By attaching a microstimulator and geomagnetic compass to the brains of blind rats, Japanese researchers have found that the animals can spontaneously learn to navigate through a maze nearly as well as normally sighted rats. Researchers say the findings suggest that a similar kind of neuroprosthesis might also help blind people walk freely through the world.
The head-mountable geomagnetic sensor device the researchers devised allowed them to connect a digital compass (similar to those in smart phones) to two tungsten microelectrodes for stimulating the visual cortex of the brain.
The very lightweight device also allowed the researchers to turn the brain stimulation up or down and included a rechargeable battery. Once attached, the compass automatically detected the rat’s head direction and generated electrical pulses that indicated which direction, such as north or south, the rat was facing.
The blind rats were then trained to seek food in a T-shaped maze or a more complicated maze. With practice, the rats learned to use the device to solve the mazes, and their performance rivaled that of rats with normal vision.
“We were surprised that rats can comprehend a new sense that had never been experienced or ‘explained by anybody’ and can learn to use it in behavioral tasks within only two to three days,” lead researcher Yuji Ikegaya said in a journal news release.
The findings suggest that a similar system could help orient blind people, said Yuji Ikegaya and his colleague Hiroaki Norimoto, researchers of the University of Tokyo. In the case of humans, the device could be attached to the canes blind people typically use for walking around, the researchers said.
Journal Reference: cell.com/current-biology/abstract