Process linking stress to memory loss found
07 April 2011
Medical Research Council funded scientists have shown how two receptors in aging brains react to a stress hormone called cortisol, which has been linked to increasing forgetfulness as we age. The development could help research into treatments for age-related memory disorders.
The study found that one receptor is activated by low levels of cortisol, which helps memory. When cortisol levels increase, a second receptor is activated, activating genes and brain processes that contribute to memory impairment. Receptors are proteins found at the edges of our cells, and are the structures which enable cells to respond to chemical signals in our body.
The University of Edinburgh based researchers observed the effect in mice, where high levels of cortisol in aged mice made them less able to remember how to navigate a maze. The memory recall problem was reversed when the second receptor was blocked, a finding which could have implications for memory-loss treatments.
Professor Chris Kennard, Chairman of the MRC's Neuroscience and Mental Health Board, which funded the research, said:
“This research highlights some interesting, original concepts relating to how memory loss occurs in old age. With people living ever longer, the MRC is really focussing on research which allows elderly people not just to survive, but also to stay healthy.”
Dr Joyce Yau, who led the study, said:
“While we know that stress hormones affect memory, this research explains how the receptors they engage with can cause a switch from good memory to bad memory in old age. We now know that lowering the levels of these stress hormones will prevent them from activating a receptor in the brain that is bad for memory. Understanding the mechanisms in the brain which affect memory as we age will help us to find ways to combat conditions linked to memory loss.”
The study was published in the Journal of Neuroscience.
