title: Altered phenotype of the vestibular organ in GLAST-1 null mice.
abstract: Various studies point to a crucial role of the high-affinity sodium-coupled glutamate aspartate transporter GLAST-1 for modulation of excitatory transmission as shown in the retina and the CNS. While 2-4-month-old GLAST-1 null mice did not show any functional vestibular abnormality, we observed profound circling behavior in older (7 months) animals lacking GLAST-1. An unchanged total number of otoferlin-positive vestibular hair cells (VHCs), similar ribbon numbers in VHCs, and an unchanged VGLUT3 expression in type II VHCs were detected in GLAST-1 null compared to wild-type mice. A partial loss of supporting cells and an apparent decline of a voltage-gated channel potassium subunit (KCNQ4) was observed in postsynaptic calyceal afferents contacting type I VHCs, together with a reduction of neurofilament- (NF200-) and vesicular glutamate transporter 1- (VGLUT1-) positive calyces in GLAST-1 null mice. Taken together, GLAST-1 deletion appeared to preferentially affect the maintenance of a normal postsynaptic/neuronal phenotype, evident only with increasing age.
authors.affiliation: Department of Otolaryngology, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany.
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: Schraven
authors.forename: Christoph
authors.initials: C
authors.lastname: Franz
authors.forename: Lukas
authors.initials: L
authors.lastname: Rüttiger
authors.forename: Hubert
authors.initials: H
authors.lastname: Löwenheim
authors.forename: Anna
authors.initials: A
authors.lastname: Lysakowski
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Stoffel
authors.forename: Marlies
authors.initials: M
authors.lastname: Knipper
mesh_terms: D000818:Animals; D027341:Excitatory Amino Acid Transporter 1 / Q000502:physiology*; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010641:Phenotype; D011984:Sensory Receptor Cells / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D027341:Excitatory Amino Acid Transporter 1; C493393:Slc1a3 protein, mouse