A debilitating fear, a tragic loss, or a bad habit: it seems like we all have something we would like to forget.

For many people, painful memories can affect every part of their lives. Now researchers are studying ways to help them forget.

Pictures, medals and pins are reminders of a time war veteran Allen Megginson would rather forget.

"I think that no matter how much time passes, it's really not going to ease the pain any," says Allen.

Allen fought in the Iraq War. What he saw and experienced are now memories that haunt him every day.

"Sometimes the wounds that hurt the most are the ones you can't see," he says.

But what if Allen could forget those horrible memories?

After decades of research, Dr. Andre Fenton and colleagues have discovered what they call the memory molecule.

"This is the first physical identification of a molecule that is definitively important for storing memory," says Dr. Fenton, neuroscientist and associate professor of the department of physiology and pharmacology at the SUNY Downstate Medical Center in Brooklyn, NY.

In a lab experiment, Fenton manipulated that molecule in the brains of rats. The animals were put on a turntable. One area delivered a mild shock to the foot.

But when researchers injected a drug called ZIP into their brains, the rats went straight to the spot that shocked them. They forgot what they had learned.

"We could always see that the animals could no longer remember to avoid that particular place," says Dr. Fenton.

While this research is in animals, investigators from Harvard are studying whether another drug -- propranolol -- can weaken the emotional response to memories in humans.

But medical ethicist Felicia Cohn says there are real concerns about editing memory.

"You start changing somebody's memories, you can raise the question of whether or not you're changing their identity in some fundamental way," says Dr. Cohn, director of medical ethics at the University of California, Irvine.

Even Allen says he would not want to take a drug to help him forget.

"I may have these bad memories, but they make me the person I am today," says Allen.

Researchers are also studying the effects of certain painkillers, anti-nausea drugs and the abortion drug RU486 for memory blocking in animals.

RESEARCH SUMMARY
ERASING MEMORIES
REPORT #1616

BACKGROUND: According to the National Institute of Mental Health, posttraumatic stress disorder, or PTSD, is an anxiety disorder that some people get after seeing or living through a dangerous event. The intense fear triggers split- second changes in the body to defend against danger. In PTSD, this reaction is changed or damaged. People with PTSD may feel stressed or frightened even when they are no longer in danger. Anyone can develop PTSD at any age. War veterans and survivors of physical and sexual abuse are commonly diagnosed with the disorder. Not everyone with PTSD has been through a dangerous event. Some people develop PTSD after a friend or family member experiences danger or is harmed. The sudden, unexpected death of a loved one can also cause PTSD.

ERASING MEMORIES: It sounds like science fiction, but some researchers are studying whether certain drugs can erase or dim bad memories. The possibility of memory blocking has some ethicists concerned. Felicia Cohn, Ph.D., director of medical ethics at the University of California, Irvine, says erasing memories may be erasing someone's identity. "If you start changing somebody's memories, you can raise the question of whether or not you're changing their identity in some fundamental way," Cohn told Ivanhoe. She says even bad memories teach us important lessons. "Whether it means we become more protective with our children or we lock our doors more often at night, or you know, even subtle behavior changes can really make a big difference in the way we live," Cohn said.

ZIP: Researchers in Brooklyn are studying the drug known as "ZIP" in animals. They conducted an experiment where they put the animals on a turntable. One region of the table delivered a mild foot shock, so the animals learned to stay away from that area. After the researchers injected ZIP into their brains, the rats went straight to the spot that shocked them, meaning they forgot what they had learned.

PROPRANOLOL: Researchers from Harvard and elsewhere have been studying whether the drug propranolol can dim the emotional response to memories in people with PTSD. In one preliminary trial, investigators found the pill "significantly reduced physiological responses" in the patients. Researchers say the drug works by influencing the reconsolidation of memories, which is the shaping of already-formed -- or consolidated -- memories. In another recent study involving the drug, researchers trained 60 people to associate a picture of a spider with an electric shock. After the conditioning, students who were given propranolol before seeing the picture were not startled, while the other students were.

OTHER METHODS: Researchers are also studying the effects of other drugs for memory editing. Some of these therapies include painkillers, anti-nausea drugs and RU486, which is best known as the "abortion drug."

FOR MORE INFORMATION, CONTACT:
Ronald Najman, Communications and Special Projects
SUNY Downstate Medical Center
Brooklyn, NY
(718) 270-2696
ron.najman@downstate