PinkyCaMP a mScarlet-based calcium sensor with exceptional brightness, photostability, and multiplexing capabilities.

Area of Science:

• Neuroscience
• Molecular Biology
• Biophysics

Background:

• Genetically encoded calcium indicators (GECIs) are crucial for visualizing neuronal activity.
• Existing red fluorescent GECIs suffer from dim fluorescence, low signal-to-noise ratios, and photoswitching issues, limiting their use.
• These limitations hinder advanced optical imaging techniques and optogenetics.

Purpose of the Study:

• To develop a superior red fluorescent genetically encoded calcium indicator.
• To overcome the limitations of current red-shifted GECIs, particularly photoswitching.
• To create a versatile sensor compatible with various advanced imaging modalities.

Main Methods:

• Development of a novel mScarlet-based calcium sensor, named PinkyCaMP.
• Characterization of PinkyCaMP's fluorescence properties, including brightness, photostability, and signal-to-noise ratio.
• Assessment of PinkyCaMP's performance and biocompatibility in vitro and in vivo using various imaging techniques.

Main Results:

• PinkyCaMP demonstrates enhanced brightness, photostability, and signal-to-noise ratio compared to existing red fluorescent sensors.
• The sensor is well-tolerated by neurons, exhibiting no toxicity or aggregation.
• PinkyCaMP is compatible with diverse imaging methods, including fiber photometry, widefield, miniscope, and two-photon imaging in awake mice.

Conclusions:

• PinkyCaMP represents a significant advancement in red fluorescent genetically encoded calcium indicators.
• Its superior performance and broad compatibility make it a valuable tool for neuroscience research.
• PinkyCaMP facilitates advanced optical imaging and optogenetic experiments with red fluorescence.