Related Experiment Video
Updated: May 20, 2026
09:57
Imaging Membrane Potential with Two Types of Genetically Encoded Fluorescent Voltage Sensors
Published on: February 4, 2016
Label-free imaging of membrane potential using membrane electromotility
Seungeun Oh1, Christopher Fang-Yen, Wonshik Choi
1G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. seungeun_oh@hms.harvard.edu
Biophysical Journal
|July 26, 2012
Summary
This study introduces a label-free microscopy method to optically detect cellular electrical activity. The technique visualizes membrane electromotility, revealing cell deformation linked to membrane potential changes.
Area of Science:
- Biophysics
- Cell Biology
- Optical Microscopy
Background:
- Cellular electrical activity, such as changes in membrane potential, can influence cell structure.
- Detecting these structural changes typically requires exogenous reporter molecules, limiting real-time observation.
- A label-free method is needed to optically monitor electrical activity in living cells.
Purpose of the Study:
- To develop and demonstrate a low-coherence interferometric microscopy technique for label-free detection of cellular electrical activity.
- To correlate optical signals with changes in cell membrane potential.
- To investigate the underlying mechanism of the observed optical signal.
Main Methods:
- Utilized low-coherence interferometric microscopy to measure milliradian-scale phase shifts in transmitted light.
- Applied the technique to individual mammalian cells to detect membrane potential changes without exogenous labels.
- Performed wide-field imaging of electrical stimuli propagation in gap-junction-coupled cell networks.
Main Results:
- Successfully detected optical signals correlated with membrane potential changes in individual mammalian cells.
- Identified membrane electromotility as the cause of cell deformation in response to electrical activity.
- Demonstrated imaging of electrical stimulus propagation across coupled cell networks.
Conclusions:
- A label-free interferometric microscopy technique can detect cellular electrical activity through membrane electromotility.
- Cell deformation induced by membrane electromotility serves as a reporter for electrical activity.
- This method offers a novel approach for studying electrical signaling in cellular systems.
Related Concept Videos
01:21The Resting Membrane Potential
Overview
01:15Potentiometry: Membrane Electrodes
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
01:24Resting Membrane Potential
The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...