Saturday, 21 Mar, 2009 Health & Fitness

Is Stress Harmful For The Brain?


In the early 1990's, J. Douglas Bremner and his colleagues from the National Center of Studies Upon Posttraumatic Disturbances have discovered that the volume of the hippocampus is decreased among war veterans, who had suffered from posttraumatic stress.

However, the importance of this discovery was doubtful at the beginning, since scientists from War–Medicine Academy of Harvard have linked the small volume of the hippocampus with the risk of the development of posttraumatic stress among twins. But the twins who had taken part in the research were submitted to frequent traumas of the brain, which were leading to changes in other brain areas, for example in the frontal part of the cortex.

According to previous studies, made by Robert Sapolski from the University of Stanford, stress brings leads to the destruction of neurons. Bruce McEven and his colleagues from the University of Rockefeller showed that stress destroys the bonds between the neurons.

Heisan and his colleagues from the University of Yells had worked with mice submitted to posttraumatic stress. The decreasing number of synapses in the hippocampus as a result of stress had led to the development of depression. Thus, the changes in the structure of neurons had an influence on behavior.

"Our studies are based on the fact that synapses have an important role in sudden changes of mood. That's why it is essential to be able to restore synapse bonds in a short period of time", Heisan says.

Still, the decreased cortex volume in patients with posttraumatic syndrome is not linked to synapses.

According to experts, the information received as a result of experiments on animals had showed that posttraumatic stress can be caused by the loss of bonds between neurons. It is most likely that posttraumatic stress and a small trauma of the brain are two different, but related factors, which influence the state of soldiers who are submitted to stress during war. Still more research is required on this subject.

Posted by summer_rain

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