Axon collaterals to the extraocular motoneuron pools of inhibitory vestibuloocular neurons activated from the anterior, posterior and horizontal semicircular canals in the cat

Yoshio Uchino, Shuji Suzuki

Research output: Contribution to journalArticle

23 Citations (Scopus)


The branching pattern of inhibitory vestibuloocular neurons and their synaptic contacts with extraocular motoneurons were studied by means of spike-triggered averaging and local stimulation techniques. Individual vestibuloocular neurons activated by stimulation of the ampullary nerve of the anterior semicircular canal (ACN) inhibited motoneurons in both the ipsilateral (i-) trochlear nucleus and i- inferior rectus motoneuron pools. Individual vestibuloocular neurons receiving input from the ampullary nerve of the posterior semicircular canal (PNC) inhibited motoneurons in both the i-inferior oblique and i-superior rectus motoneuron pools. Probably, these axonal trajectories underlie conjugate eye movement during vertical head rotation. No conclusive evidence was found to indicate that single inhibitory vestibular neurons receiving input from the horizontal semicircular canal (HCN) give off axon collaterals to the i-abducens and the contralateral medial rectus motoneurons. A separate projection of HCN-related neurons to motoneurons supplying the lateral and medial rectus muscles might be useful for convergence during horizontal head movement.

Original languageEnglish
Pages (from-to)129-135
Number of pages7
JournalNeuroscience Letters
Issue number2
Publication statusPublished - 1983 Jun 16
Externally publishedYes



  • axonal branching
  • inhibitory
  • ocular motoneuron
  • vestibular neuron

ASJC Scopus subject areas

  • Neuroscience(all)

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