Researchers from Munich’s Max Planck Institute of Psychiatry have been exploring how stress can influence our cognitive performance. As part of their research they’ve been able to identify a brain mechanism in mice that goes some way to explaining why their cognitive performance takes a nose-dive after exposure to social stress. They hope that their findings will help to give us a better understanding of cognitive disorders, and to inform the development of suitable treatments for cognitive decline in humans.
To see how stress affects the brain, let’s have a look at its structure. The region responsible for mental activity, recognition and perception is the prefrontal cortex. It springs into action whenever we want to respond flexibly to a situation, do a number of things simultaneously or to make plans for the future; processes which can all lead to stress. As we go through these processes, each reaction in the prefrontal cortex is controlled by corticotropin-releasing factor or CRF, a peptide hormone and neurotransmitter involved in the stress response.
As we don’t yet know the exact role played by CRF, the Munich scientists wanted to find out what happens in the brain during these periods of stress. By exposing mice to acute social stress, the scientists noticed a significant cognitive decline in the mice after several hours. The mice were unable to negotiate a test maze or remember sequences of events learned earlier in the day. To explore this further, the researchers used a CRF antagonist to block the action of the peptide. Once treated with this drug, the mice were able to perform well in the tests, despite having been through periods of stress prior to being tested.
The identification of the mechanism responsible for the reduction in performance following periods of stress is significant, and will help future researchers to understand more about how stress can affect our thoughts, our feelings and our perceptions. Furthermore, as this mechanism is similar in both mice and humans, it’s likely that the team’s findings can be transferred to humans, and make it possible to develop new approaches for suitable treatments and medications.
The study was published online in an April edition of the journal Biological Psychiatry.