This study was designed to examine the effects of intracerebroventricular (ICV) injection of bicuculline (GABA(A) receptor antagonist) and muscimol (GABA(A) receptor agonist) on glutamate-induced eating response in 24-h food-deprived (FD24) broiler cockerels. At first, guide cannula was surgically implanted in the right lateral ventricle of chickens. In experiment 1, birds were ICV injected with different doses of glutamate. In experiment 2, birds were administered with effective dose of glutamate after bicuculline. In experiment 3, chickens received muscimol prior to the injection of glutamate, and cumulative food intake was determined at 3-h postinjection. The results of this study showed that glutamate decreases food consumption in FD24 broiler cockerels (P <or= 0.05), and this reduction occurs in a dose-dependent manner. Moreover, the inhibitory effect of glutamate on food intake was significantly increased with bicuculline pretreatment, and this effect was attenuated with muscimol (P <or= 0.05). These results suggest that there is an interaction between glutamatergic and GABAergic systems (through GABA(A) receptor) on food intake in broiler cockerels.