AUTHOR=Akkin Taner , Landowne David , Sivaprakasam Aarthi 

TITLE=Detection of neural action potentials using optical coherence tomography: intensity and phase measurements with and without dyes

JOURNAL=Frontiers in Neuroenergetics

VOLUME=Volume 2 - 2010

YEAR=2010

URL=https://www.frontiersin.org/journals/neuroenergetics/articles/10.3389/fnene.2010.00022

DOI=10.3389/fnene.2010.00022

ISSN=1662-6427

ABSTRACT=We review the use of optical coherence tomography (OCT) for detection of neural activity, and present a new approach for depth localization of neural action potentials using voltage sensitive dyes as contrast agents in OCT.  A stained squid giant axon is imaged by spectral domain OCT.  Changes in the intensity and phase of back-scattered light coming from regions around the membrane are measured during action potential propagation.  The depth-resolved change in back-scattered intensity coincides with the arrival of action potential at the measurement area, and is synchronous with the changes in transmitted light intensity and reflection mode cross-polarized light intensity measured independently.  The system also provides depth-resolved phase changes as an additional indication of activity. With further investigation our results could open a new era in functional imaging technology to localize neural activity at different depths in situ.