Published in the journal Scientific Reports, researchers report that a TBI causes changes in a brain region called the amygdala; and the brain processes fear differently after such an injury. The researchers studied the amygdala, which is known to be crucial in learning fear. People with anxiety disorders have increased activity in the amygdala, and PTSD has been linked to increased activity in the amygdala.
Another new discovery the researchers report is that after the traumatic brain injury, the brain processes sounds from a more primitive part of the brain—the thalamus—than from a more sophisticated, highly evolved area of the brain—the auditory cortex. The thalamus provides a more simplistic, crude representation of sound than the auditory cortex.
The study, done in the laboratory using rats, raises the question of whether it is possible to get the brain’s amygdala back to normal following a concussion-like injury, perhaps through behavioral therapy or a pharmaceutical.