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Light-Induced GFP Expression in Zebrafish Embryos using the Optogenetic TAEL/C120 System
Published on: August 19, 2021
Temporal control of immediate early gene induction by light
Philipp Schoenenberger1, Daniela Gerosa, Thomas G Oertner
1Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
Plos One
|December 10, 2009
Summary
A channelrhodopsin-2 (ChR2) mutation (C128A) induces high-frequency neuronal firing and c-fos expression with light. This ChR2 mutant is useful for gene induction but not chronic neural stimulation.
Area of Science:
- Neuroscience
- Optogenetics
- Molecular Biology
Background:
- Channelrhodopsin-2 (ChR2) enables optical control of neuronal activity.
- Mutations at cysteine 128 (C128) extend ChR2's conducting state lifetime.
- Previous C128 mutants only induced subthreshold neuronal depolarizations.
Purpose of the Study:
- To investigate the effects of the ChR2 C128A mutation on neuronal firing and gene expression.
- To assess the potential of ChR2(C128A) for precise neuronal stimulation and gene induction.
Main Methods:
- Transfection of pyramidal cells in hippocampal slice cultures with ChR2(C128A).
- Induction of action potentials and spike trains using brief light pulses.
- Detection of c-fos gene expression via c-Fos protein detection.
Main Results:
- Brief light pulses induced long, high-frequency spike trains in ChR2(C128A)-expressing cells.
- ChR2(C128A)-mediated firing triggered cell-specific c-fos expression.
- Photocurrents diminished with repeated stimulation, limiting sustained firing.
Conclusions:
- ChR2(C128A) is effective for light-controlled induction of immediate early genes like c-fos.
- The C128A mutant is not suitable for chronic neuronal stimulation due to photocurrent rundown.
- This ChR2 mutant allows precise, single-cell control over gene expression under the c-fos promoter.
