[Effects of partial unfused contractions of the gastrocnemius medialis muscle on homonymous and synergist motor neurons in cats].
Autogenetic inhibition of homonymous and synergist motoneurones can be elicited by very weak partial twitches of gastrocnemius medialis muscle, but during sustained contractions the amplitude of inhibitory post-synaptic potentials decreases quickly. A similar decrease also occurs during stronger contractions. The mechanism responsible for this decrease is still active in low spinal preparations. Pre-synaptic inhibition of Ib afferent fibres might contribute to this reduction of efficiency in the transmission of Ib afferent inputs to motoneurones.
Horcholle-Bossavit
G
G
Laboratoire de Neurophysiologie, Collège de France, Paris.
Jami
L
L
Lafleur
J
J
Lamy
F
F
Zytnicki
D
D
D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D007866:Leg; D008564:Membrane Potentials; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction; D013116:Spinal Cord / Q000502:physiology; D009435:Synaptic Transmission
Effets de contractions partielles non-fusionnées du muscle gastrocnémien médian sur les motoneurones homonymes et synergistes chez le chat.