TCD finding in stress study could aid understanding of Alzheimer's


An explanation of the effect of stress on memory loss has been established by a team of neuroscientists at Trinity College Dublin. The researchers, whose results are published today in a leading US scientific journal, found that memory is adversely affected by additional protein, which is produced in the brain when stress levels of hormones are present.

Prof Michael Rowan, one of the scientists, said the finding could form the basis of breakthroughs in the understanding and treatment of memory disturbances in diseases such as Alzheimer's.

He said the protein, which has yet to be identified, acts as "a switch" in controlling the flow of information in the brain. The study shows that higher levels of the protein weaken rather than strengthen connections between nerves which are used for memory.

Prof Rowan said the finding suggests that memory loss could be combated by either reducing the level of hormones produced during stress or by blocking the effect of the hormones. "Which method would be of benefit, if either, is open to research," he said.

The finding was made during a research project on memory at Trinity's department of physiology. Prof Rowan, a lecturer at the department, carried out the study along with Prof Roger Anwyl of the department of pharmacology and therapeutics, and Mr Lin Xu, a visiting researcher from the Chinese Academy of Sciences at Kunming.

It is to be published today in the noted scientific publication Proceedings of the National Academy of Science, USA.

Prof Rowan said they will not know the full implications of the discovery until it is applied in clinical tests. At present, the team is working on collaborative projects with St James's Hospital in Dublin, looking at treatments for patients suffering memory loss as a result of Alzheimer's or depression.

Previous research had shown that high levels of stress impaired memory, with the exception of emotional memory which is enhanced by stress. What makes the Trinity team's research new is that it explains for first time the role of natural steroids - such as cortisol - released during stress in memory processes.

Prof Rowan said it also provides a new impetus for scientists to develop drugs which can be used in the treatment of Alzheimer's disease and other conditions involving memory loss.