5-HT1 receptor

In the field of neurochemistry, 5-HT1 receptors are a subfamily of 5-HT receptors which bind the neurotransmitter and peripheral signal mediator serotonin, also known as 5-hydroxytryptamine (5-HT).

Mode of action
5-HT1 receptors are G protein coupled receptors that Gi/Go-coupled. This causes a cellular decrease of cAMP.

Subtypes
Although working basically through the same mechanism, there are several 5-HT1 receptor subtypes (denoted A-F), each encoded by a separate gene. Furthermore each subtype has a somewhat different tissue distribution and binding preference for synthetic 5-HT1 agonist and antagonist ligands.

5-HT1A
5-HT1A acts on the CNS, where it induces neuronal inhibition and controls behaviour, such as sleep, feeding, thermoregulation, aggression, anxiety.

5-HT1B
5-HT1B acts on the CNS, where it induces presynaptic inhibition and behavioural effects. It also has vascular effects, such as pulmonary vasoconstriction.

5-HT1D
5-HT1D acts on the CNS, and affects locomotion and anxiety. It also induces vascular vasoconstriction in the brain. Ergotamine works primarily through the 5-HT1B receptor, since the effect through the 5-HT1D receptor is contrary to the mode of action of ergotamine, i.e. vasoconstriction.