RT Journal Article
SR Electronic
T1 Diminishing neuronal acidification by channelrhodopsins with low proton conduction
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2023.02.07.527404
DO 10.1101/2023.02.07.527404
A1 Rebecca Frank Hayward
A1 F. Phil Brooks III
A1 Shang Yang
A1 Shiqiang Gao
A1 Adam E Cohen
YR 2023
UL http://biorxiv.org/content/early/2023/02/08/2023.02.07.527404.abstract
AB Many channelrhodopsins are permeable to protons. We found that in neurons, activation of a high-current channelrhodopsin, CheRiff, led to significant acidification, with faster acidification in the dendrites than in the soma. Experiments with patterned optogenetic stimulation in monolayers of HEK cells established that the acidification was due to proton transport through the opsin, rather than through other voltage-dependent channels. We identified and characterized two opsins which showed large photocurrents, but small proton permeability, PsCatCh2.0 and ChR2-3M. PsCatCh2.0 showed excellent response kinetics and was also spectrally compatible with simultaneous voltage imaging with QuasAr6a. Stimulation-evoked acidification is a possible source of disruptions to cell health in scientific and prospective therapeutic applications of optogenetics. Channelrhodopsins with low proton permeability are a promising strategy for avoiding these problems.Statement of Significance Acidification is an undesirable artifact of optogenetic stimulation. Low proton-permeability opsins minimize this artifact while still allowing robust optogenetic control.Competing Interest StatementThe authors have declared no competing interest.