### ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

## 1aBV1. Biophysical properties of a tactile mechanoreceptor: The Pacinian
corpuscle.

**B. W. Pietras
**

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S. J. Bolanowski
**

**
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*Dept. of Bioeng. and Neurosci., Inst. for Sensory Res., Syracuse Univ.,
Syracuse, NY 13244
*

*
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The Pacinian corpuscle is a tactile mechanoreceptor composed of a neural
element surrounded by a multilayered, fluid-filled accessory capsule. Receptor
potentials recorded from isolated Pacinian corpuscles in response to sinusoidal
vibrations have nonlinear, asymmetric full-wave rectified transfer functions.
The frequency response is U-shaped with a best frequency near 300 Hz. The
Pacinian corpuscle's accessory capsule was studied experimentally and modeled
theoretically to determine its mechanical contribution to the observed
physiological response. Measurements of reactive force in response to
sinusoidal compression showed that the reactive force is linear, and increases
with frequency and amplitude. The compressive force can be described by a
first-order linear differential equation of the form f(x,t)=kx+cdx/dt.
Interlamellar fluid velocities and lamellar displacements were also computed
for a range of frequencies. Computational simulations of the interlamellar
fluid flow in response to sinusoidal displacement of the surface of the capsule
shows that the multilayered structure linearizes the interlamellar fluid
velocity, thereby linearizing the interlamellar compressive force. Thus both
the mechanical filtering by the accessory capsule and the electrodynamical
properties of the neurite contribute to the nonlinear, physiological response
profiles seen in the receptor potential. [Work supported by NSF, IBN-9211561.]