BOSTON – A study by Massachusetts Institute of Technology neuroscientists has shown that the brain circuit controls how memories are linked with positive or negative emotions – and that the emotional association with specific memories could be reversed by using optogenetics.
Optogenetics is a technique that manipulates nerve cells by using light. It was pioneered by Karl Diesseroth at Stanford University.
The MIT study using the technique is described in the Aug. 28 issue of Nature.
The MIT research shows that a neuronal circuit connecting the hippocampus and the amygdala functions in a critical role in associating emotion with memory. These researchers are suggesting that new drugs can be developed to target the circuit and be used eventually to treat conditions such as post-traumatic stress disorder.
“In the future, one may be able to develop methods that help people to remember positive memories more strongly than negative ones,” said the senior author of the paper, Susumu Tonegawa.
Tonegawa is the Picower Professor of Biology and Neuroscience and director of the RIKEN-MIT Center for Neural Circuit Genetics at MIT’s Picower Institute for Learning and Memory.
Researchers at the University of California at Davis Center for Neuroscience and Department of Psychology also have used light to erase specific memories in mice. They have now proved a basic theory of how different parts of the brain work together to retrieve episodic memories.
Dr. Aviva D. Wertkin, ND, who practices at Naturae Medical in Brattleboro, Vermont, said therapies involving eye movement and light are already being used to treat PTSD patients.
“It actually uses a visual component called EMDR, or Eye Movement Desensitization and Reprocessing,” she said. “It’s not normally done by naturopathic doctors, but it is done by social workers and psychotherapists who treat PTSD … so we all should know about this.”