Histamine H3-receptor isoforms

Increasing evidence supports a role for HA as a neurotransmitter and neuromodulator in various brain functions, including emotion, cognition, and feeding. The recent cloning of the histamine H-3 receptor allowed for the subsequent cloning of a variety of H-3 receptor isoforms from different species as well as the H-4 receptor. As a result a wide variety of H-3-receptor isoforms are now known that display differential brain expression patterns and signalling properties. These recent discoveries are discussed in view of the growing interest of the H-3 receptor as a target for the development of potential therapeutics.