Dopamine neurochemicals govern important behaviors (e.g. movement and motivation) that are differentially impaired in many pathological conditions including Parkinson’s disease and mood disorders. There has been a disparaging absence of tools to chronically measure these important chemicals in the brains of nonhuman primates—animals that closely emulate the complex human neuroanatomy and behaviors. I will present techniques to longitudinally probe neurochemical activity in awake behaving primates, with the goal of clinical translation. Such long-term capabilities are critical to improve diagnostic and therapeutic procedures for a wide range of neurological disorders.
With my skilled colleagues in the laboratories of Dr. Cima and Dr. Graybiel, we developed integrated platforms that allow multi-modal (electrical and chemical) and multi-site interrogation of the deep brain basal ganglia circuits that heavily engage a number of neurotransmitters, including dopamine. These neurotransmitter systems control key movement and mood behaviors that become compromised in many debilitating neural disorders. I will describe the application of our modular platforms in tracking dopamine neurotransmission over months-long time periods in primates. We further developed the smallest chemical probes with diameters less than 10 microns. The cellular-scale dimensions of our probes helped combat inflammation and scarring responses of the implanted brain tissue environment that usually impede reliable chemical detection. These micro-invasive features enhance the longevity of chemical recording functions and maximize safety of these implants towards clinical use. We further fabricated these sensors in the form of arrays to monitor dopamine from many different sites in the brain. I will present preliminary multi-site measurements of dopamine release in rodents.
Finally, I will describe my vision towards multi-modal brain interrogation to extrapolate the diverse neural electrical and chemical dynamics that are integrated to mediate all aspects of our behavior.
Helen Schwerdt received the B.S in biomedical engineering and M.S.E in electrical and computer engineering from Johns Hopkins University in 2008 and 2009, respectively, and the Ph.D in electrical engineering from Arizona State University in 2014. She was a recipient of the NASA Graduate Student Research Program fellowship to support her Ph.D on wireless backscattering microsystems for recording neural activity. Helen now works as a postdoctoral fellow in the laboratories of Dr. Michael Cima and Dr. Ann Graybiel at MIT. She aims to integrate medical device technology and neuroscience to develop translational tools for improving treatment of debilitating neurological disorders including Parkinson’s disease and mood disorders. She was awarded the NIH Ruth L. Kirschstein National Research Service Award in 2015 to support her studies. Helen’s long-term goals are to improve treatment of brain disorders through micro-invasive interfaces and to resolve the electrical and chemical basis of these disorders using multi-modal technologies.