RUI: Investigating the Effect of Hair Bundle Hydrodynamics in the Inner Ear

Suffolk University, Boston MA

Investigators

Abstract

Shatz 0099753 An important goal of this research is to understand the relationship between the morphology of inner ear hair bundle structures and their functionality; in particular, how the size and shape affects their response to stimuli of different frequencies. Another goal is to understand the role that an overlying membrane has in hair cell sensitivity. Hair bundles of hearing organs are usually topped by an overlying membrane called the tectorial membrane. Comparing the hydrodynamics of a model which represents an overlying membrane to one that does not should elucidate the role of an overlying membrane in hair cell sensitivity. The principal investigator previously investigated the hydrodynamics of a single hair bundle as a two-dimensional flap and as a three-dimensional hemispheroid. The 3-D analysis indicated that the 2-D model does not adequately represent hair bundle dynamics at low frequencies. This new research project is designed to extend the hemispheroid model in two directions: to include mid-frequencies, and to analyze a model with an overlying membrane in the low and high frequency regions. Students are to participate in this research in several ways: by comparing the results of different methods of solving for the distribution of the fundamental solutions; by animating the motion of the hair bundles and surrounding fluid; by studying the singularity method; studying the features of neural tuning curves. The research will enhance the students' understanding in the areas of fluid flows, numerical analysis, ear physiology, and computer programming. Results from the research are expected to contribute to the knowledge base of auditory science and also to numerical modeling of fluids. In the field of micro-mechanics the new knowledge may prove useful in developing micro-mechanical transducers of sound and motion.