I was intrigued by the 2004 film Eternal Sunshine of the Spotless Mind which is a film about a couple who, after a bad breakup, have literally erased each other from their memories. (It was written by Charlie Kaufman, directed by Michel Gondry and stars Jim Carrey, Kate Winslet, Kirsten Dunst, Mark Ruffalo, Elijah Wood and Tom Wilkinson.)
The film is a mix of science fiction and romantic comedy and explores memory through romantic love. The premise is that a company called Lacuna has developed a way to find and erase specific memories in the brain. You can have that terrible memory removed. It was science fiction, but last year, MIT researchers have shown, for the first time ever, that memories are stored in specific brain cells. That means that if you removed those cells, you would remove the memory.
They could trigger a small cluster of neurons and force the subject to recall a specific memory, and then by removing these neurons, the subject would lose that memory.
Don’t go looking for a way to contact Lacuna just yet. The researchers had to do some fancy genetic manipulation of cells so that they’re sensitive to light, and trigger them using lasers by drilling a hole through the subject’s skull.
MIT’s subjects were mice.
But it is believed that the human brain functions in the same way. Breeding humans with optogenetic brains is not part of their immediate plans though.
Following up on that research, the findings get weirder. It seems that our “memory neurons” (nerve cells of the hippocampus) play a crucial role in storing and retrieving memories.
I can’t explain the molecular basis for memory formation — an enzyme from the topoisomerase family responds to new stimuli by breaking DNA, which seems to activate genes are inhibited by a system of enzymes and…
And we still don’t have all the answers. Researchers at Stanford have a theory about mobile memories. They believe that the hippocampus does store the specifics of new memories, but those memories move to elsewhere in the brain after a time. The team found that if they disrupted the hippocampus within a month or so of a new memory, the memory disappeared forever. If they disrupted it after a longer period of time, the memory seemed undisturbed — as though it no longer physically resides in those same cells.
I still like the idea that everything you have ever experienced and remembered is stored in that beautiful hard drive of a brain. We get a lot of “file not found” error messages, but the files are all there. Some of those memory files get corrupted over time, but one day there will be a really good defragging programs – even better than sleep and a vacation – that will fix all those bad sectors and restore all the memories and connections.