ASA 124th Meeting New Orleans 1992 October

3pBV6. Classification of fibers innervating the cat hindpaw.

Christin M. Checkosky

Stanley J. Bolanowski

Inst. for Sensory Res., Syracuse Univ., Syracuse, NY 13244

Neural responses were recorded from fibers innervating the glabrous skin of the cat hindpaw to determine if the preparation can be an adequate physiological model for human glabrous skin. Adaptational properties, receptive field (RF) organization, and intensity (IC) and frequency (FC) characteristics of fibers (n>116) in the medial plantar nerve were obtained in response to sinusoidal vibrations. The fibers could be grouped into four categories similar to those found for fibers innervating human glabrous skin: (a) Pacinian corpuscle fibers (22.2%) having large RFs, fast adaptation, U-shaped FCs in the 40--400 Hz range, and ICs showing plateaus at multiples of the stimulus frequency; (b) rapidly adapting fibers (22.2%) having small receptive fields, fast adaptation, U-shaped FCs in the 10--150 Hz range, and ICs showing plateaus; (c) slowly adapting type I fibers (20.0%) having small RFs, slow adaptation, positive sloping FCs in the 10--150 Hz range, and ICs showing plateaus; and (d) slowly adapting type II fibers (35.6%) having large RFs, slow adaptation, negative sloping FCs in the 20--300 Hz range, ICs without plateus, and low-rate spontaneous activity. [Work supported by NIH Grant Nos. DC00380 and DC00098.]