RESUMO
BACKGROUND AND OBJECTIVES: Organotypic culture of organ of Corti maintains the basic organization of the spiral lamina and can conserve several factors responsible for the neuronal growth of the nervous components. The explant culture technique has been widely used in organ culture system, however, the floating drop method using collagen gel was also developed as a simple and reliable method. In order to study the effect of growth factors on the regenerative and protective ability of cochlear hair cells, we first had to establish an in vitro model of the inner ear. MATERIALS AND METHODS: Organ of Corti was obtained from newborn rats and cultured with the floating drop method using collagen gel. Immunohistochemical staining was used to visualize the stereocilia and scanning electron microscopic study was also carried out. RESULTS: Explants were maintained up to 10 days without contamination. Morphologically, immunofluorescent staining with phalloidin showed well preserved outer and inner hair cells with stereocilia on the second day of culture. On the tenth day of culture, the staining result showed inner and outer hair cells, although the stereocilia were poorly stained. In scanning electron microscopic examination, an explant on the tenth day of culture showed preserved outer and inner hair cells and stereocilia, although damaged hair cells and stereocilia were also observed. CONCLUSION: The floating drop method was an appropriate method for maintaining the organ of Corti in vitro with the advantage being the easiness in its manual manipulation.