Abstract
By observing the rhythm of the impuls discharges with the E.M.G. during strychnine spasm in spinal frog, the effect of afferent stimuli was studied and the following results were obtained.
1) A series of afferent stimuli is evoked through the cutaneous nerve by placing acetic acid paper on the skin. In the short lasting stimulus the regular spasmic rhythm becomes irregular and some impulses appear in between spasmic impulses. The spasmic impulses are diminished and inhibited completely by the long lasting stimulus.
2) When continuous regular afferent stimuli are fed into spinal cord by electric stimuli applied to the cutaneous branch the inhibition of the spasm is strongly manifested. Even by a single stimulus the spasmc impulses are inhibited temporarily and the rhythm is reset by the stimulus without changing the regular period.
3) The spasmic rhythm is not disturbed by stimulating the muscle nerve.
4) When the afferent stimuli from the skin are reduced, the spasm is not ceased but the characteristic regularity of the spasm disappears.
5) The afferent route from skin is thought to be closely connected with the inhibitory interneurons which inhibit the motoneurons and play an important roll to make the spasmic rhythm.
