Picture this: there’s been an earthquake and you’re trapped in the rubble. In the dark you hear a scrabbling sound…and feel the long, naked tail of a rat slither across your cheek…
Sounds like a nightmare, doesn’t it? But if recent research bears fruit, it may be a dream come true–because that rat could be a remote-controlled rescue rat.
Last week’s issue of Nature contained details of experiments carried out at the State University of New York and Drexel University in Philadelphia in which, by surgically implanting three electrical probes into the brains of rats, researchers were able to remotely control the rat’s actions from up to 500 metres away.
Researchers have been experimenting with electronic animal control for decades. In the 1960s, Jose Delgado, a Yale physiologist, wired an electrode into the brain of a bull. As the bull charged him, he flicked a switch on a transmitter–and the bull stopped, turned, and walked quietly away.
In the same decade, the CIA spent $14 million developing Acoustic Kitty, a cat with a microphone surgically implanted in its gut and a navigating antenna in its tail. Alas, Acoustic Kitty was run over and killed during its first test mission.
More recent experiments have included a two-wheeled robot operated partly on the electrical signals from the displaced brain of a lamprey, robotic arms controlled solely by brain signals from rats and monkeys, and a cockroach fitted with a micro-robotic backpack to control its movements, developed at Tokyo University.
In the remote-controlled rat experiment, each of five rats was fitted with two probes to its brain that triggered sensations similar to what the rat would feel if something touched its right or left whiskers. The third probe went to the medial forebrain bundle, or MFB, which, when stimulated, sends the rat a feeling reward. The probes ran to a backpack on the rat’s back, which contained an antenna and a remote-controlled stimulator.
The rats were first trained in a maze. When the left-whisker or right-whisker probe was stimulated, and the rats turned in that direction, they were rewarded with a pulse to the MFB. Applying a pulse to the MFB alone, the researchers found, caused the rats to continue moving forward. Essentially, they were trained the way rats have always been trained, except the reward was direct stimulation of the brain instead of food.
Once the rats were taken out of the maze, they continued to obey the turn-left, turn-right commands, issued from a laptop computer using either key commands or a joystick. Researchers were able to guide the rats up ladders, down stairs and across narrow ledges; even up and down trees, though the rats had never been outside before.
Funding came from the U.S. Department of Defence, and was partly inspired by search-and-rescue efforts after the September 11 terrorist attacks. Robots are sometimes used in search-and-rescue efforts, but no robot can traverse difficult terrain as well as a rat or penetrate the tiny spaces rats can penetrate. Equipped with tiny video cameras, remote-controlled rats could become valuable tools for finding trapped people.
There are problems to be resolved. Cameras attached to the test rats returned video too jerky to be of much use. Another problem would be knowing when the rats found something. You’d also have to be able to pinpoint the rat’s location. Loss of signal could be a problem, too, although it might be possible to create a wireless computer network to ferry data among a pack of rats, so that if one rat were out of direct contact with its operator, its signal could be picked up and relayed by other rats.
There are also ethical concerns. Animal rights activists feel the process is demeaning to animals. Others worry about the same process being applied to people. The scientists who conducted the experiments reject human experiments, but they insist the rats were treated very well and seemed to enjoy what they were doing.
The biggest problem may simply be the fact that you’re dealing with rats. They could easily be distracted by blood or other remains in rubble, and neither rescuers nor victims are likely to enjoy the sight of rats scurrying around. But over time, says Dr. John K. Chapin of the State University of New York, one of the researchers, people might actually learn to like rats. “Maybe if it becomes widely known there are these rescue rats,” he suggests, “people wouldn’t be scared.”
I guess we’ll just have to wait and see…preferably not alone in the dark.
