The role of the nucleus prepositus hypoglossi in the eye movement control

The nucleus prepositus hypoglossi (NPH) consists of a small cluster of neurons localized in the dorsomedial medulla rotrally to the hypoglossal nucleus. Due to its location and the results of electrical stimulation, the NPH was first believed to be involved in the control of tongue motility. However, the anatomical connections with several neural centers dealing with eye motility and the close correlation between eye movements and NPH neurons discharge point to a major role of this nucleus in the generation of eye movements. On the basis of anatomical and electrophysiological data, it is generally accepted that a common neural integrator for horizontal eye movements is located in the NPH.