ASA 127th Meeting M.I.T. 1994 June 6-10

2aBV8. The effects of aging on temporal summation in the Pacinian (P) channel.

Christine M. Checkosky

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

George A. Gescheider

E. J. Beiles

Hamilton College, Clinton, NY 13323

Stanley J. Bolanowski

Ronald T. Verrillo

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

Threshold for detecting vibratory stimuli of variable duration were measured in 16 subjects ranging in age from 19 to 81 years. The 250-Hz vibratory stimuli were applied to the thenar eminence of the hand through a large (2.9 cm[sup 2]) contactor, selectively activating the P channel in glabrous skin. Detection thresholds were higher in older than in younger subjects. Correlation coefficients for the relation between threshold and age ranged from 0.94 to 0.96 depending on signal duration. In addition, the amount of temporal summation was negatively correlated with age. Both the elevated detection thresholds and the reduced amount of temporal summation in elderly subjects may be partially due to the decrease in the number of Pacinian corpuscles in the hand that occurs with aging. Another factor that could be responsible for the reduced temporal summation in older as compared to younger subjects is impairment of the temporal integrator. [Work supported by NIH, NIDCD.]