A Promotive Effect of Low-Level Laser on Hair Cell Regeneration Following Gentamicin Induced Ototoxicity in Postnatal Organotypic Culture of Rat Utricles / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: In normal postnatal mammalian inner ear sensory epithelium, regeneration of hair cells is a very rare event, but there is hair cell regeneration with partial restoration of the vestibular sensory epithelium following ototoxic damage. In this study, the effects of low-level laser on hair cell regeneration following gentamicin exposure in postnatal organotypic culture of rat utricles were investigated. MATERIALS AND METHOD: A long term organotypic culture of 2 to 7 day old rat utricular maculae was established to study aminoglycoside-induced vestibular hair cell renewal. The utricles were exposed to 1 mM of gentamicin for 48 hr and allowed to recover in a culture medium only or in a medium with daily irradiation of low-level laser, whereas the control group was not exposed to gentamicin. Whole-mount utricles were stained with FM1-43, which are known to be an efficient marker, to identify live hair cells in cultured tissues. RESULTS: Loss of hair cells was nearly stopped from 2 days after exposure to gentamicin ; a peak of regeneration was reached after 18 days and sustained for two weeks in the medium with the irradiation of low-level laser. CONCLUSION: These results suggest that low-level laser promotes spontaneous hair cell regeneration following gentamicin damage in utricular explants.