title: Tonic gravity changes alter gene expression in the efferent vestibular nucleus.
abstract: To assess effects of tonic gravity changes on efferent vestibular neurons, immediate early gene (IEG) protein expression was compared in the efferent vestibular nucleus (EVe) of adult rats exposed to microgravity during the NASA Neurolab Mission (STS-90), and matching control animals on the ground. Rats sacrificed 1 day and 12 days after launch (experiencing approximately 0g) showed significantly fewer IEG protein-expressing cells than corresponding ground control animals (at 1 g). Normal IEG protein-expressing cell numbers reappeared within I day after flight animals returned to earth, and were maintained at 14 days after landing. EVe neurons appear to play a role in gravity-induced modifications of vestibular hair cell synapses; a contribution to gravity-induced plasticity of the vestibulo-ocular reflex (VOR) is also suggested.
authors.affiliation: Dipartimento di Fisiologia e Biochimica, Università di Pisa, Italy.
authors.forename: Evan
authors.initials: E
authors.lastname: Balaban
authors.forename: Claudia
authors.initials: C
authors.lastname: Centini
authors.forename: Ottavio
authors.initials: O
authors.lastname: Pompeiano
mesh_terms: D000818:Animals; D002452:Cell Count; D015870:Gene Expression; D017781:Genes, Immediate-Early / Q000502:physiology; D006112:Gravitation; D008297:Male; D009473:Neuronal Plasticity; D009476:Neurons, Efferent / Q000166:cytology / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D012016:Reference Values; D013997:Time Factors; D014726:Vestibular Nuclei / Q000166:cytology / Q000502:physiology*
chemical_list: D016760:Proto-Oncogene Proteins c-fos