Measuring Absolute Membrane Potential Across Space and Time

Membrane potential (V-mem) is a fundamental biophysical signal present in all cells. V-mem signals range in time from milliseconds to days, and they span lengths from microns to centimeters. V-mem affects many cellular processes, ranging from neurotransmitter release to cell cycle control to tissue patterning. However, existing tools are not suitable for V-mem quantification in many of these areas. In this review, we outline the diverse biology of V-mem, drafting a wish list of features for a V-mem sensing platform. We then use these guidelines to discuss electrode-based and optical platforms for interrogating V-mem. On the one hand, electrode-based strategies exhibit excellent quantification but are most effective in short-term, cellular recordings. On the other hand, optical strategies provide easier access to diverse samples but generally only detect relative changes in V-mem. By combining the respective strengths of these technologies, recent advances in optical quantification of absolute V-mem enable new inquiries into V-mem biology.

Automated summary

Membrane potential is a fundamental biophysical signal present in all cells, affecting various cellular processes. Existing tools are not yet suitable for accurate quantification of membrane potential in different areas. Electrode-based and optical platforms are the two main technologies for interrogating membrane potential, each with its own strengths and limitations, but combining them can lead to new inquiries into membrane potential biology.