Near-infrared deep brain stimulation via upconversion nanoparticle–mediated optogenetics

TLDR

Deep brain stimulation is a key goal in neuroscience, yet conventional optogenetics requires invasive blue lasers inserted into the brain. The authors used upconversion nanoparticles that convert externally applied near‑infrared light into local blue emission, injecting them into the ventral tegmental area to activate channelrhodopsin in dopaminergic neurons. Near‑infrared stimulation via the nanoparticles rapidly increased dopamine release and successfully induced fear memories in the dentate gyrus during conditioning. The study is reported in Science, issue p.

Abstract

Stimulating deep inside the brain Noninvasive deep brain stimulation is an important goal in neuroscience and neuroengineering. Optogenetics normally requires the use of a blue laser inserted into the brain. Chen et al. used specialized nanoparticles that can upconvert near-infrared light from outside the brain into the local emission of blue light (see the Perspective by Feliu et al. ). They injected these nanoparticles into the ventral tegmental area of the mouse brain and activated channelrhodopsin expressed in dopaminergic neurons with near-infrared light generated outside the skull at a distance of several millimeters. This technique allowed distant near-infrared light to evoke fast increases in dopamine release. The method was also used successfully to evoke fear memories in the dentate gyrus during fear conditioning. Science , this issue p. 679 ; see also p. 633