Morphological and morphometric characterization of direct transdifferentiation of support cells into hair cells in ototoxin-exposed postnatal utricular explants.

Morphological and morphometric characterization of direct transdifferentiation of support cells into hair cells in ototoxin-exposed postnatal utricular explants.
Hear Res. 2015 Jan 7;
Authors: Werner M, Van De Water TR, Hammarsten P, Arnoldsson G, Berggren D
Abstract
We have studied aminoglycoside-induced vestibular hair-cell renewal using long-term culture of utricular macula explants from 4-day-old rats. Explanted utricles were exposed to 1 mM of gentamicin for 48 h, during 2(nd) and 3(rd) days in vitro (DIV), and then recovering in unsupplemented medium. Utricles were harvested at specified time points from the 2(nd) through the 28(th) DIV. The cellular events that occurred within hair cell epithelia during the culture period were documented from serial sectioned specimens. Vestibular hair cells (HCs) and supporting cells (SCs) were systematically counted using light microscopy (LM) with the assistance of morphometric software. Ultrastructural observations were made from selected specimens with transmission electron microscopy (TEM). After 7 DIV, i.e. four days after gentamicin exposure, the density of HCs was 11% of the number of HCs observed in non-gentamicin-exposed control explants. At 28 DIV the HC density was 61% of the number of HCs observed in the control group explant specimens. Simultaneously with this increase in HCs there was a corresponding decline in the number of SCs within the epithelium. The proportion of HCs in r...

Source: Hearing Research - January 7, 2015 Category: Audiology Authors: Werner M, Van De Water TR, Hammarsten P, Arnoldsson G, Berggren D Tags: Hear Res Source Type: research