Memory is not erased, is revivable.
By Raif Karerat
WASHINGTON, DC: New research conducted by researchers has demonstrated that science could be capable of retrieving lost memories from the recesses of amnesiac patients’ brains, according to a study published Thursday in the journal titled Science by the Massachusetts Institute of Technology and Riken Brain Science Institute in Japan.
Researchers in the lab of Susumu Tonegawa and at the Picower Institute for Learning and Memory at MIT conducted a series of studies using light-based brain tracking techniques on mice to show that memories in certain forms of amnesia aren’t erased, but remain intact and potentially revivable, reported Time.
According to the Washington Post, scientists instituted a method called optogenetics in order to reinvigorate memories in the mice:
Scientists can pick out specific neurons and introduce a special protein to them by way of an engineered virus. Once that protein is present in the brain cells, the cells are sensitive to blue light. That allows researchers to turn particular neurons on and off at will.
In this case, they created a bad memory by shocking mice repeatedly in a particular enclosure. They picked out which neurons were stimulated when the mice relived the memory (as evidenced by their visible fear of being in the shock chamber) and made those neurons, which together are called a “memory engram,” light-sensitive in a new batch of mice before training them with the same shock.
They then made the memories go away using a drug that inhibits memory formation, which duly removed their fear of the shock chamber until researchers used a blue light to trigger the neurons that influenced the reaction to the shock chamber.
“We have strong reason now to believe that memory storage — that is, the storage of the memory information itself — is encoded through connectivity patterns of engram cells throughout the brain,” Tomas Ryan, a neuroscientist at MIT and a co-author of the study, explained to The Verge.
However, he cautioned optogenetics are difficult to implement with human subjects, party for ethical reasons due to its invasive nature and also because the scientists need to tag the memories in the brain before they’re learned, meaning “if the researchers wanted to help someone recover a memory, they would have to be present when the memory was formed.
Nevertheless, the findings open up a whole new realm of possibilities to explore which could lead to advances in amnesia and Alzheimer’s in the future.
“Our conclusion is that in retrograde amnesia, past memories may not be erased, but could simply be lost and inaccessible for recall,” lead author Susumu Tonegawa, director of the RIKEN Brain Science Institute in Saitama, Japan, said in a statement. “These findings provide striking insight into the fleeting nature of memories, and will stimulate future research on the biology of memory and its clinical restoration.”