What is Norepinephrine and What Does It Do?

It is known to many that the functioning of the human brain is based on the transmission of bioelectric signals. This transmission implies the presence of a series of elements that transmit information from one neuron to another, these elements being neurotransmitters. There are a large number of these substances of very different types, causing different reactions depending on their composition and place of reception. One of them is norepinephrine. It is a neurotransmitter and hormone that acts at multiple points in the human body. It is a catecholamine, a group of substances made up of norepinephrine, dopamine, and epinephrine, which come from tyrosine and which together with serotonin, acetylcholine, glutamate, glycine, opioids, anandamide, and GABA, are the principal neurotransmitters in the brain. This substance has a stimulating effect at the brain level, even when some of the receptors are inhibitors. It participates in both the transmission of messages between areas within the brain and with the outside, having great participation in the sympathetic nervous system. Likewise, norepinephrine does not only act as a neurotransmitter but also exerts functions in the endocrine system and is produced at both the brain and adrenal levels.

Its structure is very similar to that of epinephrine, with the only difference that the latter has a methyl group attached to its nitrogen. On the contrary, in norepinephrine, this methyl group is replaced by a hydrogen atom. The prefix “nor-” stands as an abbreviation of “normal,” as this compound is demethylated. It is synthesized from tyrosine; this amino acid experiences a series of transformations in postganglionic neurons and the adrenal medulla within the sympathetic nervous system.

Norepinephrine’s actions are vital to the fight or flight response, whereby the body prepares to react to or withdraw from an acute threat. Norepinephrine is similar to adrenaline. It widens the blood vessels, thus increasing the pressure and concentration of sugar in the blood. Norepinephrine is structurally classified as a catecholamine, containing a catechol group (a benzene ring with two hydroxyl groups) attached to an amine group (containing nitrogen). Compared to epinephrine, which is produced and stored primarily in the adrenal glands, norepinephrine is stored in small amounts in the adrenal tissue. Its primary storage and release zone are neurons of the sympathetic nervous system (a branch of the autonomic nervous system). Therefore, norepinephrine works primarily as a neurotransmitter with some function as a hormone that is released into the bloodstream from the adrenal glands.

The problem is that many times, we take everyday situations and problems related to them, thinking as if they really put our lives at risk. It is that permanent feeling of danger as if a car were about to hit us all day: this is chronic anxiety. The biggest problem with this is that the body reacts to that anxiety just as it would if we were in danger, making a huge revolution of hormones and neurotransmitters, including norepinephrine. The physical reactions that this entails can lead to other health problems, such as: 

• Headache
• Bad digestions
• Insomnia
• Loss of appetite
• Fatigue
• Sweating
• Constant feeling of general uneasiness

When norepinephrine suddenly shoots up, panic attacks or feelings of fear appear; because such a huge number of physical symptoms are triggered, they cannot explain them. Norepinephrine not only intervenes in cases of anxiety. It is also strongly related to other emotional imbalances, such as depression. Just as high levels of this neurotransmitter cause anxiety symptoms, very low levels put the body in a state of “hibernation.” You only react to survive and nothing more. Depression can be a cause or a consequence of low levels of norepinephrine. That is, depression can cause you to have low levels of the neurotransmitter, but it can also happen the other way around, where low levels cause depression. In any case, it is the absence of norepinephrine that causes many symptoms of depression, such as:

• Less physiological activation
• Diffuse attention or Attention difficulties
• Decreased heart rate
• Dysthymia
• Decreased motivation
• Increased motor reaction time
• Lack of energy
• Apathy (disinterest and lack of enthusiasm)

Eating a balanced diet, especially a diet rich in protein and Omega-3, is an excellent way to start taking care of your norepinephrine levels. It would also be best if you thought about doing activities that help regulate your hormones and neurotransmitters to avoid emotional imbalance. Doing yoga or meditation, for example, is a good idea to connect with the present moment and achieve a balance between the body and the mind. Doing other types of exercise is also good, although you should avoid those that generate too much stress (for example, being a goalkeeper for a soccer team). Taking walks and connecting with nature can also be an excellent way to help balance your hormones and your emotions.

Norepinephrine is also used clinically as a means of maintaining blood pressure in some types of disorders (e.g., septic shock or septicemia). It also is used in an emergency to treat hypotension, for example, during a surgical procedure. This drug is often used during CPR (cardiopulmonary resuscitation). The Swedish physiologist Ulf von Euler identified norepinephrine in the mid-1940s; He received a share of the 1970 Physiology or Medicine Nobel Prize for his discovery.