Tetherless Optical Neuromodulation: Wavelength from Orange-red to Mid-infrared

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Optogenetics offers precise neural control but is limited by visible light's shallow tissue penetration.
• Conventional optogenetics requires invasive optical fibers, causing tissue damage and experimental constraints.
• Longer wavelengths (orange-red, infrared) offer greater tissue penetration for improved neuromodulation.

Purpose of the Study:

• To review the development and applications of tetherless optical neuromodulation using long-wavelength light.
• To explore orange-red wavelength-responsive rhodopsins for enhanced neuromodulation.
• To summarize novel near-infrared and mid-infrared neuromodulation techniques.

Main Methods:

• Review of literature on orange-red rhodopsins for optogenetics.
• Summary of upconversion nanoparticle-mediated optogenetics.
• Discussion of photothermal neuromodulation and mid-infrared optogenetics.

Main Results:

• Orange-red rhodopsins show promise for tetherless optical neuromodulation.
• Near-infrared methods like upconversion nanoparticles and photothermal stimulation offer new avenues.
• Mid-infrared optogenetics is an emerging area with recent advancements.

Conclusions:

• Tetherless optical neuromodulation with long wavelengths overcomes key limitations of conventional optogenetics.
• Advanced techniques utilizing orange-red and infrared light enable less invasive and deeper neural interventions.
• This approach holds significant potential for both fundamental neuroscience research and therapeutic applications.