Spinal source for the synchronous fluctuations of bilateral monosynaptic reflexes in cats.
J Neurophysiol
; 94(5): 3199-210, 2005 Nov.
Article
en En
| MEDLINE
| ID: mdl-16014789
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.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Reflejo Monosináptico
/
Raíces Nerviosas Espinales
/
Relojes Biológicos
/
Transmisión Sináptica
/
Estimulación Eléctrica
/
Vértebras Lumbares
/
Neuronas Motoras
Límite:
Animals
Idioma:
En
Revista:
J Neurophysiol
Año:
2005
Tipo del documento:
Article
Pais de publicación:
Estados Unidos