[The histamine H(3) receptor: a target for new drugs].

The histamine H3 receptor has been identified in the rat brain as a presynaptic autoreceptor inhibiting histamine synthesis and release. Following its recent cloning, more than fifteen years later, the existence of isoforms, species pharmacological differences and the high constitutive activity of the receptor were established. All these molecular findings have to be taken into account for the optimization of the ligands aiming at a clinical use. They show the interest of antagonists/inverse agonists in the symptomatic treatment of schizophrenia and cognitive and attentional deficits.