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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 These types of learned associations happen every day, and can cause you to feel fear without necessarily knowing why.  On-Edge Feeling Whether or not anxiety directly creates that feeling of being afraid and on edge isn't clear. But there is some evidence that your mind adapts to the way you feel. So when you have anxiety, and your body starts reacting like you're experiencing a fear response, then your mind may also adapt to that feeling and start to feel fearful as a result of your anxiety symptoms.