Altered Phenotype of the Vestibular Organ in GLAST-1 Null Mice

作者：Schraven Sebastian P; Franz Christoph; Ruettiger Lukas; Loewenheim Hubert; Lysakowski Anna; Stoffel Wilhelm; Knipper Marlies^*

来源：Journal of the Association for Research in Otolaryngology, 2012, 13(3): 323-333.

DOI：10.1007/s10162-011-0311-2

• GLAST-1
• vestibular hair cells
• supporting cells
• otoferlin
• KCNQ4
• VGLUT

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.

• 出版日期2012-6