Pimozide attenuates acquisition of lever-pressing for food in rats.

Pimozide pretreatment produced a dose-dependent attenuation of acquisition of a lever-pressing habit motivated by food reward in hungry rats. No evidence of learning was seen in animals treated at 1.0 mg/kg, minimal learning was seen at 0.5 mg/kg, and retarded learning which ultimately did reach normal asymptote was seen at 0.25 mg/kg. Thus primozide attenuates the response acquisition function as well as the previously studied response maintenance function of food reward.