Transient, Consequential Increases in Extracellular Potassium Ions Accompany Channelrhodopsin2 Excitation.

ABSTRACT: Channelrhodopsin2 (ChR2) optogenetic excitation is widely used to study neurons, astrocytes, and circuits. Using complementary approaches in situ and in vivo, we found that ChR2 stimulation leads to significant transient elevation of extracellular potassium ions by ∼5 mM. Such elevations were detected in ChR2-expressing mice, following local in vivo expression of ChR2(H134R) with adeno-associated viruses (AAVs), in different brain areas and when ChR2 was expressed in neurons or astrocytes. In particular, ChR2-mediated excitation of striatal astrocytes was sufficient to increase medium spiny neuron (MSN) excitability and immediate early gene expression. The effects on MSN excitability were recapitulated in silico with a computational MSN model and detected in vivo as increased action potent

SUBMITTER: Octeau JC 

PROVIDER: S-EPMC6582980 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature