In vivo neurogenesis in the dorsal vagal complex of the adult rat brainstem.
The dorsal vagal complex (DVC) encompasses the nucleus tractus solitarii (NTS), the dorsal motor nucleus of the vagus nerve (DMX) and the area postrema (AP), that altogether provide the major integrative center for the mammalian autonomic nervous system. The adult rat DVC has been reported to contain afferent-dependent concentration of the plasticity-promoting polysialylated form of neural cell adhesion molecule [J Neurosci 21 (2001) 4721; Eur J Neurosci 14 (2001) 1194]. This prompted us to assess the occurrence of neurogenesis in the DVC of adult rats. Cumulative in vivo labeling of cell proliferation with i.p. bromodeoxyuridine (BrdU) injections was combined with phenotypic markers and confocal microscopy on serial brainstem sections throughout the DVC extent. In basal condition, sparse BrdU+ nuclei were selectively detected in the DVC according to a discrete and reproducible pattern. Some of them were found to colocalize with the neuronal markers doublecortin, HuC/D, or neuronal-specific antigen (NeuN), demonstrating that neurogenesis does occur within the DVC of adult rat. In the NTS, 10% of the BrdU+ nuclei were also NeuN+. A comparable proportion of astrogliogenesis was found in the DVC. Nestin immunohistochemistry yielded a highly specific labeling pattern at the border between AP and NTS. These data may relate to the neural stem cells that have been reported in the floor of the IVth ventricle [J Neurosci 16 (1996) 7599]. In order to assess a possible modulation of neurogenesis by afferent input in vivo, unilateral vagotomy was performed prior to cumulative BrdU treatment. Such DVC deafferentation triggered a large increase of BrdU incorporation in the ipsilateral DVC, which was associated with microglial proliferation in the DMX and with increased genesis of neurons and astrocytes in the NTS. These findings establish DVC as a novel model of adult neurogenesis that is reactive to deafferentation.
Bauer
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Laboratoire de Physiologie Neurovégétative, UMR 6153 CNRS/UMR 1147 INRA/Université Paul Cézanne-Aix-Marseille-III, Faculté Saint-Jérome, Case Postale 352, Avenue Escadrille Normandie-Niemen, 13397 Marseille cedex 20, France.
Hay
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Amilhon
B
B
Jean
A
A
Moyse
E
E
D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D039481:CD11b Antigen / Q000378:metabolism; D002452:Cell Count / Q000379:methods; D049109:Cell Proliferation; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D007839:Functional Laterality / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology* / Q000378:metabolism; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D014018:Tissue Distribution; D014628:Vagotomy / Q000379:methods
D039481:CD11b Antigen; C000714848:Dcx protein, rat; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D009479:Neuropeptides; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D010751:Phosphopyruvate Hydratase; D001973:Bromodeoxyuridine