Histamine Receptor H3 (HRH3)

Histamine H3 receptors are expressed in the central nervous system and to a lesser extent the peripheral nervous system, where they act as autoreceptors in presynaptic histaminergic neurons, and also control histamine turnover by feedback inhibition of histamine synthesis and release. The H3 receptor has also been shown to presynaptically inhibit the release of a number of other neurotransmitters including, but probably not limited to dopamine, GABA, acetylcholine, noradrenaline, and serotonin.The gene sequence for H3 receptors expresses only about 22% and 20% homology with both H1 and H2 receptors respectively.H3 receptors are thought to play a part in the control of satiety.The diverse expression of H3 receptors throughout the cortex and subcortex indicates its ability to modulate the release of a large number of neurotransmitters.