Major aim of this project is to determine the neural mechanisms involved in food intake and its conditioning effects. We microinjected the dopamine D2 receptor agonist quinpirole, which temporarily inactivates dopaminergic neurons, into the posterior ventral tegmental area (pVTA), and we examined its effects on food intake and place conditioning. We found dose-dependent effects of quinpirole. The doses of quinpirole that did not reduce food intake or induce conditioned place avoidance by itself, prevented induction of food-induced conditioned place preference. Higher doses of quinpirole induced conditioned place avoidance and reduced food intake. These results suggest that dopaminergic neurons originating from the posterior VTA play an important role in conditioned place preference induced by food reward; however, it is not clear exact role of these dopamine neurons in regulation of food intake. We are currently investigating the effects of quinpirole injections into the anterior VTA and substantia nigra, which also contain dopaminergic neurons.
|Liu, Zhong-Hua; Shin, Rick; Ikemoto, Satoshi (2008) Dual role of medial A10 dopamine neurons in affective encoding. Neuropsychopharmacology 33:3010-20|