Spinal Source for the Synchronous Fluctuations of Bilateral Monosynaptic Reflexes in Cats

Abstract

Spinal source for the synchronous fluctuations of bilateral monosynaptic reflexes in cats. J Neurophysiol 94: 3199 -3210, 2005. First published July 13, 2005 doi:10.1152/jn.00501.2005. Successive stimuli of constant intensity applied to Ia afferents produce spinal monosynaptic reflexes (MSRs) of variable amplitude. We recorded simultaneous MSRs in the left and right L7 (or L6) ventral roots of anesthetized cats. We analyzed the cross-covariance (CCV) between the amplitudes of bilateral MSRs. Long-time series (5 to 8 h) of these bilateral MSRs exhibited transitory changes in their covariations (as measured by the zero-lag peak of their CCV), thus suggesting the existence of certain neural sources contributing to produce these changes. The aim of the present study was to show that spinal centers producing negative spontaneous cord dorsum potentials (nSCDPs) contribute to maintain correlations in the amplitude of bilateral MSRs. After spinal cord transection at the L1 segment, no significant changes were observed in the correlation between the amplitude of bilateral nSCDPs versus the amplitude of bilateral MSRs. However, this correlation, as well as the peak at zero lag in the CCV between bilateral MSRs and the CCV between bilateral nSCDPs, respectively, were abolished after a subsequent longitudinal bisection at the L1-S2 spinal segments. These results suggest that lumbar spinal neurons (bilaterally interconnected) contribute to maintain the synchronous fluctuations of bilateral MSRs.

Histological correlates of N40 auditory evoked potentials in adult rats after neonatal ventral hippocampal lesion: animal model of schizophrenia

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Propagation of Sinusoidal Electrical Waves along the Spinal Cord during a Fictive Motor Task

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Stochastic Resonance in the Motor System: Effects of Noise on the Monosynaptic Reflex Pathway of the Cat Spinal Cord

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