Sustained deep-tissue voltage recording using a fast indicator evolved for two-photon microscopy.

Area of Science:

• Neuroscience
• Biotechnology
• Microscopy

Background:

• Genetically encoded voltage indicators (GEVIs) are crucial for cell-type-specific voltage dynamics monitoring.
• Current GEVIs exhibit limitations in performance, particularly under two-photon microscopy, hindering deep-tissue neural recordings.

Purpose of the Study:

• To optimize GEVIs for enhanced performance with two-photon microscopy.
• To develop a novel GEVIs, JEDI-2P, with improved speed, brightness, sensitivity, and photostability.

Main Methods:

• Development of a multiparameter high-throughput platform for GEVIs optimization.
• Application of the platform to identify and characterize JEDI-2P.
• In vivo and ex vivo validation of JEDI-2P in Drosophila, mouse retina, and awake behaving mice.

Main Results:

• JEDI-2P demonstrates superior speed, brightness, sensitivity, and photostability compared to existing indicators.
• Successfully reported light-evoked responses in Drosophila interneurons and mouse retinal amacrine cells.
• Enabled long-term optical recording of individual cortical neurons in awake mice using resonant-scanning and ULoVE microscopy.
• ULoVE recording with JEDI-2P detected spikes at depths >400 μm and revealed neuronal voltage correlations.

Conclusions:

• JEDI-2P represents a significant advancement in GEVIs for two-photon microscopy.
• This indicator facilitates high-resolution voltage imaging in deep neural circuits.
• JEDI-2P opens new avenues for studying neural circuit function in vivo.