Anterograde tracing of projections from the dorsal raphe nucleus to the vestibular nuclei

Neuroscience. 2006 Dec 1;143(2):641-54. doi: 10.1016/j.neuroscience.2006.08.013. Epub 2006 Sep 20.

Abstract

This study used the anterograde transport of biotinylated dextran amine (BDA) to identify the course and terminal distribution of projections from the dorsal raphe nucleus (DRN) to the vestibular nuclei in rats. After iontophoretic injection of BDA into the medial and lateral regions of DRN, anterogradely labeled fibers descend within the medial longitudinal fasciculus and the ventricular fiber plexus to terminate within two discrete regions of the vestibular nuclear complex. One terminal field was located primarily ipsilateral to the injection site and involved rostrodorsal aspects of the vestibular nuclei, including superior vestibular nucleus and rostral portions of the medial vestibular nucleus (MVN) and lateral vestibular nucleus (LVN). The other terminal field involved caudoventral aspects of both ipsilateral and contralateral MVN and LVN and was less heavily innervated. These findings confirm that the vestibular nuclei are targeted by a regionally-selective projection from the DRN. The segregation of DRN terminals into anatomically distinct fields indicates that the DRN-vestibular nucleus projections are organized to selectively modulate processing within specific functional domains of the vestibular nuclear complex. In particular, these terminal fields may be organized to modulate vestibular regions involved in eye movement-related velocity storage, coordination of vestibular and affective responses, and the bilateral coordination of horizontal eye movement reflexes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Biotin / analogs & derivatives
  • Biotin / metabolism
  • Brain Mapping
  • Dextrans / metabolism
  • Male
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology*
  • Raphe Nuclei / physiology*
  • Rats
  • Rats, Long-Evans
  • Vestibular Nuclei / anatomy & histology*
  • Vestibular Nuclei / metabolism

Substances

  • Dextrans
  • biotinylated dextran amine
  • Biotin