Photograph by Rebecca Hale, National Geographic
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National Geographic Explorer Steve Ramirez has manipulated the brain cells of mice to create a "memory" of something that never happened.

Photograph by Rebecca Hale, National Geographic

This Scientist Wants to Steal—and Implant—Memories

MIT's Steve Ramirez aims to wipe out bad memories and has even implanted false memories in mice. 

Steve Ramirez tinkers with memories. He has given mice amnesia, and aims to implant false memories—all in the interest of learning how to help people remember and forget.

The National Geographic Channel will examine these and other mysteries of the brain in Breakthrough: Decoding the Brain, airing Sunday at 9 p.m. ET. The episode is directed by Brett Ratner, director of Money Talks, Rush Hour, and Red Dragon, the Silence of the Lambs prequel.

Ramirez, a National Geographic Emerging Explorer as well as a recent MIT PhD who is about to start his own laboratory at Harvard, wants to learn how to “dial up the emotional oomph” of good events and dial down the bad ones to eventually help patients with PTSD and depression.

What fascinates you about the work you do?

Tucked in between your ears, you have the one thing that we theoretically could never have: a time machine. You close your eyes, you can think back to your memory of your first kiss, the time you got to college, your last break-up. And you don’t break a sweat. I’m enamored of the idea of reverse engineering this mental time machine.

The technology you’re using is called optogenetics. What is that?

Optogenetics is this idea of going into the mouse brain and finding individual brain cells that hold on to particular memories. You can find a handful of brain cells that hold on to one memory, and we can genetically engineer just those cells to respond to light—so that now when we go in and shoot light into the brain, it reactivates that set of brain cells holding on to one memory and that reactivates the process of recollection.

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And you see optogenetics as a potential treatment for diseases like PTSD and depression?

Imagine we could dial up the emotional oomph associated with a positive memory or dial down the emotional oomph associated with a traumatic memory. Ideally, you can rewrite the contents of the memory in a more therapeutic manner.

This is all still just in mice, though. Will it ever be possible in people?

In terms of scaling up from mice and men, it’s a matter of when and how, not a matter of if this will happen. We’re technologically not even close, but there’s no law of physics that says it’s not going to happen—we just need better tools.

Obviously, there’s concern about people misusing these tools to implant memories or remove ones for nefarious reasons. What can be done about that?

What we can do is start the dialog now, 40-50 years before it’s even possible, so nobody is caught off guard. One way of circumventing those ethical issues is to strictly use it in a clinically relevant setting–you give it to the patient who’s afflicted with depression or the war veteran with PTSD.

So, if the big payoff for your research is decades away, are there things that it can help us with in the meantime?

When you’re looking at mice and rats, you’re looking into an evolutionary mirror, into how the stuff that makes you tick works. What we’re getting is a pretty good map of how memories are realized in the brain, how they change over time, how reliable or unreliable they are, what happens when we manipulate them in various contexts. We need to know how to control the fire that we’re playing with. That’s something that the animal research really grants us.

How do you find the brain cells that are holding on to specific memories?

Whenever a brain cell is active, there is a corresponding set of genes that turn on in that cell. We can go in and ask which brain cells have these genes turned on. Those were recently involved in storing a memory.

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Neuroscientist Steve Ramirez uses light to activate memories in the brain.

Is there some new insight or upcoming research that you find particularly compelling?

A separate team that works in our lab using similar technology is able to successfully bring back a memory in animal models of Alzheimer’s. There’s this ongoing debate: If your brain is a library and the books are memories, does Alzheimer’s eat away at the librarian so you no longer have access to those memories, or does it eat away at the books themselves? What it seems to be is it’s actually possible to go in and artificially restore memories that were thought to be gone.

If you could change any one of your own memories, what would it be?

The 2007 New England Patriots. If I could have erased the memory of them losing the Super Bowl or could make it a false memory, I would do that in a heartbeat.

This interview has been edited and condensed. Follow Karen Weintraub on Twitter.