Dopamine is a neurotransmitter involved in several functions, such as experiencing pleasure and joy. In addition, dopamine is needed to make the hormones adrenaline and norepinephrine.
In total, eight brain circuits have been found to use dopamine. These circuits all perform a different function in the brain and from this it can be deduced that dopamine is involved in many different tasks. The most important circuits are the following five
The action of dopamine depends on the receptors it binds to. There are in fact five different receptors, all of which are located in a different place in the brain. As a result, they all have a different function. For example, D1 receptors are mainly found in the striatum and the neocortex, and these receptors are important for motor actions. However, D2 receptors are found in the striatum and limbic system, and are therefore important for emotional behavior.
The above functions already indicate a link between dopamine and the brain's reward system. When pleasant experiences occur, such as eating, drinking, having sex or taking drugs, dopamine is released into the brain. After such an experience, the brain is eager to get dopamine back, in order to get the nice feeling back as well. To satisfy this need, the same action is performed again, and potentially this can lead to the development of addictions.
It is common knowledge that various drugs and medications, such as cocaine for example, affect the action of dopamine. This is because they prevent the used dopamine from being easily reabsorbed to recycle it. This leaves a lot of dopamine active at the same time, causing overstimulation. As you could read above, overstimulation by dopamine creates a nice feeling (it's like candy for the brain). The brain gets used to the high concentrations of dopamine, and next time even more dopamine is needed to give the same feeling.
Author: Myrthe Princen (translated by Joyce Burger)