Thermoregulatory control of sympathetic fibres supplying the rat's tail

Abstract

We investigated the thermoregulatory responses of sympathetic fibres supplying the tail in urethane-anaesthetised rats. When skin and rectal temperatures were kept above 39 °C, tail sympathetic fibre activity was low or absent. When the trunk skin was cooled episodically by 2-7 °C by a water jacket, tail sympathetic activity increased in a graded fashion below a threshold skin temperature of 37.8 ± 0.6 °C, whether or not core (rectal) temperature changed. Repeated cooling episodes lowered body core temperature by 1.3-3.1 °C, and this independently activated tail sympathetic fibre activity, in a graded fashion, below a threshold rectal temperature of 38.4 ± 0.2 °C. Tail blood flow showed corr..