Stress Hormones Affect Your Memory

After we reach 40 most of us find it harder and harder to focus on tasks and keep things in our short-term memory long enough for to move them to long-term memory. What neuroscientists (scientists who study the brain) have found that this aging problem is not your fault, but a natural part of aging. Is there any way to change it? Absolutely!

Research conducted at the University of Edinburgh, and published in the Journal of Neuroscience, shows a link between the stress hormone cortisol and the ability of an older brain to retain memory. The study went on to explain that there are different levels of cortisol in the brain that turns on or off memory receptors.

The researchers found that lower levels of the hormone increased memory function, while higher levels triggered another receptor that started the process to curb memory retention.

Through the use of laboratory mice, researchers were able to see that the mice were not able to navigate through a simple maze when they were injected with high levels of cortisol, while those with lower levels of the hormone had no difficulty. When they blocked the cortisol in the mice with the higher dose of cortisol, performance was enhanced.

The object of the experiment was to see if stress, driven by the hormone cortisol and sustained over a long period of time actually disrupted memory storage and encoding. If it were possible to block the stress hormone, or at least to adjust the level of the secretion, memory would improve.

Professor Jonathan Seckl was the lead researcher in the study who discovered the role the enzyme 11beta-HSD1, known to be involved in the production of neuronal stress hormones, played in the brain. The enzyme converts inactive cortisone into active cortisol in cells. The researchers experimented with and were able to see the effects of a new synthetic compound that selectively blocks the 11beta-HSD1 enzym’s production and allowed the mice in the maze the ability to complete a memory task.

Seckl described the process in this way: “Normal old mice often have marked deficits in learning and memory just like some elderly people. We found that life-long partial deficiency of 11beta-HSD1 prevented memory decline with aging. But we were very surprised to find that the blocking compound works quickly over a few days to improve memory in old mice, suggesting it might be a good treatment for the already elderly.”

Professor Brian Walker, another scientist on the project, added: “These results provide proof-of-concept that this class of drugs could be useful to treat age-related decline in memory. We previously showed that carbenoxolone, an old drug that blocks multiple enzymes including 11beta-HSD1, improves memory in healthy elderly men and in patients with type 2 diabetes after just a month of treatment, so we are optimistic that our new compounds will be effective in humans. The next step is to conduct further studies with our pre-clinical candidate to prove that the compound is safe to take into clinical trials, hopefully within a year.”

The effects were seen after only 10 days of treatment.

Walker and Dr Scott Webster are leading the drug development program. The 11beta-HSD1 enzyme has also been linked to metabolic diseases like diabetes and obesity. Similar drugs that can block the enzyme’s activity outside of the brain are already under study.

England’s Welcome Trust spokesman, Dr Rick Davis, commented: “Developing drugs that can selectively inhibit this enzyme has been a challenge to the pharmaceutical industry for nearly 10 years. Advancing this compound towards clinical trials takes us a step closer to finding a drug that could have far reaching implications as the population ages.”

About the Author:

Ron White is a memory training expert
Sources: – Age Related Memory Loss Tied to Stress Hormone Receptor in The Brain:

Journal of Neuroscience (2011; 31 (11): 4188 DOI: 10.1523/JNEUROSCI.6145-10.2011)
Science News – Promising Drug Candidate Reverses Age-Related Memory Loss in Mice:
Science Daily – Promising Drug Candidate Reverses Age-Related Memory Loss in Mice:

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