Research Helps to Explain Depression
Depression affects many TBI survivors, but, until now, no one knew why a person became depressed. Basic research at the Wiezmann Institute of Science in Israel has resulted in revealing an important part of the pathway that regulates a key chemical (serotonin) responsible for depression and anxiety. The scientists identified a small RNA molecule (microRNA miR135) that determines whether a person becomes depressed or not.
MicroRNAs were recently discovered. In this case, microRNA miR135 regulates the level of serotonin. The regulation of serotonin by miR135 was proven in mice genetically engineered to have high or low levels of miR135. As a result, the level of serotonin was affected. Too little serotonin resulted in signs of depression and anxiety in mice. Humans who were depressed had unusually low levels of miR135. Higher miR135 levels were observed in people who were not depressed. Such people are known to have higher levels of serotonin. The ability to measure the level of miR135 in people means better diagnosis of depression. It also means it will be possible to screen for therapeutic drugs that can boost the miR135 level (and therefore serotonin level). (Full story)