Washington, July 17 (IANS): A team of researchers has developed a tiny wireless device that, once implanted in the brain, can be activated by remote control to deliver targeted drugs.

The device, the size of the width of a human hair, may be used to treat pain, depression, epilepsy and other neurological disorders in people by targeting therapies to specific brain areas.

"In the future, it should be possible to manufacture therapeutic drugs that could be activated with light," said co-principal investigator Michael R Bruchas, associate professor at the Washington University's school of medicine in St. Louis.

With one of these tiny devices implanted, doctors could theoretically deliver a drug to a specific brain region and activate that drug with light as needed.

"This approach potentially could deliver therapies that are much more targeted but have fewer side effects," Bruchas added in a paper published in the journal Cell.

The technology was successfully demonstrated for the first time in mice.

The researchers showed that by delivering a drug to one side of an animal's brain, they could stimulate neurons involved in movement which caused the mouse to move in a circle.

In other mice, shining a light directly onto brain cells expressing a light-sensitive protein prompted the release of dopamine, a neurotransmitter that rewarded the mice by making them feel good.

The mice then returned to the same location in a maze to seek another reward.

But the researchers were able to interfere with that light-activated pursuit by remotely controlling the release of a drug that blocks the action of dopamine on its receptors.

The new device is built with four chambers to carry drugs directly into the brain.

By activating brain cells with drugs and with light, the scientists are getting an unprecedented look at the inner workings of the brain.

"This is the kind of revolutionary tool development that neuroscientists need to map out brain circuit activity," noted James Gnadt, program director at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health (NIH).

The researchers also believe that similar, more flexible devices could have applications in areas of the body other than the brain, including peripheral organs.