releasing factor (CRF) and
serotonin reuptake inhibitor
improvements in memory.
counteracting the effects o
access the ECNRU website.
studies are conducted at the Emory Clinical Neuroscience Research Unit (ECNRU).
Research is supported by the NIH, VA, and private foundations. Research fellows
are supported by the NIH T32 funded Training Program in Neuroimaging Sciences (TPINS).
Our research has uncovered changes in the brain in posttraumatic stress disorder (PTSD) and depression.
Studies show changes in brain areas that mediate mood, emotion, and the fear response, including the
amygdala, hippocampus, and prefrontal cortex. The hippocampus is very sensitive to stress and our imaging
studies have shown smaller volume of the hippocampus (which we believe is due to stress induced damage)
and dysfunction of the hippocampus when it is performing memory tasks (which is the function of the
hippocampus). Other studies show that the amygdala, a brain area that plays a critical role in fear
responses, has an increase in activity during the acquisition of fear learning (classical fear conditioning)
or with exposure to trauma related odors (like diesel in veterans). It is the job of the medial prefrontal
cortex to turn off the amgydala, or to extinguish fear memories by inhibition of fear responses mediated by the
amygdala, and brain imaging studies using positron emission tomography showed that PTSD patients when
exposed to a reminder of childhood abuse or combat had a failure to activate the medial prefrontal cortex.
We have also shown that PTSD patients have problems with memory based on neuropsychological testing.
PTSD is also associated with changes in neurohormonal systems, including elevations of corticotropin
exaggerated cortisol and norepinephrine responses to stressors. Treatment with either the selective
paroxetine or the anti epilepsy drug, phenytoin, resulted in an increase in hippocampal volume and
These drugs are known from animal studies to result in an increase in nerve growth in the hippocampus,
f stress. For more information on research or for copies of papers and questionnaires