抄録
The physiological evidence of the efferent innervation to the chemoreceptor was sought in the carotid labyrinth of the toad. A few-fiber chemosensory preparation was splitted from the glossopharyngeal nerve at its peripheral cut end, and the rest part of the nerve was stimulated electrically. The stimulation reduced remarkably the chemosensory discharge in this nerve strand. To seek the derivation of these inhibitory fibers a few-fiber preparation was peeled from the intact glossopharyngeal nerve, and the sympathetic nerve and the vagus group root were stimulated respectively. The sympathetic stimulation provoked an in-hibitory effect on chemosensory activity in ten of seventeen preparations. In three of these ten the vagus group root stimulation was also effective. In one instance the vagus group root stimulation brought about the inhibitory effect, while the sympathetic did not. In the other six, no remarkable effect was obtained by both stimulations. The mechanism provoking these effects was discussed.
