract

Rats were tested for passive avoidance learning following injection of p-chlorophenylalanine in Steroid Suspending Vehicle, or the vehicle only. In Exp. 1, the subjects were trained for 20 trials before testing; in Exp. 2, the subjects were trained to a criterion before testing. In both experiments, subjects given p-ClPhe learned more slowly than controls. This supported the hypothesis that p-ClPhe, a specific depletor of brain serotonin, reduces emotionality rather than increases learning ability.