Stress. Nobody is immune to it. More people than ever are feeling the relentless pressure of busy lives and it can take its toll. But it seems some people are able to cope with this problem much better than others. Some individuals are resilient, while others succumb to despair. The reason, scientists have discovered, may be all in the brain.
The brain activity of mice placed in stressful situations was mapped, and mice that showed helplessness had vastly different brain activity from those that displayed resilience. Certain patterns were revealed in the stressed brain, which allowed the scientists to identify brain areas that might have a critical role to play in stress-induced depression. Looking at these brain activities the study, published in Frontiers in Neural Circuits, opens up possibilities for identifying new targets for the treatment of depression.
With the exception of a few brain areas, "mice showing 'helpless' behavior had an overall brain-wide reduction in the level of neuronal activation compared with mice showing 'resilient' behavior. In addition, the helpless mice showed a strong trend of having higher similarity in whole-brain activity profile among individuals, suggesting that helplessness is represented by a more stereotypic brain-wide activation pattern," the authors of the study explain.
Helpless behavior in the face of stress is distinctly recognizable in the brain and common to those animals displaying helplessness.
Moreover, helpless mice had significantly lower levels of overall brain activity, including in the prefrontal cortex — the region associated with organizing thoughts and actions, and which has been implicated in mood or anxiety disorders. The helpless group also showed lower brain activation in areas vital for processing emotion and motivation, areas important for defensive behavior, those key for stress-coping and those associated with learning and memory.
The locus coeruleus area of the brain also lit up more in helpless mice than resilient ones. The scientists believe that investigating this area further and determining the effect it has in stress-induced depression could translate into future treatments.