11-13 In contrast to the atrophy of hippocampus, recent studies demonstrate that chronic stress causes hypertrophy of neurons in the amygdala.14 This study found chronic immobilization stress increased the dendritic arborization of pyramidal neurons in the basolateral amygdala, but decreased dendrite length and branching in the CA3 pyramidal neurons of the hippocampus. Hypertrophy of the amygdala could underlie increased learning and memory as a result of stressinduced emotional arousal, and may be

relevant to the pathophysiology of http://www.selleckchem.com/products/nutlin-3a.html stress-related disorders, including anxiety, posttraumatic stress, and depression. Increased arborization of neurons in the amygdala Inhibitors,research,lifescience,medical could thereby enhance emotional states or disrupt normal processing of emotional responses. Figure 1. Model of hippocampal plasticity showing structural alterations in response to stress: atropy of CA3 pyramidal neurons and decreased neurogenesis of dentate gyrus granule cells. Stress results in powerful effects on the hippocampus, partly because of the … Inhibitors,research,lifescience,medical Stress decreases neurogenesis in the adult hippocampus In addition to regulation of the morphology of neurons in the hippocampus, stress influences the number of newborn neurons or neurogenesis

Inhibitors,research,lifescience,medical in the adult hippocampus15,16 (Figures 1 and 2.) The hippocampus is one of two brain regions where neurogenesis continues to occur in adult organism (the other region is in the subventricular zone). In the hippocampus, neural progenitor cells are found Inhibitors,research,lifescience,medical in the subgranular zone, between the granule cell layer and the hilus. These cells give rise to newborn cells that migrate into the granule cell layer and mature into neurons with the morphological and physiological characteristics of adult granule cells.17 Interestingly, the process Inhibitors,research,lifescience,medical of neurogenesis is highly regulated by a variety of stimuli and can be considered a form of neural plasticity. For example, enriched environment, exercise, and learning increase neurogenesis, while aging and exposure to drugs of abuse decrease neurogenesis.15,16,18

Figure 2. Model demonstrating the regulation of adult neurogenesis in the hippocampus. Neural progenitor cells are restricted to the subgranular zone (SGZ) that is located between the granule cell layer (GCL) and hilus. These progenitor cells give rise to newborn … In addition to these factors, AV-951 stress also results in a dramatic downrcgulation of neurogenesis in the hippocampus.10,18 Exposure to just a single stressor is sufficient to significantly decrease neurogenesis in the adult hippocampus. Adult neurogenesis is decreased by different types of stress, including subordination stress,19 predator odor,20 maternal separation,21 and footshock.22 In addition, exposure to inescapable stress in the learned helplessness model of depression decreases adult neurogenesis and this effect correlates with behavioral despair in this model.