Histamine Receptor H3 (HRH3)

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.