Evidence for reactive astrocytes in rat vestibular and cochlear nuclei following unilateral inner ear lesion.
Eur J Neurosci
; 8(9): 2006-18, 1996 Sep.
Article
em En
| MEDLINE
| ID: mdl-8921291
ABSTRACT
We investigated whether unilateral removal of the labyrinthine and cochlear receptors induces a macroglial reaction in rat vestibular and cochlear nuclei using vimentin and glial fibrillary acidic protein (GFAP) immunochemical markers. Antibody binding was visualized using the avidin-biotin method and 3,3'-diaminobenzidine as the peroxidase substrate. In addition, double-labelling experiments were performed using specific secondary fluorescent antibodies. Potentially degenerating axon terminals were also studied using a silver impregnation method. In normal adult rats, vimentin was found only in ependymal cells, tanicytes around the fourth ventricle, endothelial cells in the blood vessels and Bergmann glia in the molecular layer of the cerebellum. In lesioned rats, all deafferented vestibular and ventral cochlear nuclei showed strong vimentin immunoreactivity. Furthermore, double-labelling experiments demonstrated that these vimentin-positive cells were also GFAP-positive. The reaction became evident on the second day after the lesion, was intense for 3-8 days and then declined until day 21. No vimentin immunoreactivity could be detected at the level of the ipsilateral dorsal cochlear nucleus. Therefore, unilateral inner ear lesion induced an astroglial reaction within the deafferented vestibular and cochlear nuclei. The decrease in the resting discharge of the primary vestibular afferents and/or in the deafferented central vestibular neurons may induce the glial reaction in the vestibular complex, whereas both degeneration and silence of the cochlear nerve and central cochlear neurons are most probably responsible for the cochlear vimentin-immunoreactive staining. The role of the reactive astrocytes in the vestibular compensation process remains to be determined.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vimentina
/
Núcleos Vestibulares
/
Astrócitos
/
Núcleo Coclear
/
Proteína Glial Fibrilar Ácida
/
Orelha Interna
Limite:
Animals
Idioma:
En
Revista:
Eur J Neurosci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
França