The histamine Ha-receptor was first characterized pharmacologically and reported'in 1983. It was shown to be located presynaptically on histaminergic neurones in the central nervous system (CNS), where it functions as an autoreceptor to modulate histamine release. The H3- receptor also modulates the synthesis of histamine from L-histidine. 2 Thus, activation of the Hs-receptor by histamine leads to a decrease in the concentration of the neurotransmitter ...
