Fig. 20

Integrated discharge activities in two sympathetic filaments to the skin (M SK N A) and kidney (M R N A) recorded in anesthetized artificially ventilated cats under neuromuscular blockade. Baroreceptor control loop is surgically interrupted. More than half of the body was immersed into a temperature-controlled water bath (BATH TEMP). a Decreasing bath temperature stepwise enhanced cutaneous and reduced renal sympathetic activity, and stepwise re-increase of temperature reduced cutaneous and increased renal sympathetic activity. The two sympathetic filaments respond oppositely as it may be expected for a thermoregulatory vasomotor response. During six intervals in the course of the experiment (bars above bath temperature curve numbered 1–6) relationships between bath temperature and mean sympathetic activities were determined. b Shows some hysteresis between downward and upward stepwise changes of bath temperature and mean cutaneous sympathetic activity (M SKIN N ACTIV). c Shows that no hysteresis develops for mean renal sympathetic activity (M RENAL N ACTIV). From Ninomiya and Fujita [58]