Understanding how a network of interconnected neurons receives, stores and processes information in the human brain is one of the greatest scientific challenges of our time. Neurons encode information by electrical signals. Optical detection and imaging of electric activities provide unprecedented flexibility and parallelization.<b> </b>In the last decade, the advancement of voltage-sensitive fluorescent proteins, and small potentiometric dyes, has drastically enhanced the capability optical recording of electrical activity in cells. However, the use of fluorescence proteins requires genetic modification of the cells and the membrane insertion of voltage-sensitive probes can lead to membrane capacitance loading. The fluorescence-based imaging approach also suffers from phototoxicity, limited signal-to-noise, limited recording duration due to photobleaching, and time-dependent probe internalization and protein expression. We develop a novel technique to detect electric activities of a neuronal network in a label-free, parallel and non-invasive manner. Our detection technique exploits unique physical properties of electrochromic materials, whose optical properties can be modulated by the applied electric potential. Combined with sensitive optical detection, our method is able to achieve label-free detection of action potentials in neurons, cardiomyocytes, engineered spiking-HEK cells and brain slices over long periods of time.

Label-free optical detection of neural electric potentials

2019 Fall National Meeting

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