Fig. 3

Regionally differential sympathetic responses to cooling (black bar) and warming (white bar) deep-body temperature sensors in the spinal cord, using a water-perfused tube inserted into the vertebral peridural space of anesthetized, artificially ventilated rabbits under neuromuscular blockade in the condition of midcollicular decerebration (means ± standard errors, n = 8). Shown are sympathetic activity changes, relative to average activity levels during pre-stimulation periods, after analog integration of sympathetic discharges recorded from multi-fiber preparations of a sympathetic filament containing spontaneously active fibers innervating the ear skin (sympath. ear), from a filament of a splanchnic nerve branch (N. splanchn.) and from a filament separated from a sympathetic branch innervating the heart (cardiac sympath.). Further shown are courses of deep-body temperature (T _re) and peridural vertebral space temperature (Tvc), arterial pressure (Pm _ar ) and heart rate (HF). Cooling activates sympathetic innervation to the skin and causes parallel reductions of visceral and cardiac sympathetic efferent activities. Warming produces the opposite effects: reduction of cutaneous sympathetic activity reflected by rising ear skin temperature (T _ear ) and parallel activation of visceral and cardiac sympathetic efferent activities. From Iriki and Kozawa [27]