#MENTAL HEALTH

MOOD-BOOSTING BACTERIA

Beneficial bacteria injections can kick-start antiinflammatory effects in the brain, making it more resistant to the harmful effects of stress. Researchers at the University of Colorado have found that injecting rats with Mycobacterium vaccae boosted the levels of the anti-inflammatory protein interleukin- 4 in the hippocampus – a brain region responsible for modulating cognitive function, anxiety and fear. The rats who received the injections were much less anxious when placed in stressful situations, they say. The researchers are now working on a study to investigate if a different bacterial strain, Lactobacillus reuteri, can help returning war veterans to cope with the effects of post-traumatic stress disorder.

NATURE 1, DEPRESSION 0

Taking a walk in nature may help to reduce the risk of suffering depression, according to researchers at Stanford University. The team had two groups of volunteers walk for 90 minutes, one in a grassland area scattered with oak trees and shrubs, the other alongside a traffic-heavy four-lane road. The researchers found little difference in physiological conditions between the groups, but marked changes in the brain. Neural activity in the subgenual prefrontal cortex, a brain region active during repetitive thought focused on negative emotions, was markedly decreased in the people who enjoyed the grassland walk compared to those who strolled along the busy road.