Dye-Based Fluorescent Organic Nanoparticles, New Promising Tools for Optogenetics.

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Neuroscience

Background:

• Dye-based fluorescent organic nanoparticles are synthesized via nanoprecipitation of pure dyes.
• Their photophysical and colloidal properties depend on dye aggregation.
• Their brightness and near-infrared emission make them suitable for in vivo applications.

Purpose of the Study:

• To investigate the use of dye-based fluorescent organic nanoparticles for in vivo optogenetics.
• To demonstrate their photophysical properties, biocompatibility, and ability to activate Chrimson opsin.
• To present an example of their application in modulating fear responses.

Main Methods:

• Nanoparticle synthesis through nanoprecipitation.
• Characterization of photophysical properties and biocompatibility.
• In vivo optogenetic stimulation using fluorescence reabsorption to activate Chrimson opsin.
• Closed-loop stimulation for fear response modulation in mice.

Main Results:

• Demonstrated photophysical properties and biocompatibility of the nanoparticles.
• Confirmed activation of Chrimson opsin in vivo via fluorescence reabsorption.
• Successfully reduced fear responses in mice by selectively manipulating fear-related neurons.
• Showcased the nanoparticles' potential in a closed-loop optogenetic system.

Conclusions:

• Dye-based fluorescent organic nanoparticles are a versatile platform for in vivo optogenetics.
• These nanoparticles can effectively activate opsins and modulate neural circuits.
• This approach holds significant promise for translational neuroscience and treating neurological disorders.