title: Label-free imaging of membrane potential using membrane electromotility.
abstract: Electrical activity may cause observable changes in a cell's structure in the absence of exogenous reporter molecules. In this work, we report a low-coherence interferometric microscopy technique that can detect an optical signal correlated with the membrane potential changes in individual mammalian cells without exogenous labels. By measuring milliradian-scale phase shifts in the transmitted light, we can detect changes in the cells' membrane potential. We find that the observed optical signals are due to membrane electromotility, which causes the cells to deform in response to the membrane potential changes. We demonstrate wide-field imaging of the propagation of electrical stimuli in gap-junction-coupled cell networks. Membrane electromotility-induced cell deformation may be useful as a reporter of electrical activity.
authors: G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. seungeun_oh@hms.harvard.edu
authors: Seungeun
authors: S
authors: Oh
authors: Christopher
authors: C
authors: Fang-Yen
authors: Wonshik
authors: W
authors: Choi
authors: Zahid
authors: Z
authors: Yaqoob
authors: Dan
authors: D
authors: Fu
authors: YongKeun
authors: Y
authors: Park
authors: Ramachandra R
authors: RR
authors: Dassari
authors: Michael S
authors: MS
authors: Feld
mesh_terms: D000200:Action Potentials; D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D054351:Electrical Synapses / Q000502:physiology / Q000648:ultrastructure; D057809:HEK293 Cells; D006801:Humans; D008857:Microscopy, Interference; D057054:Molecular Imaging; D055620:Optical Phenomena; D018408:Patch-Clamp Techniques