Title

Properties of mouse cutaneous rapidly adapting afferents: relationship to skin viscoelasticity

UMMS Affiliation

Department of Physiology

Date

3-19-2004

Document Type

Article

Subjects

Action Potentials; *Adaptation, Physiological; Animals; Elasticity; Electric Stimulation; Electrophysiology; Logistic Models; Mechanoreceptors; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Models, Biological; Nonlinear Dynamics; Normal Distribution; Skin; *Skin Physiology; Stress, Mechanical; Tensile Strength; Time Factors; Viscosity

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

When skin is stretched, stimuli experienced by a cutaneous mechanoreceptor neuron are transmitted to the nerve ending through the skin. In these experiments, we tested the hypothesis that the viscoelastic response of the skin influences the dynamic response of cutaneous rapidly adapting (RA) neurons. Cutaneous RA afferent neurons were recorded in 3 species of mice (Tsk, Pallid, and C57BL6) whose skin has different viscoelastic properties. Isolated samples of skin and nerve were stimulated mechanically with a dynamic stretch stimulus, which followed a pseudo Gaussian waveform with a bandwidth of 0-60 Hz. The mechanical response of the skin was measured as were responses of single RA cutaneous mechanoreceptor neurons. For each neuron, the strength of association between spike responses and the dynamic and static components of stimuli were determined with multiple logistic regression analysis. The viscoelastic material properties of each skin sample were determined indirectly, by creating a nonlinear (Wiener-Volterra) model of the stress-strain relationship, and using the model to predict the complex compliance (i.e., the viscoelastic material properties). The dynamic sensitivity of RA mechanoreceptor neurons in mouse hairy skin was weakly related to the viscoelastic properties of the skin. Loss modulus and phase angle were lower (indicating a decreased viscous component of response) in Tsk and Pallid than in C57BL6 mice. However, RA mechanoreceptor neurons in Tsk and Pallid skin did not differ from those in C57 skin with regard to their sensitivity to the rate of change of stress or to the rate of change of incremental strain energy. They did have a decreased sensitivity to the rate of change of tensile strain. Thus the skin samples with lower dynamic mechanical response contained neurons with a somewhat lower sensitivity to dynamic stimuli.

Rights and Permissions

Citation: J Neurophysiol. 2004 Aug;92(2):1236-40. Epub 2004 Mar 17. Link to article on publisher's site

DOI of Published Version

10.1152/jn.01033.2003

Related Resources

Link to Article in PubMed

Journal Title

Journal of neurophysiology

PubMed ID

15028748