Ventrolateral striatal dopamine depletions impair feeding and food handling in rats

The present study was conducted to characterize the changes in feeding behavior produced by localized depletion of dopamine (DA) in the nucleus accumbens and subregions of the neostriatum in the rat. Food-deprived rats were given at least 2 weeks of training, which consisted of being placed in a Plexiglas box and being given 15-18 g of food for a 30-min session. After the training period, rats received bilateral injections of the neurotoxic agent 6-hydroxydopamine (6-OHDA) into the nucleus accumbens, ventromedial striatum, or ventrolateral striatum. Observations were made in 30-min tests on days 3 and 7 after surgery, and measures were obtained for total food intake, time spent feeding, rate of feeding, and forepaw usage during feeding. The ventrolateral striatum was the only site at which dopamine depletion altered aspects of food intake. Rats with ventrolateral striatal DA depletion had reductions in food intake, decreases in the rate of feeding, and impaired forepaw usage during feeding. Time spent feeding was not significantly affected by DA depletion. Water consumption was significantly reduced by DA depletions in the ventrolateral striatum but not by depletions at other sites. These results indicate that ventrolateral striatal DA depletions decrease food intake by impairment of motor functions necessary for the performance of feeding behavior.