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Inverse-response Ca²⁺ indicators for optogenetic visualization of neuronal inhibition.

ABSTRACT: We have developed a series of yellow genetically encoded Ca²⁺ indicators for optical imaging (Y-GECOs) with inverted responses to Ca²⁺ and apparent dissociation constants (K_d') ranging from 25 to 2400?nM. To demonstrate the utility of this affinity series of Ca²⁺ indicators, we expressed the four highest affinity variants (K_d's?=?25, 63, 121, and 190?nM) in the Drosophila medulla intrinsic neuron Mi1. Hyperpolarization of Mi1 by optogenetic stimulation of the laminar monopolar neuron L1 produced a decrease in intracellular Ca²⁺ in layers 8-10, and a corresponding increase in Y-GECO fluorescence. These experiments revealed that lower K_d' was associated with greater increases in fluorescence, but longer delays to reach the maximum signal change due to slower off-rate kinetics.

SUBMITTER: Zhao Y

PROVIDER: S-EPMC6079023 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Inverse-response Ca2+ indicators for optogenetic visualization of neuronal inhibition.

Zhao Yufeng Y Bushey Daniel D Zhao Yongxin Y Schreiter Eric R ER Harrison D Jed DJ Wong Allan M AM Campbell Robert E RE

Scientific reports 20180806 1

We have developed a series of yellow genetically encoded Ca2+ indicators for optical imaging (Y-GECOs) with inverted responses to Ca2+ and apparent dissociation constants (Kd') ranging from 25 to 2400 nM. To demonstrate the utility of this affinity series of Ca2+ indicators, we expressed the four highest affinity variants (Kd's = 25, 63, 121, and 190 nM) in the Drosophila medulla intrinsic neuron Mi1. Hyperpolarization of Mi1 by optogenetic ...[more]

PMID: 30082904

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