Absolute voltage mapping using dynamic photocycle control

Area of Science:

• Bioelectricity
• Optical Imaging
• Neuroscience

Background:

• Fluorescent voltage indicators commonly measure relative membrane potential changes.
• Accurate mapping of absolute membrane voltages is challenging with current methods.

Purpose of the Study:

• To introduce Voltage Measurement by Activated Photocycles (VMAP) for absolute voltage imaging.
• To demonstrate VMAP's applicability across diverse biological scales and experimental setups.

Main Methods:

• VMAP utilizes a photophysical switch between voltage-insensitive and sensitive indicator states.
• The method requires no specialized hardware or additional labeling.

Main Results:

• Quantified drug-induced shifts in neuronal resting potential.
• Revealed bioelectric patterns in human iPSC populations over multi-day recordings.
• Generated 3D membrane-potential maps of whole live zebrafish embryos.

Conclusions:

• VMAP enables accessible absolute voltage imaging from cellular to organismal levels.
• The technique supports recordings from milliseconds to days.
• VMAP facilitates mapping bioelectrical organization in complex living systems.