Remember Last Night?

Remember that time in first grade when you were sitting on the bus home from summer camp, and suddenly you started to feel something a little wet and suspicious in between your legs? And then, two seconds later, you realize there is a very distinct smell to accompany that uncomfortable feeling? Before you knew it, the whole bus is pointing and laughing at you and the puddle of pee you’re currently sitting in. It’s happened to all of us…right?

But fear no more! Thanks to that thing called science, a pill to “erase” painful memories could be on its way in the very near future. Hold up. Let’s recap what I just said: a pill that erases bad memories. But how can something like that possibly exist? It sounds more like a potion from one of the Harry Potter books than a medication. Well, as it turns out, science and magic may not be to separate from one another, because neuroscientists have already made many significant steps toward the development of such a pill. But, before we talk about memory erasure, it is first necessary to give a brief overview of how memories are stored and recalled.

Memory storage in the human brain is the result of a process known as long-term potentiation, which is essentially a strengthening of the neural networks that encode for that memory. A wise man named Donald Hebb once said “neurons that fire together, wire together,” and there is no better example of this phenomenon than in long-term­ potentiation. For example, let’s say that every time I said hello to my friend Max, he punched me in the face. If I said hello to him enough times, the connection between the neurons in my brain that fire when I say hello to Max and the neurons in my brain that fire in response to getting punched in the face by Max would grow strong enough that, eventually, I would learn to stop saying hello to that dick. Many molecular factors are acting to strengthen these neural connections, including, but not limited to, increased neurotransmitter release, increased conductance of calcium (calcium aids in the release of neurotransmitter), and even growth of dendritic spines (these receive neurotransmitters).

Once memories are formed, they stay in the brain forever, stagnant and unchanged, like an engraving in a tablet, right? Wrong. Recent studies seem to suggest that every time a memory is recalled, new proteins are put in motion to alter and change the original memory. It appears that every time a memory is recalled, it changes slightly. It is this fact that would enable a memory erasure pill to work its magic.

In a study conducted by Karim Nader and Joseph LeDoux at NYU, rats were trained to associate a loud noise with an electrical shock, and thus exhibited behavioral characteristics associated with fear whenever the noise was sounded. After an injection of a chemical known to block certain proteins involved in memory synthesis and recall, however, the rats failed to exhibit fear upon hearing the noise. More astounding, after the chemical had worn off, the rats still showed no fear of the noise. When put in a situation where memory recall was necessary, but with no access to the proteins involved in memory recall, the memory, essentially, vanished.

Neuroscientists already have a jump on one protein, PKMzeta, that seems to be heavily involved in memory consolidation and recall. The implications of this pill for treatment of syndromes like PTSD are ridiculous, and I’m sure the ethical debate surrounding its production will be long and controversial. Right now, however, the concept is pretty cool.