Scripps Florida scientists win grant to uncover ways to erase toxic PTSD memories

Scientists from the Florida campus of The Scripps Research Institute (TSRI) have been awarded $2.3 million from the Department of Health and Human Services of the National Institutes of Health to better understand how memories are stored in the hopes of eventually being able to treat posttraumatic stress disorder (PTSD) by erasing traumatic memories without altering other, more benign ones.

Courtney Miller, a TSRI associate professor, is the principal investigator for the new five-year study.

"We hope this new study will make a significant contribution to the goal of developing new and more effective treatments for mental illness," Miller said.

While literally thousands of mechanisms for how a memory initially forms have been identified, only a few mechanisms are known for how the brain stores these memories for weeks to years. To produce a memory, a lot has to be done, including the alteration of the structure of nerve cells via changes in the dendritic spines—small bulb-like structures that receive electrochemical signals from other neurons. Normally, these structural changes occur via actin, the protein that makes up the infrastructure of all cells.

Miller is investigating the possibility that microRNAs, naturally occurring small RNAs that act to suppress the production of proteins, may be capable of coordinating the complexity required for the brain to maintain this actin-based structural integrity of a long-lasting memory.

"Our study will investigate the microRNA profile of a PTSD-like memory, with the idea that the persistence of a traumatic memory is maintained by the recruitment of a unique set of microRNAs within the amygdala—the brain's emotional memory center and a critical participant in PTSD," Miller said.

An understanding of how the brain actually stores these toxic memories should result in the development of new targets that can then be exploited to selectively target harmful memories, as in the case of PTSD, or to preserve fading memory, such as with age-related cognitive decline.

In 2013, Miller and her colleagues were able to erase dangerous memories associated with drugs of abuse in mice and rats, without affecting other more benign memories. That surprising discovery, published in the journal Biological Psychiatry, pointed to a clear and workable method to disrupt unwanted memories while leaving others intact.

Provided by The Scripps Research Institute