Foltin R W
New York State Psychiatric Institute and Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, USA.
Alcohol. 1998 Oct;16(3):183-8. doi: 10.1016/s0741-8329(97)00171-7.
During daily 23-h sessions, baboons had concurrent access to food pellets and an oral ethanol/dextrose solution. The effect of increasing the fixed-ratio or "cost" for pellets on pellet and fluid intake was examined when baboons had access to 2%, 4%, or 8% (w/v) ethanol. Increasing the response requirement for a pellet decreased pellet intake. The rate of decrease in pellet intake with increasing pellet cost was unaffected by the availability of ethanol solutions, which were either self-administered or given in investigator-planned doses. Increasing the response cost for pellets significantly increased self-administration of 4% ethanol. The effect of increasing the cost for fluid on fluid and pellet intake was examined when baboons had access to vehicle, 4% or 8% (w/v) ethanol. Although the total daily number of fluid deliveries was significantly greater when 4% ethanol was available, compared to vehicle, increasing the cost for a fluid delivery to 32 responses and above decreased intake of all three fluids similarly. Increasing the cost of ethanol did not affect food intake.
