IBN-9724123 PI: Peterson The inner ear of vertebrates contains mechanosensory receptors called hair cells. Each cell has extending from its surface a tuft of hairlike microscopic processes called a ciliary bundle. This ciliary bundle is extremely sensitive to deflection, and the amount and direction of mechanical deflection leads to a nerve signal from the ear about head position or about sound. There are differences in bundle morphology in different parts of the ear, but a possible functional importance for these differences has remained largely speculative. This project is a collaborative bioengineering effort involving modern imaging and computational technology to clarify possible functions for this diversity. LIght and electron microscopy are used for detailed measurements of the bundles, which are incorporated into a computational finite-element model to quantify the contribution of different structural elements to bundle micromechanics. A new fiber-optic system is used for direct tests of the bundle stiffness in isolated living hair cells, to compare with model predictions for different morphological categories of hair cell bundles. Results will have impact not only on auditory and vestibular sensory biology, but more broadly on understanding echanoreception, and with a likely impact on artificial biosensors and biotechnology at the nanoscale.
