Memory loss caused by inflammation in the brain may be treatable and reversible, a new study has found.
The study, led by Dr. Beverley Orser, Staff Anesthesiologist at Sunnybrook Health Sciences Centre and Dr. Dian-Shi Wang, Research Associate in the Department of Physiology at the University of Toronto, found that memory loss could be reversed by pharmacologically targeting "memory-blocking" receptors in the hippocampus, a part of the brain that regulates learning and memory.
"Inflammation in the brain has been linked to memory loss and cognitive disorders, including Alzheimer's disease. When inflammation has occurred after an infection, injury, stroke, or even after a surgical procedure, the resulting memory loss can be profound and prolonged. Currently, there is no treatment for post-surgery memory loss," says Dr. Orser, who also works in the Department of Anesthesiology and Physiology at the University of Toronto.
Dr. Orser's team found that a key inflammatory factor IL-1β activates a protein she refers to as a "memory blocking" receptor, α5GABA (the gamma-aminobutyric acid A receptor, alpha 5). Increasing the activity of the memory blocking receptor causes memory deficits in mice; however, once mice were treated with a drug that inhibits the memory blocking receptor, memory loss was reversed.
The results of the study provide insights into the cause of memory loss and a possible treatment associated with inflammation, a needed event in the healing process. "Although inflammation leads to memory loss, dampening inflammation with drugs such as steroids results in poor wound healing. We sought to identify the specific downstream target in the brain that causes memory loss which accompanied inflammatory events," says Dr. Orser.
Dr. Orser hopes these findings will be applied to a clinical trial in the near future, with a study focusing on those who have experienced cognitive deficits after surgery.
The study, published online today in advance of publication in the September 2012 issue of the journal Cell Reports, was funded by the Canadian Institutes of Health Research.