“…H 3 receptormediated inhibition of histamine release has also been observed in human cerebral cortex (Arrang et al, 1988b). Differences in the distribution of H 3 receptor binding sites and the levels of histidine decarboxylase (an index of histaminergic nerve terminals) suggested at an early stage that H 3 receptors were not confined to histamine-containing neurons within the mammalian CNS (Arrang et al, 1987a;van der Werf and Timmerman, 1989). This has been confirmed by the observations that H 3 receptors can regulate serotonergic (Schlicker et al, 1988(Schlicker et al, , 1989Threlfell et al, 2004), noradrenergic (Schlicker et al, 1989), cholinergic (Clapham and Kilpatrick, 1992), and dopaminergic (Schlicker et al, , 1993Munari et al, 2013) neurotransmitter release in mammalian brain.…”