Somato-sympathetic response with the extremely high latency in unanesthetized decerebrate frog.

Excitation of the sciatic nerve A-afferents in the immobilized unanesthetized decerebrated frog was found to evoke two responses in the postganglionic sympathetic efferent nerves as well as in the preganglionic ones. The first response with a latency not more than 150 ms consists of an excitatory and an inhibitory component. The second response has a latency over 2 s. Only the latter was found to disappear under the viadril-induced anesthesia. Similarities of the somato-sympathetic responses in mammals and in frogs are discussed and a reasonable physiological role of the high latency response is speculated.