Traumatic events (trauma), such as divorce, job loss, death of a loved one can harm mental health. People are easy to get depression and anxiety disorders during these periods.
However, trauma is a normal part of life, and it is thought that the best way to deal with it is to learn useful coping strategies.
But now scientists offer a good news: the brain itself can reduce cell production to help cope with trauma and avoid mental illness. The finding is published in Journal of Neuroscience.
Researchers wanted to know the brain process underlying adaptation to social instability. They first formed a dominance hierarchy in rats and then destabilize the hierarchy.
In the wild, the most aggressive rat emerges as the dominant. This arrangement can reduce fighting and keep the whole group socially stable. However, the stability can be disrupted when the dominant rat is old, ill or dead, a rogue rat joins the group, or the habitat condition changes.
In the study, researchers first formed a dominance hierarchy in each of the two rat groups. After that, they switched the dominant rats between the two groups to disrupt the hierarchy.
Rats’ behaviors during hierarchy formation, disruption, and re-emergence were recorded. The neuron activity in their brain was also examined.
Researchers found that compared with rats in a stable hierarchy, rats in the disrupted group produced less new neuron in their brain. This reduction occurred in the hippocampus, a brain area related to new memory formation and anxiety/stress regulation.
Interestingly, hierarchy disruption changed rats’ social behavior but did not impact their mental and cognitive skills. These rats developed a preference for familiar rats over novel rats in the group, but they did not have memory impairments or increased anxiety.
Researchers suggest that the suppression of neuron production in the hippocampus make these rats prefer familiar things. This may be a good cope strategy to adapt to the disrupted situation and avoid mental illness.
To validate the view, researchers suppressed neuron production in the hippocampus in rats from the stable group. They found that these rats showed behavior similar to the disrupted rats.
To summarize, these results confirm that the brain has its own cope strategy to deal with unstable situations and protect itself from harm.
Citation: Opendak M et al. (2016). Lasting Adaptations in Social Behavior Produced by Social Disruption and Inhibition of Adult Neurogenesis. Journal of Neuroscience, 36: 7027-7038. doi: 10.1523/JNEUROSCI.4435-15.2016.
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