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

Semmler J. G., Türker K. S.

Neuroscience Letters, vol.178, no.2, pp.206-210, 1994 (Scopus) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 178 Issue: 2
  • Publication Date: 1994
  • Doi Number: 10.1016/0304-3940(94)90760-9
  • Journal Name: Neuroscience Letters
  • Journal Indexes: Scopus
  • Page Numbers: pp.206-210
  • Keywords: H-REFLEX, TIBIALIS ANTERIOR, HUMAN MOTOR UNIT, SIZE PRINCIPLE
  • Istanbul Gelisim University Affiliated: No

Abstract

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 ∼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. © 1994.