Journal of Neurophysiology, Vol 65, Issue 6 1321-1328, Copyright © 1991 by APS

ARTICLES

Response of joint capsule neurons to axial stress and strain during dynamic loading in cat

M. S. Fuller, P. Grigg and A. H. Hoffman
Division of Cardiology, University of Utah Medical School, Salt Lake City 84108.

1. Experiments were conducted to test the hypothesis that the responses of joint capsule mechanoreceptors better encode tissue stress or tissue strain. The experimental model was a small ligament from the cat knee capsule, which was stretched uniaxially in vitro. Experiments were done with either force or displacement as the controlled variable, and with steps, sinusoids, or pseudorandom Gaussian noise (PGN) as the input function. 2. The strength of coupling between neural discharge and both strain and stress was quantified during step experiments using linear correlation coefficients. The correlation between the frequency of neural discharge and stress was 0.93 +/- 0.09 (SD). The correlation between frequency of neural discharge and strain was -0.91 +/- 0.06. The magnitudes of these correlation coefficients were not significantly different. 3. The strength of coupling between neural discharge and both strain and stress during sinusoidal and PGN experiments was quantified by the use of an information theoretic statistic, transinformation. Out of 282 sinusoidal runs, transinformation between neural discharge and stress was significantly greater than transinformation between strain and neural discharge 241 times. Transinformation between strain and neural discharge was significantly greater 15 times. 4. During PGN experiments, transinformation between stress and neural discharge was greater than transinformation between strain and neural discharge in all 19 experimental runs. 5. Conditional transinformation between strain and neural discharge, given stress, was calculated for all sinusoidal and pseudorandom experiments. This statistic was greater than zero in 268 out of 289 experimental runs, indicating that a component of strain independent of stress is being signaled in the neural discharge.

This article has been cited by other articles:

				I. Birznieks, V. G. Macefield, G. Westling, and R. S. Johansson Slowly Adapting Mechanoreceptors in the Borders of the Human Fingernail Encode Fingertip Forces J. Neurosci., July 22, 2009; 29(29): 9370 - 9379. [Abstract] [Full Text] [PDF]

				P. Grigg, D. R. Robichaud, and Z. Del Prete Properties of Mouse Cutaneous Rapidly Adapting Afferents: Relationship to Skin Viscoelasticity J Neurophysiol, August 1, 2004; 92(2): 1236 - 1240. [Abstract] [Full Text] [PDF]

				Z. Del Prete, S. P. Baker, and P. Grigg Stretch Responses of Cutaneous RA Afferent Neurons in Mouse Hairy Skin J Neurophysiol, March 1, 2003; 89(3): 1649 - 1659. [Abstract] [Full Text] [PDF]

				W. Ge and P. S. Khalsa Encoding of Compressive Stress During Indentation by Group III and IV Muscle Mechano-Nociceptors in Rat Gracilis Muscle J Neurophysiol, February 1, 2003; 89(2): 785 - 792. [Abstract] [Full Text] [PDF]

				W. Ge and P. S. Khalsa Encoding of Compressive Stress During Indentation by Slowly Adapting Type I Mechanoreceptors in Rat Hairy Skin J Neurophysiol, April 1, 2002; 87(4): 1686 - 1693. [Abstract] [Full Text] [PDF]

				Z. D. Prete and P. Grigg Responses of Rapidly Adapting Afferent Neurons to Dynamic Stretch of Rat Hairy Skin J Neurophysiol, August 1, 1998; 80(2): 745 - 754. [Abstract] [Full Text] [PDF]

				P. S. Khalsa, R. H. Lamotte, and P. Grigg Tensile and Compressive Responses of Nociceptors in Rat Hairy Skin J Neurophysiol, July 1, 1997; 78(1): 492 - 505. [Abstract] [Full Text] [PDF]