Massachusetts Institute of Technology researcher Li-Huei Tsai published a study Thursday in the journal Cell about an experimental drug that erases traumatic memories in mice.
Tsai and her researchers concluded that one dose of the drug, called a histone deacetylase 2 inhibitor, allowed the mice to forget memories from the distant past that had caused fear or anxiety.
“We are interested in the mechanism in underlying memory extinction, especially at the cellular-micro level,” Tsai said. “There is this very well established observation in the literature that recent memory can be extinguished using behavioral training. But distant memory or long-term remote, or old memories, are more resistant to extinction training.”
Because anxiety disorders are not scientifically curable, there are very few strategies used to erase traumatic memories in humans. However, Tsai said her study shows how behavioral training, mixed with a dose of HDAC2, could be the key to erasing these memories.
According to Tsai’s research, the HDAC2 inhibitors make the brain more malleable and allow patients to learn new associations and replace the traumatic memory.
“Based on our previous studies, when we look at the memory reconsolidation process, to our surprise, increase in histone isolation seems to play a very important role in reconsolidation and extinction,” she said.
Postdoctoral associate Damien Rei worked with Tsai on the research project, said this research has a lot of translational value.
“That data has been acquired, and there are a lot of interesting possibilities for the patients and patients in particular that are suffering from PTSD,” he said.
Rei said there are multiple possibilities for using the study’s results, though more research still needs to be done. Researchers would most likely test the HDAC2 inhibitors on monkeys before introducing it to people.
“If investigators think that the drug used in the study is good enough, the next step is to do clinical trials,” he said. “So, in that regard, it could take five or 10 years before actually getting the drug on the market.”
Tsai said she hopes scientists who focus on post-traumatic stress disorder, anxiety problems and addiction will further study the results of her research and that future research will address some of the issues that were discovered in the most recent study.
“In terms of the more translational aspect, small molecule HDAC inhibitors were developed previously for oncology purposes,” she said. “For the central nervous system, there is always this concern about safety. Now I understand there are pharmaceutical companies that have HDAC inhibitor programs with the goal to identify more content and safe compounds that can be administered to humans.”
Several residents said they were wary of a drug that can permanently affect memories. Percy Ballard, 32, of Fenway, is skeptical of any drug that can erase memories permanently. He said he would only recommend it to someone who has a full understanding of the risks and benefits of taking it.
“The brain isn’t like a hard drive,” he said. “You can’t just erase it. If the memory is suppressed, there would probably be something left behind, like some sort of a symptom.”
Joe Holt, 20, of Back Bay, said the drug could be useful for people returning home from conflicts overseas.
“For people coming back from wars that want to forget that part of their lives, that could be kind of cool,” he said. “If I knew someone who went through something so bad they needed it, I guess I would recommend it to them.”
Zachary Kerr, 20, of Fenway, said he thought any drug that inhibits the brain and its natural functions is not good.
“I wouldn’t recommend a drug like that because I feel like anything like that needs to be dealt with physically,” he said. “[They should] go to a therapist or talking to someone about it. I think that just chemically suppressing memories isn’t good.”