Serotonin (or 5-HT) receptors are possibly of special importance in the development and triggering of migraine attacks. Already in 1957, the scientists Gaddum and Picarelli described two types of serotonin receptors. It became clear very soon, that serotonin receptors existed in the blood vessels of the head, which were reacting atypically.
Therefore, Bradly and his collegues divided the serotonin receptors into 3 main groups in 1986: 5-HT1 receptors (consisting of more subtypes), 5-HT2 receptor and 5-HT3 receptor.
The scientist Dumuis and his colleagues described a separate 5-HT4 receptor in 1989. One should not let oneself be confused by these labels. They are nothing else but substitutes for postcodes or ZIP codes of the organism. Serotonin, by activating these receptors, is able to end migraine headaches. However because it acts on all receptor subtypes in many parts of the whole organism, serious side effects result which make it useless as a migraine medication.
Serotonin can be compared to bulk mailing every household. It causes undesirable constriction of the blood vessels outside the head by activating 5-HT2 receptors. This effect can impair the blood circulation of the coronary vessels in the heart. The effect on the blood vessels of the head are caused by activating the 5-HT1 receptors. It was shown that other receptors are not involved in the constriction of the vessels of the head. With the so-called selective 5-HT1 antagonists it was possible for the first time to enable a targeted selective blockade of the neurogenic inflammation of the vessels of the brain circulation. These are called triptans.