Like players of a life-size video game, scientists can control the movements of rats from up to 500 meters away, according to a new study. The findings, published today in Nature, could lead to the development of robo-rodents capable of carrying out dangerous surveillance missions.

Instead of relying on the typical training regime in which an animal is taught to perform a task in order to receive a reward, Sanjiv Talwar of the State University of New York Downstate Medical Center and his colleagues stimulated areas of the rats' brains in order to control them. They implanted electrodes in two areas of the rodents' brains--one that processes signals from their whiskers and another that processes rewards--and created virtual cues and rewards to manipulate the animals' behavior. Wires from the implants ran to remote-controlled stimulators contained in backpacks worn by the rats. The researchers first placed the rodents in a tight figure-eight course and administered electric pulses to navigate them through the maze, stimulating the brain's reward center to reinforce correct behavior. When the animals were then placed in an open environment, the scientists could still guide their movements.

Of particular interest is the finding that the remote control commands could convince the animals to explore areas that they should instinctively avoid, such as brightly lit, open arenas. The team also maneuvered the rodents through collapsed piles of concrete rubble. "Combined with electronic sensing and navigation technology," the authors conclude, "a guided rat can be developed into an effective 'robot' that will possess several natural advantages over current mobile robots."