microLED Neural Probes to Study Brain Activity in Living Animals


Optogenetics is a fast evolving technique that allows scientists to activate specific neurons within the brains of living laboratory animals using flashes of light. It may also be effective at recovering sight, as well as achieving other impressive feats (see flashbacks below).

To best study and manipulate complex brain activity using optogenetics, particularly activity that occurs over time such as memory, one has to be able to stimulate and immediately sense what the surrounding neurons are doing. The hurdle has been the fact that the very device that initiates the light flashes that make neurons fire creates too much noise for the receiving electrodes to sense the immediate responses that nearby neurons generate.

Now, researchers at the University of Michigan, who developed the tiniest light sources on implantable brain electrodes about five years ago, which are small enough to activate single neurons, have demonstrated a way to prevent these microLEDs from creating almost any interference for the sensing electrodes. The trick was to add boron to the silicon electrodes, improving their conductivity and reducing susceptibility to interference, as well as using electric shielding.

Thanks to this development, researchers will be able to stimulate individual neurons, or select groups of neurons, and immediately see the corresponding actions that the brain takes, potentially leading to an improved understanding of memory, decision making, and various diseases, as well as how to address many neurological medical challenges.

Flashbacks: Tiny LED Implants for Controlling and Studying Activity of Individual Neurons; Wireless Implants Allow Optogenetic Control of Animal Behavior Without a Tether; Generating Hallucinations Using Optogenetics; Advanced Wireless and Battery-Free Optogenetics Device to Control Neuronal Activation; Optogenetic Brain System to Give Blind People Sight

Study in Nature Communications: Artifact-free and high-temporal-resolution in vivo opto-electrophysiology with microLED optoelectrodes

Via: University of Michigan

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