Ventral Tegmental Area Microinjected-SKF38393 Increases Regular Chow Intake in 18 Hours Food-Deprived Rats

INTRODUCTION: Ventral Tegmental Area (VTA) dopamine neurons play an important role in reward mechanisms of food intake, and VTA dopamine receptors exist on the terminal of glutamatergic and GABAergic neurons and regulate Gamma-Aminobutyric Acid (GABA) and glutamate release. To our knowledge, no evidence indicates any role for VTA D1 dopamine receptors in regular chow intake. METHODS: In this paper, different dose of SKF38393, a D1 receptor agonist, was microinjected in VTA of 18-h food deprived-conscious rats and food intake was measured. RESULTS: Our results revealed that VTAmicroinjected SKF383993 increased regular chow intake in a dose-dependent manner. The SKF3833 stimulatory effect persisted over 2 h post-injection. The results showed that the SKF38393, at doses less than 5 μg, did not affect locomotor activities. CONCLUSION: VTA D1-like and/or serotonergic receptors may be involved in regulatory pathways. the current study suggests that VTA D1-like and/or serotonergic receptors not only affects food reward but is also involved in regulatory mechanisms of regular feeding.