Response of cutaneous hair and field mechanoreceptors in cat to paired mechanical stimuli.
1. While studying hair- and field-receptor responses to paired mechanical pulses, I observed that in approximately half the receptors the recovery of excitability following generation of an impulse took the form of a damped oscillation. 2. Oscillations could be modified or eliminated by changing the conditions of stimulation: 1) there were no oscillations with an electrical conditioning stimulus; 2) oscillations occurred only when both mechanical pulses were delivered to the surface of the skin, not when the conditioning pulse was given to a hair shaft, and only when both pulses affected the same part of the receptive field; 3) oscillation was reduced by increasing the duration of the pulses; 4) oscillation was enhanced by increasing the distance between the stimulator and the nerve terminal; and 5) maxima on the recovery curve became minima and vice versa when the direction of the conditioning pulse was changed. 3. It was concluded that recovery curve oscillations were due not to the type of hair or field receptor being stimulated, but to the conditions of stimulation. The timing of the oscillations was a function of the duration of the mechanical pulse. Furthermore, interaction was additive when the interval between stimuli was an even multiple of the pulse width. This resulted in a minimal point on the recovery curve. At odd multiples of the pulse width, the converse resulted. The evidence suggests that waves, set up in the skin by the paired mechanical pulses, interact and cause the recovery curve oscillations. Such waves could be set up by a variety of stimuli that contact the skin naturally.
D000818:Animals; D002415:Cats; D005071:Evoked Potentials; D006197:Hair; D008465:Mechanoreceptors / Q000502:physiology*; D009431:Neural Conduction; D011930:Reaction Time; D012867:Skin / Q000294:innervation*