Catecholamines. These are both catecholamines, synthesized from the Amino Acid tyrosine. Norepinephrine (ne) acts mainly in an area of your brainstem called the locus coeruleus -- triggering the stress response. Ne is also involved in pain, cognition, mood, emotions, movement and blood pressure. Dopamine is involved in regulating mood, pleasure, delusions, psychosis and drug abuse -- and more.