Amygdaloid lesion-induced obesity in rats in absence of finickiness.

Female rats with lesions of the most posterodorsal aspects of the amygdala were tested for their reaction to a variety of manipulations of their food and water supply. Compared to control animals, the rats with lesions were hyperphagic and displayed excess weight gain. However, they did not consume more of a high-fat diet or of a sucrose solution than did controls, nor did they consume less than controls when their food or water supply was adulterated with quinine or when switched from pellets to ground chow. On a fine-powder diet, control animals lost weight whereas rats with lesions gained weight. Rats with lesions consumed more saline than controls in a two-bottle preference test. These results are consistent with those of earlier studies of other species with amygdaloid damage. It is concluded that rats with lesions of the posterodorsal amygdala are hyperphagic in absence of the marked finickiness that characterizes some other brain lesion-induced obesity syndromes.