An electronic implant designed to mimic the function of a brain area damaged by Alzheimer’s disease could help patients regain memory.
The inability to remember new things is one of the earliest signs of the neuro-degenerative disease that is believed to be behind up to 70 per cent of dementia cases.
The technology being developed by a team of scientists from Wake Forest Baptist University, USA, could potentially provide a solution in future by replicating the function of the hippocampus - the area responsible for consolidation of information from short-term to long-term memory - which is also one of the first regions of the brain damaged by the disease.
In tests that have so far only been conducted on animal models, the researchers used a small array of electrodes to translate neural memory signals into a form suitable for long-term memory storage - something that naturally occurs in the hippocampus.
"Although this sounds like the stuff of science fiction stories, the researchers are addressing a major problem for people with Alzheimer's disease and other forms of dementia - the ability to lay down new memories,” Clare Walton, research manager at Alzheimer's Society commented on the technology, which was presented at the Annual International Conference of the IEEE Engineering in Medicine and Biology Society in Milan, Italy.
“The practical upshot of this is that people may have clear memories of events from their childhood, but can't remember the details of what took place yesterday,” she said.
Nine human subjects have had the implant fitted, all epilepsy sufferers that had electrodes implanted into their brains previously.
The researchers ran a series of computer simulations, which suggested the translation of the neural signal was accurate in 90 per cent of the cases.
"Being able to predict neural signals with the model suggests that it can be used to design a device to support or replace the function of a damaged part of the brain," said Professor Robert Hampson from Wake Forest Baptist University.
The team plans to undertake a new series of experiments that would attempt to transmit the translated signals back to the patients' brains to see whether they could trigger the formation of long-term memory.
“In theory this device has the potential to help people to form new memories even when their hippocampus is damaged,” said Walton.
However, she warned it will take years to see the first practical implementations.
"There are still many unknowns that need to be worked out by the scientists. It's encouraging to see these cutting-edge technologies being applied to help people affected by memory loss, but this isn't something that people with dementia can expect to be readily available in the next decade."
Creating memories and storing them in the long term is a complex process that requires the brain to first receive a sensory signal, which is translated into an electrical signal that subsequently travels through various parts of the hippocampus. After multiple re-encodings, the signal is sent for long-term storage.
Any damage that prevents this translation process means that a long-term memory cannot be formed. Alzheimer’s disease sufferers therefore struggle to remember recent events although they can still clearly recall memories from the more distant past.