Neural plasticity to stress and antidepressant treatment

Adaptations at the cellular and molecular levels in response to stress and antidepressant treatment could represent a form of neural plasticity that c ontributes to the pathophysiology and treatment of depression. At the cellu lar level, atrophy and death of stress-vulnerable neurons in the hippocampu s, as well as decreased neurogenesis of hippocampal neurons, has been repor ted in preclinical studies. Clinical studies also provide evidence for atro phy and cell death in the hippocampus, as well as the prefrontal cortex. It is possible that antidepressant treatment could oppose these adverse cellu lar effects, which may be regarded as a loss of neural plasticity, by block ing or reversing the atrophy of hippocampal neurons and by increasing cell survival and function. The molecular mechanisms underlying these effects ar e discussed, including the role of the cAMP signal transduction cascade and neurotrophic factors. (C) 1999 Society of Biological Psychiatry.