New evidence challenges the conventional wisdom that the brain chemical serotonin is responsible for maintaining mood balance, and that a deficit of serotonin leads to depression.
In a study, scientists report that mice lacking the ability to make serotonin in their brains did not show depression-like symptoms.
The study is published in the journal ACS Chemical Neuroscience.
Donald Kuhn, Ph.D., and colleagues at Wayne State University School of Medicine set out to study what role, if any, serotonin played in the development of depression.
To do this, they developed “knockout” mice that had been genetically altered to prevent the production of serotonin in their brains. Then, scientists ran a battery of behavioral tests on the special mice.
Interestingly, researchers found the mice to be compulsive and extremely aggressive, but didn’t show signs of depression-like symptoms.
Another surprising finding is that when put under stress, the knockout mice behaved in the same way most of the normal mice did. And some of the knockout mice responded therapeutically to antidepressant medications in a similar manner to the normal mice.
These findings further suggest that serotonin is not a major player in the condition, and different factors must be involved, according to the researchers.
If the study is replicated, a new approach for the development of antidepressants may be called for.
Source: American Chemical Society