Switch turns memories on and off

AN ON-OFF memory switch that helped laboratory rats remember a behaviour they had forgotten has been developed by US scientists.

The brain prosthesis marks the first time that researchers have been able to duplicate the brain's learning process, restoring memories that test rats were drugged to forget, and could offer hope for people with 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 department of biomedical engineering, said on Friday.

Advertisement: Story continues below
Working with the physiology and pharmacology at Wake Forest University, North Carolina, Professor Berger's team focused on the hippocampus, the section of the brain where memories are made. The communication between two regions of the hippocampus results in a short-term memory being converted into a long-term memory.

The team studied the signals sent between these sub-regions as rats learnt a task that became a long-term memory. When scientists drugged the rats to halt signals between the regions, the rats forgot the task. When they implanted an electronic brain prosthetic that duplicated the signalling process, the rats remembered.

In normal rats, ''the device could actually strengthen the memory'', said the study, published in the Journal of Neural Engineering.