Dentatovestibular projections in the rat

The dentatovestibular connections were investigated using anterograde and r etrograde tracing methods. All parts of the cerebellar nucleus lateralis (N L) or dentate nucleus sent fibers onto the ipsilateral vestibular nuclear c omplex. In spite of their apparently widespread area of termination, dentat ovestibular fibers were distributed differentially, according to the subreg ion of the NL they arose from. Fibers from the main, magnocellular region a nd the dorsolateral hump (dlh) reached the four main vestibular nuclei, but preferentially the superior (SV) and inferior (IV) vestibular nuclei. The projections to the lateral and the medial vestibular nuclei, which were les s abundant, essentially originated from neurons located in the dlh. Fibers arising from the parvocellular subregion of Flood and Jansen terminated wit hin the SV and IV only. Some rare reciprocal vestibulodentate projections w ere observed. These observations suggest highly integrated activities of de ntatovestibular connections related to postural, but also vestibulo-oculomo tor functions.