Affiliations: [a] Department of Biology, Åbo Akademi University, Biocity, Turku, Finland | [b] Neuroscience Center, Institute of Biomedicine/Anatomy, University of Helsinki, Finland | [c] Department of Otorhinolaryngology, University of Helsinki, HUCH, Helsinki, Finland
Correspondence:
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Corresponding author: Dr. Antti A. Aarnisalo, Department of Otorhinolaryngology, Univ. Helsinki, HUCH, Haartmanink. 4 e, 00290 Helsinki, Finland. Tel.: +358 9 4711; Fax: +358 9 47175010; E-mail: antti.aarnisalo@hus.fi
Abstract: In the auditory periphery, GDNF has been shown to have a trophic effect to spiral ganglion neurons, both during development and in adult animals. We have studied the effect of unilateral labyrinthectomy (UL) on protein levels and expression of GDNF multicomponent receptor complex: the ret tyrosine kinase and coreceptor GFRα-1 in the medial vestibular nucleus of the adult rat. GFRα-1 protein levels display an increasing trend in ipsilateral medial vestibular nucleus culminating at 48 h post UL. On the other hand, GFRα-1 mRNA expression levels in ipsi- and contralateral medial vestibular nucleus show a steadily decreasing trend that is significant at 1 week post-lesion. Protein levels for c-Ret isoforms also show an initial bilateral decreasing trend that ceases at 48 h in ipsilateral medial vestibular nucleus but persists on the contralateral side. c-Ret mRNA expression levels show a significant decrease at 4 h post UL followed by another significant decrease 1 week post UL. Our data would suggest that neurotrophins belonging to the GDNF family are involved in this model of post-lesional CNS plasticity.
Keywords: GDNF, rat, c-ret, GFRα-1, vestibular compensation
