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December 04, 2008

Scientists Explore the Neuroanatomy of Depression

In an article in the November issue of the Journal of Neuroscience researchers Michael Koenigs, Edward D. Huey, Matthew Calamia, Vanessa Raymont, Daniel Tranel, and Jordan Grafman submitted an article entitled “Distinct Regions of Prefrontal Cortex Mediate Resistance and Vulnerability to Depression”. The study looked at the anatomy of the prefrontal cortex and discovered the different influences certain sub regions have on depression.

The study started from analysis of brain images of a “depressed brain”, that is a brain of a person with some kind of depression disorder. This analysis led researchers to the conclusion that there are abnormal patterns of activity in the prefrontal cortex of the depressed brain. It has long been known that the prefrontal cortex is associated with personality and mood and therefore mood disorders, but study of specific sub nuclei has been limited.

In this particular paper Koenigs et al. looked at patients with brain lesions (damage to specific parts of the brain). They focused on subjects with lesions in the ventromedial prefrontal cortex (vmPFC) and the dorsolateral prefrontal cortex (dlPFC), two sections that showed particularly abnormal behavior on the brain scan. The images below show the location of the vmPFC and the dlPFC in the human brain. The first image shows the vmPFC highlighted in pink and the second image shows the dlPFC in green.

source: Wikipedia.com

source: Google Images

The subjects with damage to the vmPFC were significantly less likely to have depression. This shows that vmPFC likely plays a strong role in the susceptibility of one becoming depressed, on the other hand a damaged dlPFC increased the likelihood of having depression in turn showing that the dlPFC could be involved in resistance to depression.

While these findings may seem minor at first look in reality they are hugely beneficial to the understanding and future research on depression. There are many factors involved in depression, so much so that the research can be overwhelming. However, by specifying two sub regions that play dramatic roles in the disorder researchers can focus their study and attempt to develop more complex studies to understand what goes wrong in these regions causing depression. Future studies will focus on these regions and what can be done to change the abnormalities in order to treat and possibly prevent depression.

Posted by horr at December 4, 2008 03:06 AM