Lateral vestibular nucleus
The lateral vestibular nucleus is the continuation upward and lateralward of the principal nucleus, and in it terminate many of the ascending branches of the vestibular nerve.
Structure
It consists of very large multipolar cells whose axons form an important part of the posterior longitudinal bundle of the same and the opposite side.The axons bifurcate as they enter the posterior longitudinal bundle,
- the ascending branches send terminals and collaterals to the motor nuclei of the abducens, trochlear and oculomotor nerves via the ascending component of the medial longitudinal fasciculus, and are concerned in coordinating the movements of the eyes with alterations in the position of the head;
- the descending branches pass down in the posterior longitudinal bundle into the anterior funiculus of the spinal cord as the vestibulospinal fasciculus and are distributed to motor nuclei of the anterior column by terminals and collaterals.
The fibers which pass into the vestibulospinal fasciculus are intimately concerned with equilibratory reflexes.
Other axons from Deiters’s nucleus are supposed to cross and ascend in the opposite medial lemniscus to the ventro-lateral nuclei of the thalamus; still other fibers pass into the cerebellum with the inferior peduncle and are distributed to the cortex of the vermis and the roof nuclei of the cerebellum; according to Cajal they merely pass through the nucleus fastigii on their way to the cortex of the vermis and the hemisphere.