The effects of hypothalamic and mesencephalic lesions on food and water intakes, adiposity and some endocrine criteria, in the red-winged blackbird (Agelaius phoeniceus)

Bilateral electrolytic lesions were placed either in the basomedial hypothalamus (BMH) or in the mesencephalic interpeduncular nucleus of male red-winged blackbirds. The BMH lesions induced hyperphagia, obesity and functional castration. The mesencephalic lesions induced primary hyperdipsia and hypersensitivity to angiotensin II. Some of the mesencephalic lesioned birds were hyperphagic and obese. These birds had involuted testes but still had normal levels of serum testosterone. A discussion of these results pertaining to the literature concerning avian and mammalian species is presented.