Anandamide: the effects of this neurotransmitter on the brain

It is a substance secreted by neurons, and is involved in many Biological processes.

Serotonin, dopamine, noradrenaline, glutamate? are some of the best known and most popular neurotransmitters in the among those that travel through the nervous system of our organism, allowing neurons to communicate with each other. But they are not the only ones.

And there are a large number of substances that are not so often talked about and yet play an important role in our daily lives. One of them is anandamideof which we are going to speak throughout this article.

Anandamide: what is this substance?

Anandamide, also known as arachidonoylethanolamide or AEA, is one of the many chemical compounds that our body uses to produce neurotransmitters. one of the many chemical compounds that our body manufactures. endogenously. It is an endogenous lipid with a high affinity for cannabinoid receptors. In fact, it is considered one of the best known eicosanoid endocannabinoids (fatty acid derivatives) and the second most abundant. Discovered in 1992, the name of this lipid derives from the Sanskrit word for happiness or bringer of peace, "ananda", due to the effects and relaxation it generates, and is composed of arachidonic acid and ethanolamine.

Short-lived and easy to degrade, anandamide is a fragile molecule whose effects are short-lived in the human body.. This substance is linked, like the other cannabinoids, to sedation, to the reduction of vomiting and hunger provocation, to an improvement of the respiratory function and to relaxation, as well as to some problems of concentration, time perception and even memory.

It is a substance that is not produced in a particular region of the brain, but is secreted by the membrane of neurons. secreted by the membrane of neurons, and has been localized in different regions of the organism, both inside and outside the brain.It has been localized in different regions of the organism, both inside and outside the brain. It is commonly found in the thalamus, hippocampus, basal ganglia and cerebellum, as well as in the spleen and heart. Its receptors are therefore widely distributed, being linked to the G protein.

On the other hand, anandamide can also be acquired through the consumption of different foods.. Some of its best known natural sources are cocoa and chocolate, anandamide being in fact one of the main elements that make it seem so pleasant to most people. It is also present in some fish and their roe, or in sea urchins.

Synthesis and uptake of anandamide

Anandamide is an endocannabinoid that originates in the membrane of neurons from the hydrolysis of its precursor, a phospholipid called N-arachidonoyl phosphatidylethanolamine (or NAPE) derived from the membrane's own arquedonic acid. This synthesis occurs thanks to the enzyme phospholipase Dand ethanolamine also binds to form anandamide. Anandamide is characterized by the fact that it is generated only at the moment it is going to be released, unlike other neurotransmitters which are previously manufactured and stored until the moment of its transmission. It is usually generated by the postsynaptic neuron, in a retrograde manner, generating a stimulation or inhibition of the production of neurotransmitters in the presynaptic.

At that moment, this substance is released into the synaptic space, to be subsequently received by both neurons and glial cells. Once taken up, it is degraded to ethanolamine and arachidonic acid and then reincorporated into membrane lipids. This substance is then rapidly metabolized by the body, disappearing in a short period of time.

Functions of anandamide

Anandamide is a very useful substance for our organism, which has important roles in our brain and body function. While many of them have already been mentioned above, let's look at them in more depth. Among the many functions or roles of anandamide, the following stand out.

1. Homeostasis

As part of the endocannabinoid systemsystem, anandamide plays an important role in maintaining body homeostasis, influencing and modulating nerve transmission and interacting with multiple systems and neurotransmitters. Among others, it can inhibit GABA and glutamate synthesis. It also participates in lowering ocular pressure.

2. Modulates pain

As with the rest of cannabinoids, one of the main and most recognized functions of cannabinoids is to modulate and generate a decrease in the sensation of pain in the event of an injury, having an analgesic effect.having an analgesic effect.

3. They prevent cell proliferation

Another of the actions that anandamide performs, and that in fact nowadays is still being investigated and generating a great interest, is the fact that its action prevents or decreases the cellular proliferation of cancerous cells, causing the death of these cells. This has been especially investigated in melanomas..

4. It has a neuroprotective effect

Cannabinoids also have a neuroprotective effect as they have the capacity to decrease the excitation of the nervous system, which in turn has a protective effect on the excitotoxicity of the nervous system. has protective effects against excitotoxicity..

5. Stimulates hunger

Anandamide and the endocannabinoids as a whole alter and modulate feeding, being in close interaction with leptin. While the latter is one of the main hormones that regulates satiety, anandamide stimulates appetite and generates food seeking. Anandamide would generate an effect in the form of loss or decrease of appetite.. If there is an increase in leptin, this generates a reduction of anandamide levels in the hypothalamus.

6. It has an antiemetic effect

As with cannabis, anandamide has an antiemetic effect. That is, it inhibits vomiting by interacting with serotonin.

7. Modulates sexual behavior

One of the interactions that anandamide has is with sex hormones. with sex hormones. Apparently, in this sense anandamide has a biphasic response: small amounts stimulate sexual activity, while high doses inhibit it.

8. Influences on pregnancy

Some studies associate a very relevant role to anandamide in generating the implantation of the embryo in the epithelium of the uterus. implantation of the embryo in the epithelium of the uterus..

9. Involved in motivation

In experiments with mice, it was observed that anandamide apparently contributes to motivation and decision making, accelerating it and generating a greater capacity for action and reaction in the search for solutions.

10. A role in learning and memory

The functioning of anandamide in the brain has also been found to be related to learning and memory related to the capacity of learning and memoryIt is frequently found associated with the areas that manage memory, such as the hippocampus. In principle, it facilitates the creation of new brain connections and the elimination of old ones. However, some animal models seem to indicate that it can generate memory problems.

11. Link with feelings of relaxation and happiness.

The name of this substance, as we said at the beginning of the article, is linked to the idea of peace, relaxation and happiness. It is associated with pleasure. It also generates a distortion of temporal perception.

Bibliographical references

• Escobar, I.E.; Berrouet, M.C. and González, D.M. (2009). Molecular mechanisms of marijuana addiction. Revista Colombiana de Psiquiatría, 38 (1).
• Spanish Society for Cannabinoid Research (2002). Basic Guide on Cannabinoids. Ministry of the Interior. Spain.
• Zona, L.C.; Fry, B.R.; LaLonde, J.A. & Cromw, H.C (2017). Effects of anandamide administration on components of reward processing during free choice. Pharmacology Biochemistry and Behavior, 158: 14-21.