What Is the Function of Norepinephrine?

Norepinephrine, a chemical produced by the brain, is a neurotransmitter secreted by nerve endings and a hormone secreted by the adrenal medulla. It has assured man's survival on this planet while having the ability to inflict him with psychological and physiological torment.

Neurotransmitter

• As a neurotransmitter, norepinephrine has a role in alertness, emotions, sleeping, dreaming and learning, as noted on the website "The Brain From Top To Bottom," presented by McGill University in Canada.

Hormone

• The World of Molecules cites the role of the hormone norepinephrine during stressful situations. Along with epinephrine, it increases heart rate and blood flow to the heart, brain and muscles, and prepares the body for the fight-or-flight response.

Significance

• On the positive side, the stress-induced chemical reaction motivating the fight-or-flight response has enabled the survival or the human race. On the negative side, this chemical reaction interferes with weight loss and contributes to obesity by preserving fat stores as a source of fuel for energy, according to Shari Lieberman, PhD, in her article "How Stress Can Make Us Gain Weight."

Malfunction

• The effects of malfunctioning norepinephrine secretion, as described by Mental Health Matters, can include development of phobias, hostility, attention-deficit/hyperactivity disorder (ADHD), panic attacks and bipolar disorder.

Emergency Use

• On its website, the University of Maryland Medical Center indicates norepinephrine is one of the medications used to treat severe cases of hypotension (low blood pressure) resulting from trauma, septic shock or heart disease.