Erasable labeling of neuronal activity using a reversible calcium marker

Area of Science:

• Neuroscience
• Biochemistry
• Molecular Biology

Background:

• Understanding brain function necessitates recording neural activity linked to behavior.
• Fluorescent protein engineering has yielded tools for visualizing neural activity.
• Reversibly switchable fluorescent proteins offer new possibilities for sensor development.

Purpose of the Study:

• To engineer a novel calcium sensor using reversibly switchable fluorescent proteins.
• To develop a tool for spatiotemporally precise marking and remarking of active neurons.

Main Methods:

• Engineered a genetically encoded calcium marker, rsCaMPARI, from a reversibly switchable fluorescent protein.
• Utilized blue light to modulate rsCaMPARI photoswitching kinetics by calcium concentration.
• Employed violet light to reset fluorescence for remarking active neuron populations.

Main Results:

• rsCaMPARI enables precise marking, erasing, and remarking of active neuron populations.
• Photoswitching kinetics are dependent on calcium concentration and light exposure.
• Demonstrated utility in freely swimming zebrafish for marking neural activity.

Conclusions:

• rsCaMPARI is a powerful new tool for visualizing neural activity with high spatiotemporal precision.
• This sensor allows dynamic tracking and manipulation of neural ensembles.
• Opens new avenues for studying neural circuits underlying behavior.