[en] Many epidemiologic and experimental studies have shown that occupational exposures to aromatic solvents can induce hearing deficits in both humans and laboratory rodents. Although the end-organ of balance, the vestibular labyrinth, is in the inner ear, and has morphological and functional similarities with the cochlea, no information is available on the adverse effects of solvents on this receptor. However, epidemiological data suggest that solvent exposure can generate balance disorders, which might increase the risk of falls. In this paper, we describe the methods for assessing peripheral vestibulotoxicity using cultured vestibular samples (utricles and ampullae) collected from newborn rats. After a few days in culture, these sensory tissues become spheres filled with endolymph, which we call “cysts”. Endolymphatic potassium concentration measurements and histopathological observations were performed to understand the toxic mechanisms and identify the cellular targets of a chemical exposure, an aromatic solvent in this case. The model was tested using molecules with known effects: ouabain, a blocker of Na+/K+ ATPase pumps, gentamicin, a cytotoxic antibiotic for vestibular hair cells, and finally styrene, an aromatic solvent used in industry with well-known cochleotoxic properties.
