Compound group I excitatory input is differentially distributed to motoneurons of the human tibialis anterior

Neurosci Lett. 1994 Sep 12;178(2):206-10. doi: 10.1016/0304-3940(94)90760-9.


The distribution of the compound group I excitatory input to various-sized motoneurones in the human tibialis anterior muscle was studied, using low-intensity electrical stimulation of the common peroneal nerve. The stimulation initiated the H-reflex response in all motor units with a latency of approximately 40 ms (range 30-45 ms). In each experiment, the amplitude of the H-reflex responses in a pair of simultaneously active motor units were assessed. It was shown that, although the stimulus intensity was identical, the amplitude of the H-reflex response was bigger in the motor unit with the higher recruitment threshold of the pair compared with the size of the reflex in the unit that had a relatively lower recruitment threshold. The present results are compared and contrasted with the findings in animals and one human study that suggested that the smaller-sized motoneurones receive larger group I excitatory input.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Algorithms
  • Differential Threshold
  • Electric Stimulation
  • Electromyography
  • Electrophysiology
  • H-Reflex / physiology
  • Humans
  • Male
  • Motor Neurons / physiology*
  • Peroneal Nerve / physiology
  • Reaction Time
  • Recruitment, Neurophysiological
  • Synapses / physiology
  • Tibial Nerve / physiology*