Effects of carbon disulfide and FLA-63 on operant behavior in pigeons.

Carbon disulfide (CS2) and FLA-63 [bis(4-methyl-1-homopiperazinylthiocarbonyl)disulfide] were studied in pigeons working on a differential-reinforcement-of low-rates or a multiple fixed-interval fixed-ratio schedule of food reinforcement. Response rate on both schedules decreased after 8-hour exposures to CS2 (2 mg/1) of administration of FLA-63 (40 and 80 mg/kg). The effects of two successive 8-hour exposures to CS2 were cumulative and ten successive 4-hour exposures produced changes in differential-reinforcement-of-low-rates performance resembling those following acute exposure. Fixed-interval performance was disrupted by exposures to CS2 and doses of FLA-63 that left fixed-ratio performance intact.