Genetic selection for growth rate alters hypothalamic satiety mechanisms in chickens

The relationship between genetic and hypothalamic obesity was investigated by comparing the response to electrolytic lesioning of the ventromedial hypothalamus in chickens from lines developed through divergent selection for high and low body weight. The high-weight line exhibits obesity, while the low-weight line is relatively lean. Lesioned adult chickens from the low-weight line exhibited the expected obesity syndrome, while lesioned high-weight-line chickens exhibited neither increased feed consumption nor increased body weight. The results suggested that artificial selection for increased body weight resulted in a diminution of hypothalamic satiety mechanisms.