Auditory
We are using novel approaches to investigate sensory transduction and electromechanics of auditiory and vestibular hair cells, including the processes through which outer hair cells contribute to frequency selectivity and sound amplification in the mammalian cochlea. In humans, outer hair cells respond to acoustic stimuli on a cycle-by-cycle basis bestowing an incredible dynamic range of hearing. This hearing range incredibly spans over seven orders of magnitude in amplitude and provides for exquisite frequency discrimination ranging from 20 Hz to 20 kHz. However, many questions remain regarding the exact role of electromotility in the sound amplification process as well as characteristics underlying the electromotile response. Towards this end, we have developed a piezoelectric model of the hair cell motility that predicts the presence of electromechanical traveling waves along the cell as a means of achieving a flat frequency response. Furthermore, through the development of MEMS technologies for analysis of the electrical properties of these cells on an individual basis, we have been able to experimentally study the dynamics of this process and relate the findings to the model and overall cellular function. Through this research, we hope to illuminate the overall role of the hair cell in mammalian hearing (as well as balance) and further our understanding of how sound information is transmitted to the brain. Current research in this area focuses on the design, fabrication and implementation of microelectromechanical systems (MEMS) devices for electrochemical studies of hair cells. Hair cells a (more...)
The mammalian cochlea has the impressive ability to convert sound into thousands of exquisitely timed frequency and amplitude coded primary afferent neural signals. In this design nature dra (more...)
The ability of hair cells to amplify sound waves in the cochlea is incorporated into an active model of the cochlea using a series of inductively coupled coils and ferrofluid. (more...)