Effects of acute and chronic administration of caffeine on schedule dependent and schedule induced behavior.

The effects of caffeine (3.125, 6.25, 12.5, 25, 50, and 100 mg/kg) on lever pressing, schedule induced licking and water consumption induced by a fixed interval 1 min schedule were studied. Changes in these dependent variables were assessed when animals were reduced to 80% of their initial body weight by partial food deprivation and when body weights recovered after the animals were returned to conditions of ad lib feeding. Results indicate differential effects of the drug between animals at 80% body weight and when they are permitted to recover. Tolerance was examined for a single large dose only for the same dependent variables in animals at 80% body weight.