AUTHOR=Ahrens Kurt F., Heider Barbara , Lee Hanson , Isacoff Ehud Y., Siegel Ralph M.

TITLE=Two-photon scanning microscopy of in vivo sensory responses of cortical neurons genetically encoded with a fluorescent voltage sensor in rat

JOURNAL=Frontiers in Neural Circuits

VOLUME=6

YEAR=2012

URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2012.00015

DOI=10.3389/fncir.2012.00015

ISSN=1662-5110

ABSTRACT=<p>A fluorescent voltage sensor protein “Flare” was created from a Kv1.4 potassium channel with YFP situated to report voltage-induced conformational changes <italic>in vivo</italic>. The RNA virus Sindbis introduced Flare into neurons in the binocular region of visual cortex in rat. Injection sites were selected based on intrinsic optical imaging. Expression of Flare occurred in the cell bodies and dendritic processes. Neurons imaged <italic>in vivo</italic> using two-photon scanning microscopy typically revealed the soma best, discernable against the background labeling of the neuropil. Somatic fluorescence changes were correlated with flashed visual stimuli; however, averaging was essential to observe these changes. This study demonstrates that the genetic modification of single neurons to express a fluorescent voltage sensor can be used to assess neuronal activity <italic>in vivo.</italic></p>