Why too much stress makes your memory worse as you age

Forgot your keys? High levels of stress worsen memory

Scientists claim to have solved the mystery of how stress contributes to memory loss in old age.

Researchers at Edinburgh University have shown how two receptors in older brains react to the stress hormone cortisol, which has been linked to memory loss in the elderly.

The study found that one receptor was activated by low levels of cortisol, which helped memory.

However, once levels of the hormone were too high they spilled over on to a second receptor, activating brain processes which contribute to memory impairment.

When the receptor linked to poor memory was blocked, the memory recall problem was reversed.

The experiment based on older mice navigating a maze, was published in the Journal of Neuroscience.

The research helps explain why too much stress over a prolonged period interferes with the normal processes in storing everyday memories.

This is despite the fact that a little bit of stress can help us better remember emotional memories.

Dr Joyce Yau said: 'While we know that stress hormones affect memory, this research explains how the receptors they engage with can switch good memory to poorly-functioning memory in old age.'

She added that understanding the mechanisms in the brain, which affect memory as we age, will help find ways to combat conditions linked to memory loss.

The study was funded by the Medical Research Council. 

Professor Chris Kennard, of the MRC, said: 'This research highlights some interesting, original concepts relating to why 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.'

The researchers are looking at a new chemical compound which blocks an enzyme, known as 11beta-HSD1, which helps produce stress hormones within cells.

They hope this could be used to develop a drug treatment to slow the normal decline in memory associated with ageing, or even improve memory in people who are very old.

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