What is norepinephrine and what is its function?

What is norepinephrine?

Noradrenaline or norepinephrine belongs to the group of catecholamines (1) that can act as a neurotransmitter and as a hormone with multiple physiological and homeostatic functions in the body, which  is synthesized in the adrenal medulla where it is released into the bloodstream through the noradrenergic neuronal cells. (two)

In this sense, norepinephrine and adrenaline have the primary function of putting our body on alert , according to the so-called fight or flight reaction, and their action is mainly on adrenergic receptors.

Note: Norepinephrine is a chemical derived from dopamine , which is part of the ” happiness hormones ” and is present in both the Central Nervous System (CNS) and the peripheral. (3)

It should be noted that norepinephrine is also synthesized in pharmaceutical laboratories and is administered parenterally in continuous perfusion to prevent tissue necrosis, for example, and with a fairly safe profile. (4)

What is the function of norepinephrine?

Norepinephrine has various functions within the metabolism and functioning of the organism, of which we describe the most important:

1. Increases attention span and memory

This hormone is related to the functioning of some cognition processes, such as memory and attention.

Similarly, norepinephrine is activated in the presence of chronic stress, such as panic states caused by the presence of imminent dangers, increasing the ability to memorize this type of event.

On the other hand, norepinephrine is involved in cerebral attention , causing excitatory activation in the cortex of the brain , which facilitates vigilance and alertness to the environment that surrounds us.

Important: Norepinephrine and adrenaline, together with dopamine, serotonin, acetylcholine , glutamate and glycine , are part of the main brain neurotransmitters.

2. Regulates the survival response to danger

Norepinephrine, once released due to a state of danger, regulates motor and cognitive responses intended to maintain the survival of the species, such as escape or fight.

This neurotransmitter speeds up communications between neurons, which allows the body’s action response to be carried out almost immediately in states of emergency.

To highlight: Because norepinephrine behaves primarily as a neurotransmitter , its main function is the transmission of signals between neurons.

3. Increases heart rate and blood flow

Due to its excitatory effect, this hormone is capable of increasing the heart rate in stressful situations and with it the blood flow to the different organs.

In this sense, norepinephrine acts by increasing heart rate and vascular tone, producing an increase in blood pressure, thus increasing the amount of blood that is used by the body to ensure a rapid response. 

You should know: Low levels of norepinephrine in the body can cause hypotension and when injected can cause cardiac arrhythmias.

4. Regulates stress levels and mood

Other information about noradrenaline is that it also appears in states of anxiety and imminent danger, preparing the body to generate an immediate response if necessary. If this hormone is maintained in the bloodstream, surely the state of stress will remain.

Likewise, science has reported that depressive states in individuals have been related to a decrease in the presence of norepinephrine in the blood, as in cases of major depression . (5)

Note: Catecholamines, such as norepinephrine, are stored as a complex with ATP ( adenosine triphosphate ), to be released in response to a stimulus .

5. Control sexual desire

This catecholamine is involved in the regulation of sexual appetite , since it is responsible for promoting physical and emotional changes that lead to increased (or reduced) sexual desire.

Important: Let’s remember that norepinephrine is a chemical compound that comes from dopamine , a hormone related to sexual desire.

6. Maintains the state of wakefulness

Norepinephrine helps us maintain proper functioning, the state of wakefulness and the level of consciousness during the day.

In this sense, when it flows at adequate levels through our body , it prevents sleep from entering during the day , but if there is a mismatch in the levels (decrease) of this hormone in the blood, it is possible that there are difficulties in maintaining attention . .

To highlight: The physiological stimulus for the release of norepinephrine is caused by the neurotransmitter acetylcholine .

Key Findings

• Norepinephrine is primarily a brain neurotransmitter, but it is also considered a hormone.
• This chemical compound is activated in situations of danger or chronic stress.
•  Norepinephrine works to place our body on alert and generate an immediate response.
• This hormone is synthesized in the adrenal medulla and released by the action of acetylcholine.