1. The Differentiation Status of Hair Cells That Regenerate Naturally in the Vestibular Inner Ear of the Adult Mouse.
- Author
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González-Garrido, Antonia, Pujol, Rémy, López-Ramírez, Omar, Finkbeiner, Connor, Eatock, Ruth Anne, and Stone, Jennifer S.
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HAIR cells , *INNER ear , *POTASSIUM channels , *ADULTS , *MICE - Abstract
Aging, disease, and trauma can lead to loss of vestibular hair cells and permanent vestibular dysfunction. Previous work showed that, following acute destruction of; 95% of vestibular hair cells in adult mice,; 20% regenerate naturally (without exogenous factors) through supporting cell transdifferentiation. There is, however, no evidence for the recovery of vestibular function. To gain insight into the lack of functional recovery, we assessed functional differentiation in regenerated hair cells for up to 15months, focusing on key stages in stimulus transduction and transmission: hair bundles, voltage-gated conductances, and synaptic contacts. Regenerated hair cells had many features of mature type II vestibular hair cells, including polarized mechanosensitive hair bundles with zone-appropriate stereocilia heights, large voltage-gated potassium currents, basolateral processes, and afferent and efferent synapses. Regeneration failed, however, to recapture the full range of properties of normal populations, and many regenerated hair cells had some properties of immature hair cells, including small transduction currents, voltage-gated sodium currents, and small or absent HCN (hyperpolarizationactivated cyclic nucleotide-gated) currents. Furthermore, although mouse vestibular epithelia normally have slightly more type I hair cells than type II hair cells, regenerated hair cells acquired neither the low-voltage-activated potassium channels nor the afferent synaptic calyces that distinguish mature type I hair cells from type II hair cells and confer distinctive physiology. Thus, natural regeneration of vestibular hair cells in adult mice is limited in total cell number, cell type diversity, and extent of cellular differentiation, suggesting that manipulations are needed to promote full regeneration with the potential for recovery of vestibular function. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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