An Input/Output Device for the Brain - Made of Light, Algae, and Bacteria

Algae and Light Help Injured Mice Walk Again

• By Michael Chorost
• October 19, 2009 |
• 3:00 pm |
• Wired Nov 2009

In the summer of 2007, a team of Stanford graduate students dropped a mouse into a plastic basin. The mouse sniffed the floor curiously. It didn’t seem to care that a fiber-optic cable was threaded through its skull. Nor did it seem to mind that the right half of its motor cortex had been reprogrammed.

One of the students flipped a switch and intense blue light shone through the cable into the mouse’s brain, illuminating it with an eerie glow. Instantly, the mouse began running in counterclockwise circles as though hell-bent on winning a murine Olympics.

Then the light went off, and the mouse stopped. Sniffed. Stood up on its hind legs and looked directly at the students as if to ask, “Why the hell did I just do that?” And the students whooped and cheered like this was the most important thing they’d ever seen.

Because it was the most important thing they’d ever seen. They’d shown that a beam of light could control brain activity with great precision. The mouse didn’t lose its memory, have a seizure, or die. It ran in a circle. Specifically, a counterclockwise circle.

Precision, that was the coup. Drugs and implanted electrodes can influence the brain, but they are terribly imprecise: Drugs flood the brain and affect many types of neurons indiscriminately. Electrodes activate every neuron around them.

READ MORE: http://www.wired.com/magazine/2009/10/mf_optigenetics/all/1