My laboratory studies how hair cells in the amphibian vestibular organs that detect and encode head and body movement regenerate following damage to existing hair cells. Using a well-defined culture system in which cell proliferation is controlled with mitotic blocking agents, we are using time-lapse microscopy to provide a dynamic picture of cell proliferation and hair cell regeneration in the vestibular organs. These studies, by documenting morphological and immunocytochemical changes that occur in damaged hair cells and their neighboring supporting cells, are determining the mechanism(s) that underlie hair cell regeneration, identifying what cell types are involved, and determining how long each process takes to produce mature hair cells. Using a combination of dye-labeling, immunocytochemical, and cell ablation techniques, we are also determining how much damage is required to initiate hair cell regeneration, and shedding light on the intercellular and intracellular mechanisms that initiate and regulate this repair process. Finally, we are using biophysical and molecular biological techniques to study the physiological maturation of developing and regenerating hair cells. These studies are revealing when hair cells acquire specific transduction mechanisms and how hair cells regulate these transduction mechanisms to achieve specific physiological responses.