Cold-adaptation: Neuropeptide Y versus thermal signals in the development of hyperphagia

(1)Chronic cold exposure elicited immediate hyperphagia in rats, while the fasting-induced hyperphagia became enhanced after 3 weeks (but not 1 week) of adaptation.(2)The NPY-induced hyperphagia increased quickly with cold-adaptation, even in tests performed outside the cold chamber.(3)Resting core temperature decreased by about 0.4-0.6 °C after 3 weeks (full adaptation).(4)Peripheral cold signals rather than NPY appear to be important in the fast development of cold-induced hyperphagia.(5)NPY may play a slowly developing, additional role in this hyperphagia and may contribute to mild hypothermia.