The Bird Lab is interested in how myosin molecular motors generate force on actin filaments and how defects in this fundamental cytoskeletal mechanism cause human disease. Dr. Bird studies this question using hair cells, the neural receptors for hearing and balance that are found within the inner ear. Hair cells transduce sounds and accelerations using actin-based stereocilia that protrude from their surface. The loss of stereocilia and hair cells, due to noise exposure, ototoxic drugs and aging, is a significant cause of permanent hearing impairment that is estimated to affect more than 360 million people worldwide (1).
Myosin motors are critical for hair cell sensory transduction, with mutations in no fewer than six classes of myosin genes (I, II, III, VI, VII & XV) causing hearing loss. Using a multi-disciplinary approach, the Bird Lab is investigating how myosin motors regulate molecular trafficking within stereocilia and how this ultimately controls actin dynamics and stereocilia architecture. The lab combines data from experiments with mutant animal models, cutting-edge microscopy in live cells, and purified proteins in biochemical and single molecule assays. These studies are expected to reveal the detailed mechanisms for how stereocilia mechanosensors are assembled and maintained, and they will inform the wider goal to therapeutically enhance repair processes to promote healthy, lifelong hearing.