This study aims to provide evidence that SSRIs facilitate cytoarchitectonical restructuring. In addition to expanding the investigators current knowledge on the trophic effects of SSRIs, the results of this study will also elucidate interactions between the serotonergic system and changes to neuronal networks during learning as well as their behavioral consequences. By probing the neurobiological correlates of the antidepressant and anti-anxiety effects of SSRIs, this study will provide a rationale for targeted interventions that harness the neuroplasticity enhancing properties of SSRIs to facilitate therapeutic processes.