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This small nucleus contains almost half of all the brain neurons that use norepinephrine as a neurotransmitter. The locus coeruleus also projects its axons to those parts of the brain that may be associated with panic disorders (the amygdala, hippocampus, septum, cortex, brainstem, reticular formation, etc). Stimulating an animal's locus coeruleus, like stimulating its amygdala, produces anxiety behaviours.
1 A structure in the brain called the amygdala (uh-MIG-duh-luh) may play a role in controlling the fear response. People who have an overactive amygdala may have a heightened fear response, causing increased anxiety in social situations.  Environment. Social anxiety disorder may be a learned behavior. That is, you may develop the condition after witnessing the anxious behavior of others. In addition, there may be an association between social anxiety disorder and parents who are more controlling or protective of their children.