Researchers at MIT have theorized that lost memories may be retrieved using light therapy to activate brain cells. The idea is discussed in an article in the journal, Science, using a technology called optogenetics.
Memories lost as a result of amnesia and other conditions were thought to be permanent based on the areas of the brain storing those memories being in such bad shape that the thought centers of the brain could no longer access them. However, light therapy directed at specific brain cells or neurons may be able to bring those memories back.
Dr. Susumu Tonegawa, director of the research into optogenetics at MIT, said, “The majority of researchers have favored the storage theory, but we have shown in this paper that this majority theory is probably wrong,” adding, “Amnesia is a problem of retrieval impairment.”
Essentially, optogenetics involves adding proteins to neurons that allow them to be activated with light. In 2012, MIT researchers used optogenetics to prove that a population of neurons exists in the part of the brain known as the hippocampus. This latest research has now proved that these neurons undergo chemical changes, otherwise known as memory consolidation.
“We were able to demonstrate for the first time that these specific cells,” Tonegawa explained, “had undergone this augmentation of synaptic strength.” Researchers working under Tonegawa have showed that memories are not stored in synapses, but rather a circuit of multiple groups of engram cells that encompasses several areas of the brain.
The bottom line of the research is that a retrieval glitch is responsible for memory loss, and so retrieving those memories is all about fixing the glitch. Optogenetics offers hope that one day memories that have been lost may be found and restored.