Glutamate transporters EAAT4 and EAAT5 are expressed in vestibular hair cells and calyx endings.

Glutamate is the neurotransmitter released from hair cells. Its clearance from the synaptic cleft can shape neurotransmission and prevent excitotoxicity. This may be particularly important in the inner ear and in other sensory organs where there is a continually high rate of neurotransmitter release.

Striated organelle, a cytoskeletal structure positioned to modulate hair-cell transduction.

The striated organelle (SO), a cytoskeletal structure located in the apical region of cochlear and vestibular hair cells, consists of alternating, cross-linked, thick and thin filamentous bundles. In the vestibular periphery, the SO is well developed in both type I and type II hair cells. We studied the 3D structure of the SO with intermediate-voltage electron microscopy and electron microscope tomography.

Psychosine induces the dephosphorylation of neurofilaments by deregulation of PP1 and PP2A phosphatases.

Patients with Krabbe disease, a genetic demyelinating syndrome caused by deficiency of galactosyl-ceramidase and the resulting accumulation of galactosyl-sphingolipids, develop signs of a dying-back axonopathy compounded by a deficiency of large-caliber axons. Here, we show that axonal caliber in Twitcher mice, an animal model for Krabbe disease, is impaired in peripheral axons and is accompanied by a progressive reduction in the abundance and phosphorylation of the three neurofilament (NF) subunits. These changes correlate with an increase in the density of NFs per cross-sectional area in numerous mutant peripheral axons and abnormal increases in the activity of two serine/threonine phosphatases (PP1 and PP2A) in mutant tissue.