Amygdala activation during acquisition of fear learning in PTSD. There was an increase in amygdala activation during acquisition of conditioned fear learning in women with PTSD related to early childhood abuse. Yellow areas in the amygdala show areas …
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Effect of trauma on the ventromedial prefrontal cortex
Severe emotional trauma causes lasting changes in the ventromedial prefrontal cortex region of the brain that is responsible for regulating emotional responses triggered by the amygdala.
Specifically, this region regulates negative emotions such as fear that occur when confronted with specific stimuli.
PTSD patients show a marked decrease in the volume of the ventromedial prefrontal cortex and the functional ability of this region.
This explains why people suffering from PTSD tend to exhibit fear, anxiety, and extreme stress responses even when faced with stimuli not connected—or only remotely connected—to their experiences from the past.
Effect of trauma on the amygdala
Trauma appears to increase activity in the amygdala. This region of the brain helps us process emotions and is also linked to fear responses. PTSD patients exhibit hyperactivity in the amygdala in response to stimuli that are somehow connected to their traumatic experiences.
They exhibit anxiety, panic, and extreme stress when they are shown photographs or presented with narratives of trauma victims whose experiences match theirs, or if they listen to sounds or words related to their traumatic encounters.
What is interesting is that the amygdala in PTSD patients may be so hyperactive that these people exhibit fear and stress responses even when they are confronted with stimuli not associated with their specific trauma, such as when they are simply shown photographs of people exhibiting fear.
The hippocampus, the ventromedial prefrontal cortex, and the amygdala are part of the neural circuitry that mediates stress. The hippocampus facilitates appropriate responses to environmental stimuli, so the amygdala does not go into stress mode unecessarily.
The ventromedial prefrontal cortex regulates emotional responses by controlling the functions of the amygdala. It is thus not surprising that when the hypoactive hippocampus and the functionally-challenged ventromedial prefrontal cortex stop pulling the chains, the amygdala gets into a tizzy. (This explains a lot)
Hyperactivity of the amygdala is positively related to the severity of PTSD symptoms. The aforementioned developments explain the tell-tale signs of PTSD—startle responses to the most harmless of stimuli, frequent flashbacks, and intrusive recollections.
Researchers believe that the brain changes caused by PTSD increase the likelihood of a person developing other psychotic and mood disorders. Understanding how PTSD alters brain chemistry is critical to empathize with the condition of the victims and devise treatment methods that will enable them to live fully and fulfill their true potential.
But in the midst of such grim findings, scientists also sound a note of hope for PTSD patients and their loved ones. According to them, by delving into the pathophysiology of PTSD, they have also realized that the disorder is reversible. The human brain can be re-wired. In fact, drugs and behavioral therapies have been shown to increase the volume of the hippocampus in PTSD patients. The brain is a finely-tuned instrument. It is fragile, but it is heartening to know that the brain also has the amazing capacity to regenerate.
(I would love to get a functional mri of my brain)
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PTSD - A Way Out.com 