Mammalian Target of Rapamycin Signaling Pathways and Depression

Depression is a complicated psychiatric illness with severe consequences. Despite recent advanced achievements of molecular neurobiology, pathophysiology of depression has not been well elucidated. Among new findings of pathophysiology of depression, the possible fast antidepressant effect by N-methyl-D-asparate receptor antagonist, such as ketamine, is regarded as a promising treatment target of depression. Ketamine stimulates the mammalian target of rapamycin (mTOR) signaling pathway and activation of mTOR signaling pathway may be a key mechanism of the antidepressant effect of ketamine. Thus, this review describes the role of mTOR signaling in the pathophysiology of depression and developing a new treatment target of depression.

Role of p11 (S100A10) in Depression and Antidepressant Effects

p11 protein (S100A10) is downregulated in depressive-like states of human and rodent. Antidepressant drug treatment increases p11 levels in rodent models. We reviewed studies demonstrating that p11 levels are regulated in depression and by antidepressant treatment and that p11 upregulation exerts antidepressant effects. Current studies on p11 underscore the importance of p11 as a potential antidepressant target.

Neuroglia and Mood Disorder

Mood disorder is a common psychiatric illness with a high lifetime prevalence in the general population. A serious problem such as suicide is commonly occurring in the patients with depression. Till now, the monoamine hypothesis has been the most popular theory of pathogenesis for depression. However, the more specific pathophysiology of depression and cellular molecular mechanism underlying action of commercial antidepressants have not been clearly defined. Several recent studies demonstrated that glial cells, especially astrocytes, are a promising answer to the pathophysiology of depression. In this article, current understanding of biology and molecular mechanisms of glial cells in the pathology of mood disorder and new research on the pathophysiology of depression will be discussed.