Up close and personal – it's how Katherine Rennie, Ph.D., interacts daily with vestibular system hair cells. Now in her second year of funding by the Deafness Research Foundation, Rennie's work at the University of Colorado may lead to novel treatments for balance disorders that perplex and plague so many people.
Rennie first became interested in hair cell research under the tutelage of Jonathan Ashmore, Ph.D., of the University of Bristol in Avon, England, where she completed her graduate studies. Rennie first studied auditory hair cells in England and when she jumped over “the pond" she made the jump to vestibular system hair cells as well.
On a typical day in the lab, Rennie starts by harvesting the utricle, a small gravity-sensing organ containing two types of hair cells in the vestibular system of mammals, birds and reptiles. She then prepares the utricle in a solution that mimics its natural environment, extending its usefulness for research for a few hours. In that precious time, Rennie will conduct experiments that further our understanding of vestibular hair cells – knowledge that can eventually lead to targeted pharmaceutical interventions for dizziness, vertigo and other balance disorders.
Though it is hard to imagine precision on such a microscopic scale, Rennie gets to know hair cells better by probing the bundles of hairs at the top of individual hair cells and observing and recording how they react. Researchers have learned that these bundles of tiny hairs, or stereocilia, are arranged differently and vary in number in different regions of the utricle. Rennie’s hypothesis is that these differences in stereocilia number and arrangements are related to how hair cells sense vestibular information, such as the changes your body senses as you go up and down in an elevator, and how that information is translated to the vestibular nerves and ultimately the brain.
Rennie conducts experiments several days a week and balances time in the lab with teaching and administrative responsibilities, including oversight of medical students and otolaryngology residents working on their own research projects.
Rennie’s study of one of the two types of hair cells found in the vestibular system is in collaboration with Tony Ricci, Ph.D., of the Neuroscience Center and Kresge Hearing Research Labs in New Orleans. While Hurricane Katrina clean-up efforts continue, Dr. Ricci is temporarily housed in the National Institute on Deafness and Other Communication Disorders. Fortunately, Rennie had backup data that kept Katrina's impact on the collaboration to a minimum. “We didn’t lose any important data – we just lost time," says Rennie.
Outside the lab, Rennie enjoys the great outdoors of central Colorado with her boys, Robert and Evan, ages four and seven, and her husband Tim Benke, a pediatric neurologist and researcher. Although her boys are still too young to understand Rennie's work, they love the fieldwork. In the summer, Rennie takes her family to the marine biology laboratory in Woods Hole, Mass., where the kids practice their future scientific observation skills with tanks of marine animals.
