Memory is kindve a given – right? We trust what we remember actually happened. That’s probably why Hollywood likes to make so many science fiction ilms about our memory – Inception, Eternal Sunshine of the Spotless mind, Total Recall, etc.. – because it can scare us a bit to think that something so basic and essential and reliable could be corrupted. But recently two scientists may have discovered a way to make those science fiction films less fiction, and more science.
The story starts at MIT, where nueroscientist Xu Liu and doctoral-student Steve Ramirez were working with mice in their lab. What they had discovered was that when they put a mouse into a box, shocked the mouse, removed the mouse and then put it back into that same box later, the mouse froze, recalling the memory of being shocked before and freezing as a defense mechanism. This meant that the mouse remembered the box and what had happened in it. That wasn’t groundbreaking science, but what happened next was. In order to understand what Liu and Ramirez did, one first needs to understand something called optogenetics. Optogenetics is the process of modifying neurons in the brain to be activated by light. Steve Ramirez told psych report, “The nifty part about optogenetics is that brain cells don’t normally respond to light, so in this case, the only ones that respond to light are the ones that you trick to respond to light,”. When the scientists changed the cells of the brain to be light activated, it allowed them to track the storage of memory in the mouse’s brain and use light as an on and off switch to activate or deactivate the memory.
Their experiment was this: they put a new mouse into a box and let the mouse sniff around, but they didn’t shock it. They just let the mouse form a memory of the box, let’s assume it was a blue box, and then they tracked those memories. Then they put the mouse into a red box, and while the mouse was in the red box they shocked it. While the mouse was in the red box and was being shocked, they used optogenetics to reactivate the mouses memory of the blue box. Just to reiterate: mouse is in the red box being shocked while his memories of the blue box are being reactivated. Then they put the mouse back into the blue box, and it froze, prompting Ramirez to email Liu, who wasn’t present at the time, an email with the subject line “Merry Freaking Christmas!” This was a breakthrough for the two scientists, a culminating climatic moment after more than two years of research. What this meant was that the scientists had falsely implanted a memory into the mouses brain – they had convinced the mouse that it had been shocked in the blue box, when in fact that was not true. They had artificially manufactured a memory.
This is very much an open field. There is no precedent or anything like it done before, so really it can go anywhere. The hope is to use it to someday cure conditions like Alzheimer’s and PTSD. Of course the technology is years away from being able to be used safely in humans, but it’s an incredible start.