Apomorphine anorexia: a behavioural and neuropharmacological analysis.

Anorectic effects of apomorphine were studied in a microstructural analysis paradigm. Low doses of apomorphine (less than 0.1 mg/kg SC) reduced food intake, by reducing both the rate of eating and eating time. The neuroleptics haloperidol and thioridazine blocked the effect of apomorphine on eating time, but not on eating rate. Anorectic effects elicited by apomorphine administration to the ventral tegmental area and, to a lesser extent, the substantia nigra were mediated by a selective reduction of eating time. Effects of apomorphine on eating time appear to result from an action at presynaptic dopamine receptors; the mechanism of the effect of apomorphine on eating rate is unclear.