Sensorineural correlates of failed functional recovery after natural regeneration of vestibular hair cells in adult mice.

Vestibular hair cells (HCs) are mechanoreceptors that sense head motions by modulating the firing rate of vestibular ganglion neurons (VGNs), whose central processes project to vestibular nucleus neurons (VNNs) and cerebellar neurons. We explored vestibular function after HC destruction in adult mice, in which injections of high-dose (50 ng/g) diphtheria toxin (DT) destroyed most vestibular HCs within 2 weeks. At that time, mice had lost the horizontal vestibulo-ocular reflex (aVOR), and their VNNs failed to upregulate nuclear cFos expression in response to a vestibular stimulus (centrifugation).