title: An ultrastructural study of the projections from the midbrain periaqueductal gray to spinally projecting, serotonin-immunoreactive neurons of the medullary nucleus raphe magnus in the rat.
abstract: In this triple-label, electron microscopic study in the rat, a lesion of the midbrain periaqueductal gray (PAG) was made so that the distribution and targets of degenerating PAG terminals could be identified in the medullary nucleus raphe magnus (NRM). Spinally projecting NRM neurons were identified by the retrograde transport of wheat germ agglutinin-horseradish peroxidase from the cervical cord. We also used immunocytochemistry to define the subpopulation of NRM neurons which were serotonin-immunoreactive. We report that both serotonergic and non-serotonergic neurons of the medulla, which project to the spinal cord, receive monosynaptic inputs from the PAG.
authors.affiliation: Department of Anatomy, University of California at San Francisco 94143.
authors.forename: S
authors.initials: S
authors.lastname: Lakos
authors.forename: A I
authors.initials: AI
authors.lastname: Basbaum
mesh_terms: D000818:Animals; D007124:Immunoenzyme Techniques; D008526:Medulla Oblongata / Q000502:physiology* / Q000648:ultrastructure; D008636:Mesencephalon / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009410:Nerve Degeneration; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D010487:Periaqueductal Gray / Q000502:physiology* / Q000648:ultrastructure; D011903:Raphe Nuclei / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D012701:Serotonin / Q000032:analysis* / Q000276:immunology; D013116:Spinal Cord / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D012701:Serotonin