Spontaneous hair-cell renewal following gentamicin exposure in postnatal rat utricular explants

Diana Berggren, Wei Liu, Dorothy Frenz, Thomas Van De Water

Research output: Contribution to journalArticlepeer-review

23 Scopus citations

Abstract

We have established an in vitro model of long-time culture of 4-day-old rat utricular maculae to study aminoglycoside-induced vestibular hair-cell renewal in the mammalian inner ear. The explanted maculae were cultured for up to 28 days on the surface of a membrane insert system. In an initial series of experiments utricles were exposed to 1 mM of gentamicin for 48 h and then allowed to recover in unsupplemented medium or in medium supplemented with the anti-mitotic drug aphidicolin. In a parallel control series, explants were not exposed to gentamicin. Utricles were harvested at specified time points from the second through the 28th day in vitro. Whole-mount utricles were stained with phalloidin-fluorescein isothiocyanate and their stereociliary bundles visualized and counted. In a second experimental series 2′-bromo-5′deoxyuridine labeling was used to confirm the antimitotic efficacy of aphidicolin. Loss of hair-cell stereociliary bundles was nearly complete 3 days after exposure to gentamicin, with the density of stereociliary bundles only 3-4% of their original density. Renewal of hair-cell bundles was abundant (i.e. 15× increase) in cultures in unsupplemented medium, with a peak of stereociliary bundle renewal reached after 21 days in vitro. A limited amount of hair-cell renewal also occurred in the presence of the anti-mitotic drug, aphidicolin. These results suggest that spontaneous renewal of hair-cell stereociliary bundles following gentamicin damage in utricular explants predominantly follows a pathway that includes mitotic events, but that a small portion of the hair-cell stereociliary bundle renewal does not require mitotic activity.

Original languageEnglish (US)
Pages (from-to)114-125
Number of pages12
JournalHearing Research
Volume180
Issue number1-2
DOIs
StatePublished - Jun 2003

Keywords

  • Aminoglycoside
  • In vitro model
  • Mitotic activity
  • Vestibular hair-cell renewal

ASJC Scopus subject areas

  • Sensory Systems

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