The conventional wisdom regarding memory-loss diseases such as amnesia and Alzheimer’s has long been that all affected memories are erased or destroyed.
But a new study from MIT is suggesting a possible alternative: that while the ability to access memories may vanish, the memories themselves may still be fully intact and encoded within the brain.
“If you ask a neuroscientist what we know about memory, most people will say we have these pathways, or traces, that are formed in the brain, and these are somehow required for us to recall information accurately,” MIT researcher and study co-author Dheeray Roy told Yahoo Canada.
“In cases of amnesia, a lot of people would believe these traces actually are non-existent, and that’s the underlying cause of the disease. Our study came in, I think, to ask whether amnesia truly is a storage-type issue, or whether some memories do persist and there is just no way to access them – and can we do something about it?”
A technology called optogenetics is enabling researchers to implant memories in rodents, create amnesia, and revive the memory using precisely-focused microbeams of light, Roy said.
“In our study, we tagged or engineered these memory engram cells, which we believe participate, or are necessary for, the formation and retrieval of a stable memory,” Roy explained.
A mouse or rat with amnesia is placed in a setting where it suffered a frightening experience it can no longer remember. With the activation of the light, the memory returns.
“Animals, like humans, have a very robust response when they don’t like something,” Roy said.
“They quickly display avoidance behavior. This becomes a way of testing specific memories.”
And it’s not a fluke, either.
“It’s amazing how robust the response is, and how long it lasts – up to one year,” Roy said.
The findings are very new. Roy freely concedes it will take more than this for many in the field to accept and embrace the findings. And while the MIT research clearly singled out amnesia, any breakthrough in memory science will always raise hopes of a possible imminent treatment or cure for the ever-increasing global epidemic of Alzheimer’s disease.