Induction of food intake by a noradrenergic system using clonidine and fusaric acid in the neonatal chick

To clarify noradrenergic systems on food intake of the neonatal chicks, we examined the effects of i.c.v injection of clonidine (CLON), an alpha(2)-re ceptor agonist, and fusaric (5-butylpicolinic) acid (FA), a dopamine (DA)-b eta-hydroxylase (DBH) inhibitor. Although a high dose (250 ng) of CLON indu ced a narcoleptic response and reduced food intake, food intake at 30 min p ost-injection was enhanced by lower doses (25 and 50 ng) of CLON. Central a dministration of FA (25, 50 and 100 mu g) increased food intake in a dose-d ependent fashion. It is suggested that feeding behavior is stimulated by lo w levels of CLON and decreased by further production of norepinephrine (NE) , and FA may play the disturbance of sleeping and then enhance food intake. (C) 1999 Elsevier Science B.V. All rights reserved.