Mark D. Does, Ph.D.

Five biomedical engineering professors and an electrical engineering and computer science professor are celebrating news about newly approved or resubmitted Research Project Grants (R01) from the Nationals Institutes of Health.

With the grants, their teams – in collaboration with Vanderbilt University Medical Center — are performing groundbreaking research in areas as diverse as percutaneous heart surgery, advanced diffusion weighted magnetic resonance imaging and custom programming for cochlear implant recipients.

Mark Does, professor of biomedical engineering, professor of radiology and radiological sciences, professor of electrical engineering, director of graduate studies in biomedical engineering, is developing new kinds of magnetic resonance imaging tools that allow researchers to see and characterize neuronal microstructures in small animals. He proposes to map normal and abnormal rat and mouse brains and study the histology of white matter regions and develop and disseminate the resulting new, state-of-the-art MRI methods and mapping software for those. (1R01EB019980-01A1, $1.8 million over four years)

The brain is comprised of gray and white matter, made of neurons with axon projections.

In mainly white matter, myelin wraps to form a sheath around axon fibers. This accelerates nerve signals by electrically insulating the axon. Many white matter diseases involve loss of myelin, which makes diagnosing the health of myelin clinically very important.

Reporting this month in the journal NeuroImage, Mark Does, Ph.D., and colleagues demonstrate a revised model for quantitatively estimating g-ratio from MRI. Their report shows that the g-ratio obtained from MRI is the axon-area-weighted measure of g-ratio across all axons.