Lateral vestibulospinal tract

The lateral vestibulospinal tract is a descending motor pathway that originates from the lateral vestibular nuclei, located in the floor of the fourth ventricle at the junction of the pons and medulla oblongata. The tract descends uncrossed through the anterior portion of the lateral funiculus (or anterolateral white column) of the spinal cord. Its fibers terminate on the cell bodies of alpha and gamma motor neurons in the anterior horns of the spinal gray matter.

The vestibular nuclei, including the lateral vestibular nucleus, receive afferent input from the inner ear (vestibular apparatus) and the cerebellum, allowing integration of sensory information regarding balance and spatial orientation. The lateral vestibulospinal tract helps adjust and maintain posture and balance. It achieves this by modulating muscle tone and enhancing the activation of anti-gravity extensor muscles, enabling the maintenance of an upright posture in response to changes in head orientation.

In addition to its role in postural control, related pathways involving the vestibular nuclei contribute to the stabilization of gaze during head movements via the vestibulo-ocular reflex. This process is mediated through the medial longitudinal fasciculus (MLF), which connects the medial vestibular nuclei to the motor nuclei of extraocular muscles, allowing for precise adjustments in eye position during head motion.