The effects of bicuculline and muscimol on glutamate-induced feeding behavior in broiler cockerels

摘要

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 ≤ 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 ≤ 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.