We’re used to turning on lights with a switch. But what about switching on other things with a light? Using optogenetics, researchers can shine a point of light at brain cells to activate or inhibit them, revealing crucial details about what’s going on. But there’s a physical limit to this, since you can only really shine a light onto the brain’s surface. To solve this, a new technique makes use of a different type of light, called near-infrared, which passes through body tissue like visible light through glass. Researchers injected a group of nanoparticles (blue) into a mouse brain, which can themselves produce visible light when hit by near-infrared light shone in from the outside. They could then stimulate previously-unreachable brain cells (red dots in the brain section pictured). Early tests successfully triggered memory recall, and the technique could help reveal new treatment options for all sorts of neurological diseases.
Written by Anthony Lewis
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