Samuel Brunwasser

Program: Neurosciences

Current advisor: Keith B. Hengen, PhD

Undergraduate university: Arizona State University Tempe

Research summary
Understanding how complex behavior is encoded by the brain is a major goal of systems neuroscience. Many studies suggest that the brain encodes behavior in a low number of dimensions despite the large number of neurons present. Importantly, these studies all rely on task paradigms in which behavior is highly constrained, such as during head-fixed reaching tasks. However, in natural environments the brain is tasked with orchestrating rich sequences of unconstrained behavior. Thus, it remains to be determined if the brain can encode unconstrained behavior in low dimensions as well. To address this question, I utilize high channel count in vivo electrophysiology to continuously monitor the activity of single neurons in mouse motor cortex during several days of free home-cage behavior. Additionally, I quantify natural behavior using machine vision tools. Through pairing these techniques, I quantify the neural dynamics surrounding specific natural behaviors such as drinking, as well as the neural dimensionality necessary to produce the large repertoire of natural behaviors exhibited over a chronic timespan. Understanding the representation of complex natural behavior across many neurons will be critical for reliably interpreting and controlling brain activity during free behavior, as is the goal for therapies such as brain-computer interfaces and deep brain stimulation.

Graduate publications
Chisari M, Wilding TJ, Brunwasser S, Krishnan K, Qian M, Benz A, Huettner JE, Zorumski CF, Covey DF, Mennerick S. 2019 Visualizing pregnenolone sulfate-like modulators of NMDA receptor function reveals intracellular and plasma-membrane localization. Neuropharmacology, 144():91-103.

Warikoo N, Brunwasser SJ, Benz A, Shu HJ, Paul SM, Lewis M, Doherty J, Quirk M, Piccio L, Zorumski CF, Day GS, Mennerick S. 2018 Positive Allosteric Modulation as a Potential Therapeutic Strategy in Anti-NMDA Receptor Encephalitis. J Neurosci, 38(13):3218-3229.