Potentiation of "late" responses evoked in muscles during effort.
A study has been made of the effect of voluntary contraction on the `late' responses which can be recorded in muscles after indirect stimulation. Two late responses have been described of which the first was shown to consist mainly of a potentiated H-reflex. The potentiation of this wave was greatest in the abductor pollicis brevis muscle and depended largely on `direct' descending pathways to motoneurones. In addition, a later evoked muscle response appeared during effort; the nature of this wave was uncertain. Simple formulae have been devised to express the excitability of motoneurones to inputs from muscle nerves during effort.
D000200:Action Potentials; D000328:Adult; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction; D009431:Neural Conduction; D009475:Neurons, Afferent / Q000502:physiology; D012023:Reflex, Monosynaptic; D013116:Spinal Cord / Q000502:physiology