Axonal Branching in Different Extraocular Motoneuron Pools of Single Vestibular Neurons Activated by the Stimulation of the Posterior Semicircular Nerve in the Cat

Abstract

Axonal branches of single vestibular neurons activated by stimulation of the ampullary nerve of the posterior semicircular canal in the cat were studied by mean of local antidromic stimulation in the trochlear and the oculomotor nucleus. These vestibuloocular neurons were located in the rostral half of the descending vestibular nucleus and the lateral part of the medial vestibular nucleus. The majority of vestibuloocular neurons projecting to the inferior rectus motoneuron pool in the contralateral oculomotor nucleus was activated antidromically from the contralateral trochlear nucleus as well. This suggests that axonal branches of a single vestibular neuron project to both nuclei.