Ultrafast light targeting for high-throughput precise control of neuronal networks.

Area of Science:

• Neuroscience
• Optogenetics
• Optical Engineering

Background:

• Current holographic optogenetics offers precise spatiotemporal control of neuronal activity for applications like connectivity mapping.
• Existing methods are limited to millisecond-scale temporal resolution and 100-200 cell targets, restricting complex neural ensemble studies.

Purpose of the Study:

• To overcome limitations in current holographic optogenetics by enhancing temporal resolution and target capacity.
• To introduce an advanced optical configuration for precise, high-throughput single-cell optogenetics.

Main Methods:

• Developed an ultra-fast sequential light targeting (FLiT) optical configuration utilizing rapid switching of a temporally focused beam between holograms at kHz rates.
• Demonstrated hybrid- and cyclic-illumination protocols for sub-millisecond control of sequential neuronal activation and multicell illumination.
• Validated FLiT in vitro (mouse organotypic and acute brain slices) and in vivo (zebrafish larvae and mice), monitoring light-induced thermal effects.

Main Results:

• Achieved sub-millisecond control over sequential neuronal activation, significantly improving temporal precision beyond current holographic methods.
• Enabled high-throughput multicell illumination, expanding the number of simultaneously controllable neurons.
• Demonstrated minimal light-induced thermal rise, ensuring cell viability during stimulation.

Conclusions:

• The FLiT configuration provides unprecedented temporal resolution and scalability for single-cell optogenetics.
• This technology is crucial for experiments demanding rapid, precise stimulation of neuronal ensembles with defined spatio-temporal patterns.
• FLiT advances the capabilities for probing neural codes and understanding complex brain functions.