EFFECTS OF THE 5-HT1A AGONIST 8-OH-DPAT ON OPERANT FEEDING IN PIGS

The effect of intravenous (IV) injection of 8-OH-DPAT on operant food intake in pigs has been examined in animals with food available ad lib and in pigs feeding after 4 h deprivation of food. Operant methods we re used to ascertain whether any increases in food intake were due to increased motivation to feed rather than stereotypic chewing movements . In nondeprived animals IV injection of 8-OH-DPAT at doses of 10, 30, and 50 mu g/kg significantly increased food intake in the 45 min foll owing injection. In pigs feeding after 4 h deprivation, IV injection o f 8-OH-DPAT at doses of 30 and 50 mu g/kg, given 5 min before feeding commenced, had no effect on food intake.