Seeing the sound: novel optical and ultrasonic methods for neuromodulation

Abstract Today’s optical neuromodulation methods enable causal manipulation of neural activity with light to dissect complex circuit connections underlying certain behaviors. In these optical neuromodulation approaches, visible light with wavelengths between 430 nm and 640 nm is commonly used, thus limiting penetration depth in vivo and resulting in an invasive fiber-tethered interface that damages the endogenous neural tissue and constrains the animal’s free behavior. In this talk, I will present two recent methods to address this challenge via novel optical and ultrasonic brain interfaces: sono-optogenetics and infrared optogenetics. In sono-optogenetics, we demonstrate that mechanoluminescent nanoparticles can act as a systemic light source to convert focused ultrasound into localized light emission for noninvasive optogenetic neuromodulation in live mice. In infrared optogenetics, we demonstrate 1064-nm near-infrared-II light can enable tether-free and implant-free neuromodulation throughout the entire brain in freely behaving mice. I will conclude my talk by presenting an outlook on how these approaches may advance neuroscience research in live animals and even humans. Research Category and Technology and Methods Basic Research: 13. Other Brain Stimulation Technology Keywords: Sono-optogenetics, TRP channels, mechanoluminescence, infrared