Norma Slepecky, a professor in the bioengineering and neuroscience department of the L.C. Smith College of Engineering and Computer Science, holds a model of the human ear's inner structures.
From the ridges and furrows of the outer ear to the snail-shell-shaped cochlea, the human ear is an elegant, complicated instrument. No wonder it is so susceptible to damage from disease, loud noises, and, ultimately, the aging process. At the Institute for Sensory Research, Norma Slepecky is seeking a better understanding of that instrument, and her research could lead to methods for preventing or even repairing hearing loss. "I'm looking at several aspects of the ear, such as how the structure of the cells relates to hearingspecifically the damaging effects of noise and antibiotic drugs," she says. "I want to know how the damage is caused, how we might prevent it, and how we can use the damage to study repair mechanisms and the generation of new cells."|
Slepecky '65, G'68, a professor in the bioengineering and neuroscience department of the L.C. Smith College of Engineering and Computer Science, receives funding from the National Institutes of Health and the National Organization for Hearing Research. She recently received a $15,000 grant from the Deafness Research Foundation to study the effects of the antibiotics gentamicin and streptomycin on the ear's cochlear and vestibular systems. Slepecky is studying which of the drugs is more toxic to the cochlea (which enables hearing) or the vestibular sense organs (which affect equilibrium). One or both drugs could be used to treat patients suffering from Meniere's disease, a debilitating disorder characterized by varying degrees of hearing loss and dizziness. "One way to stop the dizziness is to destroy the vestibular nerve through surgery," Slepecky says. "If you could give a drug that selectively destroys the vestibular system, but doesn't make you lose your hearing, then you could use the antibiotic's bad properties in a good way."
Once she's found a way to destroy the system, Slepecky can study whether it regenerates. "For neuroscience that's fascinating," she says. "You're always told your brain cells never regenerate, but the sensory systems of your ears are modified neurons, brain cells. Some in the vestibular system do come back. Also, do the nerves come back? The cells by themselves aren't effective at communicating things to your brain unless the neurons make the right connections.
"I'm not claiming that my research will be the definitive research in this area, but certainly the whole focus of inner ear research today is repair and regeneration of the sensory component. We know that it happens in the auditory systems of fish and birds, and in the vestibular system of humans. So it's a question of finding the right stimulus or support system for these cells to make them grow backin a way that they can function and interact with nerves."
Slepecky's other research projects involve hearing loss from noise. Every year she lectures her students about the dangers of overexposure to noise. "Loud noise causes you to lose your hearingit's a given," she says. "Noise is usually defined as something loud that you don't like, but we're exposed to lots of noises that are either unavoidable or that we like, but could be damaging."
Slepecky has found, however, that all noises are not created equal. Very low levels of noise apparently condition the ear and protect it from some louder noisesa phenomenon with tremendous implications for workplace applications where ear protectors are now commonly used. The protection must result from biochemical, metabolic, or structural changes in the ear, Slepecky explains. To find out which, she and her students examine tissue samples microscopically or biochemically, looking for changes in cell number, shape, and relationship to other cells. "If you could find which molecular changes allow for protection, then you might be able to induce them on command, rather than having somebody listen to noise for three hours," she says.
Many students take an active role in Slepecky's work. Brian Bane '98, who graduated with a degree in biochemistry, worked for almost two years on a project to distinguish some of the biochemistry of cellular structures in the cochlea. "It made me move above and beyond what a normal undergraduate education requires," he says. "I learned skills that are going to see me through for the rest of my life, and I came out with a pretty good research project."