Voltage imaging in the olfactory bulb using transgenic mouse lines expressing the genetically encoded voltage...

Area of Science:

• Neuroscience
• Genetics
• Optical Imaging

Background:

• Genetically encoded voltage indicators (GEVIs) enable optical monitoring of membrane potential changes in specific cell populations.
• Developing transgenic animals for precise GEVI expression in vivo is crucial for mammalian brain research.
• Existing literature on transgenic mouse lines for GEVI expression is limited.

Purpose of the Study:

• To report the first in vivo experiments using a transgenic reporter mouse for the GEVI ArcLight.
• To establish and validate transgenic mouse lines for GEVI expression in specific neuronal populations.
• To assess the utility of these lines for in vivo imaging of neuronal activity.

Main Methods:

• Developed two transgenic mouse lines utilizing a Cre/tTA dependent expression system (TIGRE 1.0) for ArcLight GEVI expression.
• Restricted ArcLight expression to olfactory receptor neurons or specific interneurons in the olfactory bulb.
• Performed in vivo imaging of odorant responses using epifluorescence and 2-photon microscopy.

Main Results:

• Demonstrated sufficient ArcLight expression for in vivo imaging of odorant responses in single trials.
• Observed odor-specific and concentration-dependent voltage responses, consistent with previous findings.
• Achieved signal-to-noise ratios comparable to viral transduction methods.

Conclusions:

• The ArcLight transgenic mouse line is a versatile tool for in vivo neuronal electrical activity recording.
• This technology allows for precise targeting and high expression levels of GEVIs in the mammalian brain.
• The developed lines facilitate the study of neuronal function in defined cell types with high fidelity.