A neurotransmitter involved in mood management and associated with happiness. Often called the "happy hormone", serotonin activates or inhibits brain activity depending on the receptor to which it binds. Serotonin is essential for neurons to communicate with each other.
Serotonin (or 5-HT) is a neurotransmitter synthesised from tryptophan, an amino acid found in food (tryptophan is found in whole-grain rice, dairy products, eggs, meat and fish, nuts, etc.). 95% of serotonin is produced in the intestine, and only 5% in the brain by certain so-called serotonergic neurons.
The happiness hormone
Serotonin regulates mood, sleep/wake patterns, appetite, pain perception, body temperature, libido and alertness.
The effect of serotonin on emotions is indisputable and can be explained by the presence of its receptors in the limbic system (the emotional brain) in general and the amygdala in particular, brain structures that are very involved in the response to fear and anxiety.
Serotonin binds to at least 15 different types of receptor, both inhibitory and excitatory. This neurotransmitter regulates the activity of neurons, usually by reducing it either directly or via inhibitory interneurons.
For example, in the striatum (a structure involved in involuntary movement, food or sexual motivation, pain and wound healing), serotonergic neurons inhibit the neurons that secrete dopamine.
Serotonin also inhibits numerous regions of the brain. If serotonin levels are too low, these regions become uninhibited, which can lead to impulsive and/or aggressive behaviour. This is why certain antidepressants known as pro-serotoninergics use this property, slowing down the capture of serotonin so that it remains available.
The involvement of serotonin has also been confirmed in other psychological disorders, such as anxiety and personality disorders.
The blocking or activation of serotonin receptors is also the basis of anti-migraine drugs and anti-emetics used to treat vomiting and nausea.Warning: if you overdose on certain drugs that stimulate serotonin receptors too much, you may develop serotonin syndrome.In this case, severe anxiety, delirium with confusion, tremors, muscle spasms, rapid heart rate, high blood pressure, high body temperature, sweating, shivering and/or vomiting may occur.
- Dopamine :
- Nicknamed the "pleasure molecule", dopamine is a chemical messenger that allows information to flow between certain types of neuron.