Frequency responses of down- and guard-hair receptors in the cat

In the saphenous nerve of the barbiturate-anesthetized cat, single-unit recordings were made while stimulating guard-hair of down-hair receptors with sinusoidal or narrow-band "noise" displacements. From the units' frequency responses it was inferred that a significant contribution to their firing rate is made by stimulus displacement as well as by stimulus velocity. The appellation "velocity detector" for these units is only partially correct. The proposed division of guard-hair units into types G1 and G2 was not supported by the results obtained with the stimulus used in this investigation.