HRH3 and Anxiety: Augmented histamine transmission, leading to activation of postsynaptic histamine H1 receptors, has been proposed to exert anxiogenic effects.60, 61 In contrast with this possibility, Bahi et al. reported that administration of an H3R antagonist, which promotes histamine release, counteracts anxiety in naive mice.62 In the present study, thioperamide did not affect the anxious phenotype produced by partial dopamine depletion.