June 18, 2011
Scientists Spark Lost Memories In Rats
U.S. scientists have developed an on-off memory switch that helped laboratory rats remember a behavior they had forgotten.
The brain prosthesis marks the first time scientists have been able to duplicate the brain's learning process, restoring memories that test rats were drugged to forget.
This new research could help offer hope for people suffering from dementia.
"Flip the switch on, and the rats remember. Flip it off, and the rats forget," Theodore Berger of the University of Southern California's Viterbi School of Engineering's Department of Biomedical Engineering said in a statement.
The researchers focused on the hippocampus, the section of the brain where memories are made, during their research.
The communication between two regions of the hippocampus results in a short-term memory being converted into a long-term memory.
The researchers studied the signals being sent to these subregions as rats learned a task that involved pressing a lever in order to get a reward.
Once scientists drugged the rats to halt neuron signals between the two regions, the rats forgot the long-term memory.
However, when they implanted an electronic brain prosthetic that duplicated the signaling process between the subregions, the rats were able to start remembering.
The study said in normal rats, "the device could actually strengthen the memory being generated internally in the brain and enhance the memory capability."
The team hopes to test the device in monkeys next.
The study was published in the Journal of Neural Engineering.
Image 2: In the experiment, the researchers had rats learn a task, pressing one lever rather than another to receive a reward. Using embedded electrical probes, the experimental research team recorded changes in the rat's brain activity between the two major internal divisions of the hippocampus, known as subregions CA3 and CA1. The experimenters then blocked the normal neural interactions between the two areas using pharmacological agents. The previously trained rats then no long displayed the long-term learned behavior. But long-term memory capability returned to the pharmacologically blocked rats when the team activated the electronic device programmed to duplicate the memory-encoding function. Credit: USC Viterbi School of Engineering
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