The Neuromodulation Research Center
Parkinson's Research Using Non-Human Primates
by Tanner Hubbard
Background
Over the course of the 2021-2022 school year at Macalester, I volunteered at the Neuromodulation Research Center (NMRC) through the Department of Neurology at the University of Minnesota. The focus of much of the NMRC’s work is on Parkinson’s Disease (PD), studying its pathophysiology, investigating the mechanisms of deep brain stimulation (DBS) on PD, and working to improve the effectiveness of this treatment option. While DBS has revolutionized the treatment of Parkinson’s Disease, it often remains as a last-resort for those who no longer respond to medication or other treatment options. DBS involves the insertion of electrodes deep into the brain, an invasive, risky, and lengthy procedure that is not widely accessible, especially to minority populations (Chan et al., 2014).
Parkinson’s Disease is a relatively prevalent disorder, with some 10 million people living with PD globally and around 60,000 newly diagnosed cases per year in the United States alone. Moreover, the estimated direct and indirect healthcare cost of PD is estimated to be around $52 billion in the US alone, with medication costing $2500 per year and surgery (DBS) costing $100,000 per person (Parkinson’s Foundation, n.d.). Combined, the prevalence, cost, and debilitating nature of Parkinson’s Disease make it both a major personal and public health concern.
Top: A graphic showing the technical aspects of deep brain stimulation.
Bottom: An infographic showing some of the most common symptoms associated with Parkinson's Disease.
The NMRC
Principally a translational research facility, the NMRC works to bring basic scientific discoveries directly into the lives of patients suffering from neurological disorders in order to ameliorate symptoms, reduce side effects, and enhance function and quality of life. With these overarching goals in mind, the NMRC uses a non-human primate (NHP) model for PD and has many ongoing research projects, most of which are under the direction of Dr. Jerrold Vitek, the NMRC’s director and professor and chair of Neurology at the University of Minnesota. Both a physician and a scientist, Dr. Vitek uses his research findings to inform his treatment of those with PD, as well as uses his patient experiences to inform his research, epitomizing the dual nature that is translational research itself.
My Work
While participating in the work being done by the NMRC, much of my work centers around a project investigating a novel approach to DBS called coordinated reset (CR) DBS. This approach uses patterns of electrical stimulation that differ from traditional models of DBS, using lower currents and providing motor symptom improvements that can persist after stimulation has stopped. As this research itself is relatively new, the project on which I work is also in its infancy. Using NHPs in this research requires their being trained prior to the beginning of actual data collection. The NHP with whom I work is named Beans, a rhesus macaque monkey that weighs in at just under 20 pounds. Much of my work has focused on training her to complete various motor tasks, and once she has mastered these, we can start collecting data from her in the normal state. After this, we will induce in her a Parkinsonian state, where more data collection will occur, and then we will investigate the use of CR DBS in treating her Parkinsonian symptoms in order to optimize this novel treatment option.
Top: An image of a rhesus macaque monkey.
Bottom: An image showing the brain differences between a healthy individual and those with Parkinson's.
Lessons Learned
As a prospective physician-scientist myself, working with the NMRC has provided me with the perfect introduction to translational research, the exact type of research which I also aspire to conduct. I have seen just how much time and effort goes into research, especially translational research which has the potential to make a real difference in the lives of those afflicted. Moreover, working with a non-human primate has made me really think about the ethics at play when using animal models in research. Inducing Parkinson’s in these NHPs and seeing their motor abilities deteriorate as the disease progresses really makes me consider the risks and benefits of using animals in the pursuit of scientific research, especially when using an NHP who has her own personality, her own likes and dislikes, her own social relationships. Furthermore, the social burden of PD and the relative inaccessibility of DBS shows to me another way in which health disparities have become so entrenched in science and medicine. In any case, volunteering at the NMRC has given me experiences and perspectives for which I am incredibly grateful, and I remain excited to continue this work and to see its real-world impacts.
References
Chan, A.K., McGovern, R.A., Brown, L.T., et al. (2014). Disparities in access to deep brain stimulation surgery for Parkinson Disease: Interaction between African American race and Medicaid use. JAMA Neurol, 71(3), 291–299. doi:10.1001/jamaneurol.2013.5798
Parkinson’s Foundation. (n.d.). Statistics. Retrieved from https://www.parkinson.org/Understanding-Parkinsons/Statistics.
Tanner Hubbard
My name is Tanner Hubbard (he/him), a neuroscience major with a community and global health concentration and minors in biology, psychology, and chemistry. While at Macalester, I spent my four years as a member of varsity swimming and diving team, where I was a captain for my junior and senior years. After graduation, I plan to take a gap year to continue working at the NMRC as a researcher before pursuing an MD/PhD.
Image Credits:
https://www.health.umn.edu/research/biomedical-discovery-district/lions-research-building-mcguire-translational-research-facility
https://www.medicalnewstoday.com/articles/covid-19-vaccine-successfully-protects-macaques-against-virus
https://eliteayurveda.com/blog/parkinsons-disease-and-deep-brain-stimulation/
https://www.bbc.com/news/health-48691633
https://www.drprempillay.org/brain/parkinsons-disease/