title: New neurons in the vestibular nuclei complex after unilateral vestibular neurectomy in the adult cat.
abstract: Recent findings revealed a reactive neurogenesis after lesions and in several models of disease. After unilateral vestibular neurectomy (UVN), we previously reported gamma-aminobutyric acid (GABA)ergic neurons are upregulated in the vestibular nuclei (VN) in the adult cat. Here, we ask whether this upregulation of GABAergic neurons resulted from a reactive neurogenesis. To determine the time course of cell proliferation in response to UVN, 5-bromo-2'-deoxyuridine (BrdU) was injected 3 h, 1, 3, 7, 15 and 30 days after UVN. We investigated the survival and differentiation in UVN cats injected with BrdU at 3 days and perfused 30 days after UVN. Results show a high number of BrdU-immunoreactive nuclei in the deafferented VN with a peak at 3 days after UVN and a decrease at 30 days. Most of the newly generated cells survived up to 1 month after UVN and gave rise to a variety of cell types. Confocal analysis revealed three cell lineages: microglial cells (OX 42/BrdU-immunoreactive cells); astrocytes [glial fibrillary acidic protein (GFAP)/BrdU-immunoreactive cells]; and neurons (NeuN/BrdU-immunoreactive cells). That UVN induced new neurons was confirmed by an additional marker (nestin) expressed by neural precursor cells. We show that most of the newly generated neurons have a GABAergic phenotype [glutamate decarboxylase (GAD)-67/BrdU-immunoreactive cells]. Morphological analysis showed two subtypes of GABAergic neurons: medium and small (30 vs. 10 microm, respectively). This is the first report of reactive neurogenesis in the deafferented VN in the adult mammalian CNS.
authors.affiliation: UMR 6149 Neurobiologie Intégrative et Adaptative Pôle 3C, Comportement, Cerveau, Cognition, Centre de St Charles, Case B, 3 Place Victor Hugo, 13331 Marseille Cedex 3, France. tighilet@up.univ-mrs.fr
authors.forename: Brahim
authors.initials: B
authors.lastname: Tighilet
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Brezun
authors.forename: Gustave Dit Duflo
authors.initials: GD
authors.lastname: Sylvie
authors.forename: Céline
authors.initials: C
authors.lastname: Gaubert
authors.forename: Michel
authors.initials: M
authors.lastname: Lacour
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001973:Bromodeoxyuridine / Q000378:metabolism; D039481:CD11b Antigen / Q000378:metabolism; D002415:Cats; D049109:Cell Proliferation; D048429:Cell Size; D007839:Functional Laterality; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000145:classification / Q000502:physiology*; D020127:Recovery of Function; D013997:Time Factors; D014725:Vestibular Nerve / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery; D014726:Vestibular Nuclei / Q000473:pathology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D039481:CD11b Antigen; D007527:Isoenzymes; D009419:Nerve Tissue Proteins; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; D001973:Bromodeoxyuridine