Stimulated Raman voltage imaging for quantitative mapping of membrane potential

Voltage imaging has become an emerging technique to record membrane potential change in living cells. Yet, compared to electrophysiology, microscopy approaches are still limited to relative membrane voltage changes, lacking important information conveyed by absolute membrane voltage. This talk will cover a spectroscopy approach to tackle this challenge. A spectroscopic signature of membrane potential was identified through stimulated Raman scattering (SRS) imaging, which enabled label-free, sub-cellular voltage imaging of mammalian neurons. We employed pre-resonance electronic absorption to enhance SRS imaging sensitivity and specificity. microbial rhodopsin voltage sensors, providing a quantitative approach to measure membrane potential. Quantitative voltage imaging by SRS has enabled mapping of absolute voltage in a neural network and has great potential in neurology and brain sciences.