Brain reward system: neurobiology of motivation

Although the brain’s reward system is often talked about as the mechanism that orchestrates addictions, there is an essential aspect that we must understand. Having goals in life is synonymous with health and well-being. Thus, all that neurobiology, which is behind the motivation and pleasure that we find in our daily lives, is regulated by this same very complex and fascinating circuit.

Eating, resting, a conversation with friends in a cafewait a like in the photo that we have just uploaded to our social networks, eating a dessert filled with chocolate, leaving work before work to go shopping or to the movies… All these very basic behaviors that accompany us in each of our days are governed by the system brain reward.

Often, when we talk about this system, it is common to hear that its most basic priority is to guarantee our survival. All the processes orchestrated by this primordial instinct are automatic. and governed, in most cases, by a basic emotion: fear. Through it we are cautious and remember that life has dangers and that it is often worth staying in our comfort zone.

Now what about pleasure? What purpose do all those positive behaviors mentioned above have? Believe it or not, The motivation and well-being that we find carrying out certain behaviors is also part of our evolution.

Sometimes, people are surrounded by multiple stimuli and diverse situations. In these contexts it is necessary to prioritize the good, what at a given moment will be beneficial to oneself.

For example, our brain will reward us when, after a day of stress and work, we choose to meet that special friend for a drink and relax. He will also give us dopamine when, in the middle of a hot morning, we go in search of a glass of water to hydrate ourselves.

Therefore, the purpose of this brain circuit is ensure that we are motivated towards concrete and specific behaviors that he considers appropriate.

What is and where is the brain’s reward system?

When we talk about the brain’s reward system we are referring to a series of structures that are activated when rewarding or reinforcing stimuli are detected.

For example, when we see a freshly made pizza, an ice cream, that book whose publication we were waiting for or any other stimulus that fits our tastes and needs at that moment, the brain responds by releasing a very specific neurotransmitter: dopamine. That is when the motivation to achieve that goal is triggered.

It was in the 50s when the existence of this mechanism was discovered. In that decade, neurologists James Olds and Peter discovered that by stimulating certain brain areas, mammals experienced greater motivation to obtain something.

That discovery represented a revolution, to the point of thinking that by applying electrodes to various areas of the brain, human behavior could be changed.

So much so that in 1972 a very controversial experiment was carried out that sought to modify the behavior of a young homosexual. The data and conclusions were published in Journal of behavioral therapy and experimental psychiatry.

On the other hand, and as a result of all those more or less ethical experiments and tests, something that could be achieved is to understand what structures were involved in the brain’s reward system. They are the ones we present to you below.

Mesolimbic dopaminergic pathway

It is the main pathway through which dopamine is released and flows. It begins in the ventral tegmental area and connects in turn with relevant structures such as the nucleus accumbens, the amygdala, the hippocampus and the prefrontal cortex. This structure is related to pleasure and rewarding experiences.

The ventral tegmental area

More than a structure, it is actually a group of neurons (dopaminergic cells) located in the midbrain. This area is related to processes as basic as intense emotions, within which we find love, learning, motivation, orgasms and addictive behaviors.

Nucleus accumbens

In this case we have another type of accumulation of neurons, which are involved in processes such as pleasure, laughter, motivation, fear, aggression, addiction, among others.

Cerebral cortex

It is the outermost layer of the brain, the most sophisticated and where most of our executive functions or cognitive processes are regulated. This area is also related to the reward system. However, it is worth remembering that None of these structures work in isolation, All of them are interconnected with each other by a structure called the limbic motor reinforcing circuit.

This mechanism combines motivational and emotional areas with motor functions.those that encourage us to mobilize and even plan behaviors and plans thanks to the cerebral cortex.

The addictive processes

We pointed it out at the beginning. Every time the brain’s reward system is talked about, it is common to relate it to addictive behaviors. Now that we know that this circuit is involved in many more processes and behaviors than the most common, it is time to understand Why are there people who end up in these types of states characterized by addiction?.

It is known that there are multiple factors: social, family and even psychological. However, it is striking to know that There are certain genetic components capable of making certain people more susceptible than others. This in itself is revealing, since as explained in a study published by Clinical pharmacology and therapeutics, it facilitates treatment in many cases.

For example, It is known that certain alterations in the mesolimbic reward system facilitate addictive behavior. However, beyond the triggers and causes, there is a fact that we cannot ignore. We know that the brain gratifies us or pushes us to achieve certain things that it considers positive.

If so, why do addictive behaviors continue if they are harmful? Well, what actually happens is that certain harmful substances, like any type of drug, What they do is completely “alter” the reward system.

This transforms and modifies in such a way that control is lost, until it impacts almost any area of ​​our brain. The person lives for a single objective: to obtain that substance or repeat that behavior compulsively.

Our reality changes completely, as does our behavior, personality and, of course, health. Therefore, understanding how the brain’s reward system works allows us to understand much more about human beings. As we could see, It is a mechanism that regulates much of our behaviorwhether positive or negative.

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