The H3 receptor agonist exhibits all of the following actions except
H3 receptors act as presynaptic receptors and decrease the release of histamine and other neurotransmitters. this antagonize H1 mediated wakefulness and bronchoconstriction. these also decrease gastrin release and produced negative chronotropic effect inverse agonist and H3 receptor(tiprolisant) is proved for narcolepsy. Refer KDT 6/e p153