Mouse Runs on Trackball Through Virtual Maze

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Princeton neuroscientist David Tank wanted to study individual neurons in a mouse's hippocamus as it moves. But the movement of the mouse's body prevented accurate readings. So he placed the mouse on a giant trackball and let it run through a virtual maze from the video game Quake 2 displayed on screens. Brandon Keim writes in Wired:

Studying individual neurons has been possible in cell cultures, but brains in a dish behave different than real, living brains. Tracking individual neurons in moving animals has been impossible.

“The neurons move back and forth while you’re trying to measure things,” said Tank. “So we developed a way to keep the head fixed in space, but still have mice perform behaviors that are usually studied in mice running through a maze.”

Tank’s team designed an apparatus in which a mouse, its head firmly held in a metal helmet, walks on the surface of a styrofoam ball. The ball is kept aloft by a jet of air, so that it functions like a multidirectional treadmill. Around it are sensors taken from optical computer mice, which read the ball’s movement as the mouse runs.

Those readings were the input for the researchers’ virtual reality software — a modified version of the open source Quake 2 videogame engine, tweaked to project an image on a screen surrounding the mouse. Tank called it “a mini-IMAX theater.”

Link via Popular Science