Whole organ culture of the postnatal sensory inner ear in simulated microgravity

Among the three major biological in vitro models, cell culture, tissue culture, and organ culture, the latter provides the closest approximation to the in vivo situation, but also requires the most demanding culture conditions. Due to its small size and complex tissue architecture, the mammalian inner ear provides a particular challenge to the development of whole organ culture. Using a rotating bioreactor system with simulated microgravity conditions, the entire mouse inner ear organ can be maintained in culture for up to seven days with preservation of sensory organ morphology and robust marker protein expression in sensory hair cells. Controlled sensory cell lesions can be induced by the ototoxic agent, neomycin sulphate, as a toxicologic model of hair cell degeneration and hair cell loss. The results demonstrate that simulated microgravity organ culture of the inner ear affords an in vitro model for the investigation of developmental, regulatory, and differentiation processes, as well as toxicological, biotechnological, and pharmaceutical screening applications within the normal and pathologic sensory hearing organ.