Picture a world where traumatic memories can simply be erased. That’s what doctors are trying to achieve at Harvard Medical School and McLean Hospital in Boston. Their most recent study demonstrated that application of xenon gas has the ability to block or reduce the memory of painful events in laboratory animals. In announcing their findings, lead researcher Dr. Edward G. Meloni, a psychologist at McLean Hospital, said, “It’s an exciting breakthrough, as this has the potential to be a new treatment for individuals suffering from PTSD.”
The team conditioned mice to associate certain events with painful shocks. After the mice were treated to a burst of xenon gas, their fear response associated with those events went away for up to two weeks. Xenon has the ability to interrupt the memory formation process, but it was unclear from the experiment whether this could dissipate older memories, or just prevent the formation of new ones. A great benefit of using xenon gas is that it is already being used for medical purposes such as imaging and anesthesia.
The Noble Gas
Xenon is a noble gas, which means that its atomic structure is stable and doesn’t react with other substances very easily, making it easier to deploy with greater precision. Meloni explained, “Xenon gets in and out of the brain very quickly. This suggests that xenon could be given at the exact time the memory is reactivated, and for a limited amount of time, which may be key features for any potential therapy used in humans.”
Similarly, helping those who suffer from PTSD is a noble goal. The National Institute of Health reports that at least 7.7 million people are diagnosed with this disorder, including one third of all veterans. It seems at first like a perfect arrangement of a precision treatment option for an expanding medical challenge.
Never Forget
A year ago, MIT Technology Review permitted Bioethics professor Arthur Caplan to consider the hidden dangers of targeted medical forgetting stemming from research by Daniela Schiller at Mount Sinai School of Medicine in New York. Her work on addiction, phobias and profound anxiety disorders let her to experiment on deleting traumatic memories using pharmaceuticals coupled with electroshock.
Caplan points out that at the cultural level, the motto “Never Forget” has been applied to many atrocities, from the Holocaust to 9/11, suggesting that forgetting is the first step to allowing history to repeat itself. There are obvious parallels at a personal level. Beyond that, losing our most unpleasant memories rob us of the ability to feel sympathy or empathy. Finally, citing “neuralyzers” from the movie Men in Black, Caplan suggested that if this technology becomes practical, there are many organizations, governments and private firms that might easily take it under their own authority to determine what kinds of memories need to be deleted.
Human Trials
Meloni plans to begin human trials within the year and quickly move on to PTSD patients. The larger question may become how doctors will be able to help patients cope with ingrained visceral responses to events that they no longer remember.