Neurotransmitter sensing is important for both fundamental understanding and clinical treatment of many diseases and conditions, including Alzheimer’s disease, obsessive-compulsive disorder, depression, and drug addiction, which not only create a huge economic burden in our society but also induce enormous negative impact in the life quality of affected people and their families. Neurochemical sampling has long been performed by micro-dialysis. More recently, fiber photometry-based optical sensing of neuromodulators has enabled high spatiotemporal resolution in vivo. However, both methods have significant limitations in human translation.
Fast-scan cyclic voltammetry (FSCV) possesses cellular and sub-second resolutions and has revealed the details and influence of dynamics of multiple neuromodulators, such as dopamine and serotonin, in both animals and humans. However, carbon fiber electrodes (CFEs), the mainstay device for FSCV, are fragile and difficult to make and scale up for high spatial resolution. Great strides have been made to create alternative carbon electrodes to replace conventional carbon fiber electrodes from carbonization strategies such as pyrolyzed polymers and laser-induced graphitization, but they are limited to pyrolysis-based processes with prohibitively high temperatures, which impede their incorporation into electrodes currently used in the human brain, which are mostly polymer based. Despite tremendous progress in in vivo neurotransmitter sensing, there are no available medical devices that can sense neurotransmitters within the living human brain.
In collaboration with Hui Fang (Dartmouth College), Jay Leiter (WRJ VAMC), and NeuroOne, we are working to fill this important gap by translating recent neural FSCV sensor innovation. We are translating a novel approach to carbon coating to create electrodes implantable in humans with high electrochemical stability and excellent FSCV performance. We are working on extensive pre-clinical testing and development towards first-in-human applications within a five years. Our long-term goal is to shift the current paradigm of neurophysiological monitoring and recording from electrophysiology only to electrophysiology combined with chemical sensing by integrating interoperable neurotransmitter sensors.