Feeding pattern in obese Zucker rats after dopaminergic and serotonergic LHA grafts

To study the role of the lateral hypothalamic area (LHA) dopamine and serot onin in the regulation of feeding pattern during obesity, embryonic dopamin ergic and serotonergic neurons from mesencephalon and rombencephalon of lea n rats were grafted into the LHA of adult obese Zucker rats. Compared to th e pregrafting period, a smaller increase in meal size occurred in both sero tonin-grafted (9%) and dopamine-grafted (31%) rats us control rats (51%). T here was also a smaller decrease in meal number in both serotonin-grafted ( 3%) and dopamine-grafted (13%) rats us control rats (28%). Although the cha nges in feeding pattern resulted in a decrease in total food intake in sero tonin-grafted rats (5%) ss control rats, no differences in body weight gain were observed in grafted ys control rats for the duration of the study. Si nce adult obese Zucker rats are known to have an increased meal size and de creased meal number relative to lean rats, the data indicate the involvemen t of LHA dopamine and serotonin in the regulation of feeding pattern during obesity. NeuroReport 10:1049-1053 (C) 1999 Lippincott Williams & Wilkins.