UCLA Research Suggests Erasing Traumatic Memories May Be Possible In The Future

Posted by: Andrew Kolbenschlag on May 9, 2011 at 12:50PM
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Erasing Memories—Science Fact?

In the 2004 film “Eternal Sunshine of the Spotless Mind,” Joel Barrish, played by Jim Carrey, finds himself in a seemingly hopeless situation: his relationship with his girlfriend has fallen apart, and Joel, unrequited and hopeless, can not imagine living with the pain of a love lost.

To make a long story short (and relevant), Joel opts to undergo a revolutionary medical procedure—his memories of his ex are erased, and he forgets that the relationship ever happened at all.

Fiction, right? Well, for now, yes, but according to David Glanzman, a neuroscientist at the University of California (Los Angeles), the ability to erase traumatic memories might not be confined to Hollywood.

Glanzman and his team of researchers—Diancai Cai, Kaycey Pearce, and Shanping Chen—have successfully erased the long-term memories of a marine snail, Aplysia (commonly called the California Sea Hare). The results of the team's study appear in the April 27th issue of the Journal of Neuroscience. Rather than easing the minds of forlorn lovers, however, Glanzman’s work could have real-life, meaningful applications—such as healing those with post-traumatic stress disorder or better understanding Alzheimer’s disease.

Aplysia

To most of us, memory alteration in a marine snail might not seem like a precursor to advanced medical procedures in the human brain, but Aplasyia has gained a reputation as the go-to test subject in much modern neurological research. Glanzman claims the snail makes a very satisfying human analog in terms of the structures of memory.

"Almost all the processes that are involved in memory in the snail,” he said, “also have been shown to be involved in memory in the brains of mammals.” And so while the human brain is far too complicated and complex for this type of research, what scientists are learning from Aplysia can be applied to the human brain, and will serve as the foundation for future research. "The fundamental mechanisms of learning and memory are identical,” in the human brain, said Glanzman.

Glanzman’s research focused on a specific enzyme—protein kinase m, or PKM—in the snail’s brain. To put it simply, PKM is thought to reinforce synaptic connections between neurons in the brain, turning busy synapses into permanent connections, and thereby transforming short-term memory into long-term memory. This process is not completely understood; one of the goals of the study was to better understand the role of PKM in maintaining memories. The team found that by removing PKM from the equation, they effectively erased long-term memories.

Making Snails Forget

To carry out the experiment, researchers administered electric shocks to the snails. Afterwards, the scientists touched each snail’s siphon enough so that the snail would react by contracting.

This is a simple form of learning—the scientists shocked the snail first, teaching it that being touched is not a desirable event, and then touched it again later, hoping to trigger the memory of the shock. Glanzman called this process a "fundamental form of learning that is necessary for survival and is very robust in the marine snail.” Control snails, when touched, having never been shocked, contracted for just a few seconds. The snails that had previously been shocked, though, contracted for about 50 seconds.

Even about a week after the initial shocks, the snails would respond to stimuli in the same way, contracting for more than 30 seconds, ten times that of the control. This, according to Glanzman, demonstrates the snails’ long-term memory.

Once the long-term memory was established, the snails were injected with a PKM inhibitor. 24 hours later, the learned behavior was gone, and the snails reacted to touch exactly like the control snails—as if they had never been shocked. Once the PKM inhibitor is injected, says Glanzman, "The long-term memory is gone.”
In addition, the team established a neuronal synaptic circuit in a Petri dish using Aplaysia neurons. The PKM inhibitor erased the long-term memory in these cells as well, corroborating the results of the shock test.

What is the Future of Memory Alteration?

It is important to remember that this research is being done on snails, and practical applications of memory alteration in humans may not be possible in the near future. But, it is possible. "Not in the immediate future,” says Glanzman, “but I think (someday) we will be able to go into one's brain, identify the location of the memory of a traumatic experience and try to dampen it down. We can do this in culture, and there is no essential difference between the synapse in culture and the synapse in your brain. We have captured the memory in the dish; now we have to figure out a way to target the memories in human brains. Once we know the neural circuit that contains the memory, then we need a selective way to inhibit the activity of PKM in that circuit." Then, and only then, says Glanzman, “we may be able to alter long-term memories.”

The implications of such capabilities could mean new treatments for a variety of sufferers. If memories could be targeted, then perhaps symptoms of post-traumatic stress disorder could be lessened or eliminated, which could mean a much higher standard of living for survivors of severely traumatic events. A better understanding of the relationship between PKM and memory could also lead to advances in the treatment of addiction and even Alzheimer's disease.

Blessed Are The Forgetful?

Although a Hollywood-style memory adjustment is a long way off, there is an important takeaway here: they are working on it. Whether you welcome such research or not, it is advancing, and that means someday, it will no longer be a question for the future.

So, why not start the public discussion now? If traumatic memories could be altered or erased, how should we go about it? How should we decide who is eligible? From veterans of wars to victims of child abuse to survivors of rape, many people could benefit from easing traumatic memories. Undoubtedly, nothing as trivial as a breakup would warrant a procedure of this magnitude, but a line would have to be drawn somewhere.

Perhaps more importantly, we must consider the philosophical implications of this type of pursuit. As human beings, we are shaped by our experiences. In a very real way, you are the aggregate of your experiential memories. What would be the effect of changing even one of those memories? Even in situations where memories are insurmountable and life for sufferers is almost impossible, is there virtue in forgetting? Is it better to suffer with the truth or to lead a happy life without it?

There are a lot of serious questions here, and this article is not intended to conjure up fear or panic, but rather initiate a conversation. What do you think?