The effects of p-chlorophenylalanine, a depletor of brain serotonin, on behavior: I. facilitation of discrimination learning

Abstract

Rats were given either position discrimination and discrimination reversal, simultaneous brightness discrimination, or successive brightness discrimination tasks. Half of the subjects were injected with p-chlorophenylalanine (p-CIPhe) in Steroid Suspension Vehicle and half were injected with the vehicle only. Rats given p-CIPhe learned the two brightness discriminations with fewer errors than the control animals. No differences were found between groups given the position discrimination and discrimination reversal task. Since p-CIPhe severely depletes brain serotonin with only a slight reduction of brain catechol amines, it is likely that reduction of brain serotonin was responsible for the facilitation of learning found in previous experiments where both serotonin and catechol amines were reduced.