Dr. George McConnell
Department of Biomedical Engineering
Stevens Institute of Technology
Why Random Patterns of Deep Brain Stimulation Less Effectively Treat Parkinson’s Disease: Insights from In Vivo Studies
Deep Brain Stimulation (DBS) of the subthalamic nucleus effectively treats several motor symptoms of Parkinson’s disease (PD), however, the mechanisms of action of DBS are unknown. Random temporal patterns of DBS are less effective than regular DBS, but the neural basis for this dependence on temporal pattern of stimulation is unclear. We quantified behavior and single-unit neuronal activity in parkinsonian rats to test the hypothesis that the ineffectiveness of irregular DBS is caused by a failure to mask low-frequency oscillatory activity. Irregular DBS relieved symptoms less effectively than regular DBS, even when delivered at a high average rate. The reduced effectiveness of random DBS paralleled a failure to suppress low-frequency oscillatory activity and suggest that long pauses during random DBS are responsible for the reduced effectiveness, because these pauses enable the propagation of low-frequency oscillatory activity. These results demonstrate a correlation between efficacy of DBS, temporal regularity of stimulus trains, and changes in neuronal oscillatory activity in the basal ganglia, highlighting the importance of considering temporal patterns - as opposed to simply the rate - of both stimulation and neuronal firing in studying the mechanisms of DBS for neurological disorders.
Prof. McConnell earned his B.S. and M.S. degrees in Biomedical Engineering from Drexel University and his Ph.D. degree in Bioengineering from Georgia Institute of Technology (with Ravi Bellamkonda) in 2008. He was a Research Scientist in Warren Grill’s lab in the Department of Biomedical Engineering at Duke University prior to joining the faculty at Stevens Institute of Technology in 2015. Prof. McConnell’s research interests lie in Neural Engineering. Specifically, he is interested in designing reliable brain-machine interfaces and developing neural stimulation strategies that minimize side effects and enhance therapeutic benefit. Prof. McConnell’s research is supported by the National Institutes of Health (NINDS), the Branfman Family Foundation, and the Brain & Behavior Research Foundation.