Fig. 8.
Average courses of cutaneous (sympath. ear), visceral (N. splanchn.) and cardiac (cardiac sympath.) nerve activities shown as changes, relative to average pre-stimulation activities, after analog integration of sympathetic discharges recorded in anesthetized rabbits with midcollicular decerebration being artificially ventilated under neuromuscular blockade. Stimulations were: ventilation with 8 % O2 in 92 % N2 (arterial hypoxia, left, n = 8) or 2 % CO in air (primary tissue hypoxia, right, n = 7), each for 4 min. Also shown are core temperature (T re), average ear skin temperature (T ear), arterial pressure (Pm ar) and heart rate (HF). The differential sympathetic response, which is typically elicited by arterial hypoxia, is completely abolished after midcollicular decerebration. In line with the equidirectional sympathetic responses to respiratory and to tissue hypoxia the tendency for ear skin vasodilatation (see Fig. 6) is lost. From Iriki and Kozawa [27]