Being stressed CAN be good for you – it boosts memory
Chronic stress has been shown to increase the risk of heart attack and compromise the immune systemBut short-lived stress primes the brain for improved performance – most notably boosting memoryResearchers say it encourages stem cells in the brain to turn into new nerve cells that boost mental agility

By
Anna Hodgekiss

PUBLISHED:

11:24 GMT, 17 April 2013

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UPDATED:

11:43 GMT, 17 April 2013

Overworked and stressed out Look on the bright side – some stress is good for you.

While chronic stress can increase the risk of heart attack and compromise the immune system, researchers have found that short-lived stress primes the brain for improved performance – most notably boosting memory.

In studies on rats, the researchers
found that significant, but brief stressful events caused stem cells in
the brains of rats to turn into new nerve cells that, when mature
two weeks
later, improved their mental performance.

Short-lived stress can boost mental performance, most notably boosting memory

Short-lived stress can boost mental performance, most notably boosting memory

'You always think about stress as a
really bad thing, but it's not,' said Daniela Kaufer, associate
professor of integrative biology at the University of California,
Berkeley.

'Some amounts of stress are good to push you just to the level
of optimal alertness, behavioral and cognitive performance.

'I think intermittent stressful events
are probably what keeps the brain more alert, and you perform better
when you are alert,' she said.

Much research has demonstrated that
chronic stress elevates levels of stress hormones, which
suppresses the production of new neurons in the hippocampus, impairing
memory.

It's also known that chronically elevated
levels of stress hormones increasing
the risk of obesity, heart disease and depression.

But less is known about the effects of acute stress, Dr Kaufer said, and studies have been conflicting.

But chronic stress elevates levels of stress hormones, impairing memory

But chronic stress elevates levels of stress hormones, impairing memory

To clear up the confusion, the researchers subjected rats to what, to them, is acute but short-lived stress – being locked in their cages for a few hours.

This led to stress hormone (corticosterone) levels as high as those from chronic stress, though for only a few hours.

But it also doubled the proliferation of new brain cells in the hippocampus,.

The researchers also found that the stressed rats performed better on a memory test two weeks after the stressful event, but not two days after the event.

Using special cell labeling
techniques, the researchers established that the new nerve cells
triggered by the acute stress were the same ones involved in learning
new tasks two weeks later.

'In
terms of survival, the nerve cell proliferation doesn't help you
immediately after the stress, because it takes time for the cells to
become mature, functioning neurons,' said Dr Kaufer.

'But
in the natural environment, where acute stress happens on a regular
basis, it will keep the animal more alert, more attuned to the
environment and to what actually is a threat or not a threat.'

However the researchers noted that exposure to acute, intense stress can sometimes be harmful, leading, for example, to post-traumatic stress disorder.

'But I think the ultimate message is an optimistic one, concluded Dr Kaufer. 'Stress can be something that makes you better, but it is a question of how much, how long and how you interpret or perceive it.'

The study is published in the online journal eLife.