Norepinephrine is also released from postganglionic neurons of the sympathetic nervous system, to transmit the fight-or-flight response in each tissue respectively. The adrenal medulla can also be counted to such postganglionic nerve cells, although they release norepinephrine into the blood.
By indication
Norepinephrine may be used for the indications attention-deficit/hyperactivity disorder, depression and hypotension. Norepinephrine , as with other catecholamines, itself cannot cross the blood-brain barrier , so drugs such as amphetamines are necessary to increase brain levels.
Attention-deficit/hyperactivity disorder
Norepinephrine, along with dopamine, has come to be recognized as playing a large role in attention and focus.