Memories can be restored in drugged rats literally with the flick of a switch and the same can possibly be done to human beings suffering from dementia, according to researchers at Wake Forest University and the University of Southern California (USC).

In the experiment, rats were trained for a long time to learn a task - push a specific lever to get a reward, in this case, water. Thereafter, the rats were drugged with pharmacological agents and fitted with tiny electrodes.

When the electronic system is switched off, the drug makes the rats forget the connection between pushing a lever and getting water, a long-term learned behavior.

However, with the flick of a switch, the tiny electrodes, which duplicated the neural signals associated with memory, helped the rats remember the connection between the lever and the reward.

Turning on the electronic switch helped recovery of the memory while turning off the switch made the rats lose their memory.

Flip the switch on, and the rats remember. Flip it off, and the rats forget, said Theodore W. Berger, a professor of engineering at U.S.C. and the lead author of the study, which is being published in The Journal of Neural Engineering. His co-authors were Robert E. Hampson and Anushka Goonawardena, along with Dr. Sam A. Deadwyler, of Wake Forest University, and Dong Song and Vasilis Z. Marmarelis of USC.

According to Berger, the experiment revealed that long-term memory capability, that was blocked by drugs, could be recovered when the team activated the electronic device programmed to duplicate the memory-encoding function.

In addition, the researchers went on to show that if a prosthetic device and its associated electrodes were implanted in animals with a normal, functioning hippocampus (part of the brain area that is crucial for forming new memories), the device could actually strengthen the memory being generated internally in the brain and enhance the memory capability of normal rats.

These integrated experimental modeling studies show for the first time that with sufficient information about the neural coding of memories, a neural prosthesis capable of real-time identification and manipulation of the encoding process can restore and even enhance cognitive mnemonic processes, the research paper entitled A Cortical Neural Prosthesis for Restoring and Enhancing Memory said.

The researchers said they want to duplicate the same results in primates (monkeys) and are hoping that this discovery will one day help human victims of strokes, Alzheimer's Disease, or any other injury-induced dementia.