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bioRxiv · 10.64898/2026.07.17.739178

Mapping absolute membrane voltage using dynamic photocycle control

Gong, D.·Zhang, J.·Howell, M. R.·Wu, X.·Jia, B. Z.·Cohen, A. E.
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Abstract

Fluorescent voltage indicators are widely used to report relative changes in membrane potential, but mapping absolute voltages remains difficult. Here we present Voltage Measurement by Activated Photocycles (VMAP), a simple method for absolute voltage imaging based on a photophysical switch between voltage-insensitive and sensitive indicator states. VMAP requires no specialized hardware or additional labeling, and is applicable across species, sample preparations, and microscope configurations. Using VMAP, we quantified drug-induced shifts in neuronal resting potential, revealed the emergence of bioelectric patterns during multi-day recordings of human iPSC populations, and created 3D membrane-potential maps across whole live zebrafish embryos. By making absolute voltage imaging accessible from cellular to organismal scales and from milliseconds to days, VMAP opens a route to mapping bioelectrical organization in complex living systems.

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Gong, D., Zhang, J., Howell, M. R., Wu, X., Jia, B. Z., Cohen, A. E.. 2026-07-17. Mapping absolute membrane voltage using dynamic photocycle control. https://doi.org/10.64898/2026.07.17.739178

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