April 4, 2009— -- A new drug-free therapy wipes away fearful memories in rats and humans. The simple treatment might eventually help patients with post-traumatic stress disorder, say researchers.
The new procedure relies on a quirky property of memories called reconsolidation. The process of jogging a memory – with an emotional or sensory jolt, for instance – seems to make it malleable for a few hours.
Potent drugs that block brain cells from making new proteins can erase fearful memories during this window. But these chemical are toxic, and wholesale memory erasure could do more harm than good, says Karim Nader, a neuroscientist at the McGill University in Montreal, Canada, who performed some of the drug studies.
In search of a gentler way to block fearful memories, Marie Monfils, a neuroscientist at the University of Texas in Austin, tweaked a therapy sometimes used to treat PTSD, called extinction.
Here, doctors repeatedly deliver threatening cues – gun shots, for instance – in safe environments in hopes of drowning out the fearful associations.