Increased food intake and body weight gain after lateral hypothalamic dopaminergic cell implantation

To examine our hypothesis that dopamine activity in the lateral hypothalamic area (LHA) may play a role in enhancing the process of eating, a fetal cell suspension of predominantly dopaminergic cells was bilaterally transplanted into the LHA of study rats via direct injection; controls had carrier medium injection. Thereafter, mean daily food intake was 1 g per day greater in dopaminergic cell transplanted rats vs. controls for each day of the 10-week observation period. This resulted in a significantly greater cumulative body weight gain in study rats vs. controls (386 +/- 5.1 g vs. 354 +/- 3.8 g, respectively). On sacrifice at the end of the study, transplanted cells in the LHA were viable. Our data suggest that bilateral LHA dopaminergic cell transplant which presumably resulted in chronically and persistently enhanced dopaminergic activity in the LHA is associated with overeating and consequently, an excess weight gain.