Body weight and regulatory deficits following unilateral nigrostriatal lesions

Unilateral nigrostriatal lesions were performed in rats by punctate injection of 6-hydroxydopamine. Lesioned animals exhibited anorexia and weight loss for 7-11 days after surgery. These animals then displayed normal rate of weight gain. However, there was a chronic depression of body weight in the lesioned animals relative to sham controls, evident for over two months after 6-hydroxydopamine administration. Unilateral nigrostriatal damage also produced major deficits in the animals' water intake in tests of prandial drinking, response to water deprivation, and response to osmotic challenge. The relationship of nigrostriatal damage to the "lateral hypothalamic syndrome" and the role of dopaminergic neurons in regulation and ingestive behaviors are discussed.