The majority of the noradrenergic neurons are located in the locus ceruleus in the dorsal pons. Other areas of the brain that contain noradrenergic neurons include the limbic system (hypothalamus, hippocampus, and amygdala) as well as the cerebral cortex [14]. Autonomic arousal occurs with stimulation of the locus ceruleus, and the elevated norepinephrine levels are associated with somatic anxiety symptoms such as a rapid heart rate and increased blood pressure [4]. Chronic symptoms of increased noradrenergic function in patients with anxiety disorders include startle response, insomnia, and panic attacks [14]. Anxiety is associated with an increase in the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). There is a high concentration of GABA (inhibitory neurotransmitter) receptors on the noradrenergic cell bodies in the locus ceruleus [4].