MUSCLE SPINDLE RESPONSES TO VIBRATORY STIMULI AT CERTAIN FREQUENCIES

1. Vibratory stimuli from 25-500c/s were applied to the cat's triceps surae muscle. The group Ia discharge from the muscle spindle was obtained from the dorsal root filament.2. The new term “response ratio”, which shows the number of spikes res ponding to one cycle of vibration, was used and this ratio observed at every vibratory frequency.3. There were sometimes a few gaps or valleys in the response's ratiofrequency curve, the frequency of which showed simple integral relations, such as one to two or two to three.4. The discharge patterns at every frequency changed in a staircase manner.5. It was discussed that these phenomena may be due to the physical properties of each muscle spindle.