5-HT7 receptor

The 5-HT₇ receptor is a member of the GPCR superfamily of cell surface receptors and is activated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) The 5-HT₇ receptor is coupled to G_s (stimulates the production of the intracellular signaling molecule cAMP) and is expressed in a variety of human tissues, particularly in the brain, the gastrointestinal tract, and in various blood vessels. This receptor has been a drug development target for the treatment of several clinical disorders. The 5-HT₇ receptor is encoded by the HTR7 gene, which in humans is transcribed into 3 different splice variants.

Function

When the 5-HT₇ receptor is activated by serotonin, it sets off a cascade of events starting with release of the stimulatory G protein G_s from the GPCR complex. G_s in turn activates adenylate cyclase which increases intracellular levels of the second messenger cAMP.

The 5-HT₇ receptor plays a role in smooth muscle relaxation within the vasculature and in the gastrointestinal tract. The highest 5-HT₇ receptor densities are in the thalamus and hypothalamus, and it is present at higher densities also in the hippocampus and cortex. The 5-HT₇ receptor is involved in thermoregulation, circadian rhythm, learning and memory, and sleep. It is also speculated that this receptor may be involved in mood regulation, suggesting that it may be a useful target in the treatment of depression.