A new study suggests that exercise leads to elevated galanin levels – which in turn helps the brain’s stress response, giving more resilience. Tom Walker reports

Astudy by researchers at Emory University in the US has shown exercise can strengthen the brain’s resilience to stress, by elevating levels of the neuropeptide, galanin.

The research team studied two groups – a sedentary group and one that exercised regularly. They measured anxious behaviour in the test subjects 24 hours after an artificially created stressful event.

Those who exercised regularly showed less anxious behaviour after the stressful event compared to those that didn’t exercise.

Elevated levels of galanin
The exercise group had elevated galanin levels in the locus coeruleus, a cluster of neurons in the brainstem that are involved in the stress response.

Crucially, the amount of time spent exercising correlated with the amount of galanin in the locus coeruleus, which in turn correlated with the degree of stress resilience.

The findings could help explain the link between exercise and relieving stress – which, apart from a plethora of anecdotal evidence, isn’t well understood by scientists.

More reliable than drugs
“Increased physical activity is associated with stress resilience in humans, but the neurobiological mechanisms underlying this effect are not clear,” explained the researchers.

“The neuropeptide galanin has been implicated in stress-related neuropsychiatric disorders in humans,” said researchers.

“While pharmacological treatments for these disorders are ineffective for many individuals, the research study found that physical activity is beneficial,” said the research team.

“This study shows that genetic overexpression of galanin in noradrenergic neurons causes resilience to a stressor and the anxiogenic effects of optogenetic locus coeruleus activation.

“These findings support a role for chronically increased noradrenergic galanin in mediating resilience to stress,” they concluded.

• The study, titled Chronic environmental or genetic elevation of galanin in noradrenergic neurons confers stress resilience, was published in the Journal of Neuroscience.

Find out more about this research at: www.HCMmag.com/galanin