25,26 Studies have not been able to document Volasertib clinical trial changes in hippocampal volume in normal populations during this period.27 After menopause in women at about the age of 50, however, there are changes in reproductive hormones, such as decreased levels of estrogen. Since estrogen promotes neuronal branching in brain areas such as the hippocampus,28 a loss of estrogen may lead to changes in neuronal structure. Although the effects Inhibitors,research,lifescience,medical of menopause on the brain have not been well studied, it is known that sex hormones also affect brain function and circuitry29; therefore,
the changes in sex hormones with menopause will presumably affect brain function, as well as possibly structure. There is some evidence in super-elderly individuals (age >70) for modest reductions in hippocampal Inhibitors,research,lifescience,medical volume with late stages of aging.27,30 More robust findings have included increased ventricular volume and reduction in gray matter, temporal lobe, and cerebellum volumes with normal aging, that begins before the age of 70.25,27,31-33 Inhibitors,research,lifescience,medical Therefore, trauma at different stages in life will presumably have different effects on brain development. The few studies that have looked at this issue do suggest that there are differences in the effects of trauma Inhibitors,research,lifescience,medical on neurobiology,
depending on the stage of development at which the trauma occurs. Studies in this area, however, have been limited. Neurobiology of PTSD PTSD is characterized by specific symptoms, including intrusive thoughts, hyperarousal, flashbacks, nightmares, and sleep
disturbances, changes in memory and concentration, and startle responses. Symptoms of PTSD are hypothesized to represent the behavioral manifestation of stress-induced changes in brain structure and function. Stress results in acute and chronic changes in neurochemical systems and specific brain regions, which Inhibitors,research,lifescience,medical result in longterm changes in brain “circuits,” involved in the stress response.34-37 Brain regions tuclazepam that are felt to play an important role in PTSD include hippocampus, amygdala, and medial prefrontal cortex. Cortisol and norepinephrine are two neurochemical systems that are critical in the stress response (Figure 1.) Figure 1. Lasting effects of trauma on the brain, showing long-term dysregulation of norepinephrine and Cortisol systems, and vulnerable areas of hippocampus, amygdala, and medial prefrontal cortex that are affected by trauma. GC, glucocorticoid; CRF, corticotropin-releasing … The corticotropin-releasing factor (CRF)/hypothalamic-pituitary-adrenal (HPA) axis system plays an important role in the stress response.