In other studies, antagonists of H3R have demonstrated pro-attentional effects in various ADHD-specific animal models including five-trial inhibitory avoidance in SHR pups (thioperamide, ABT-239, GT-2331, and ciproxifan) (Fox et al., 2002; Komater et al., 2003) and impairment in a 5-CSRTT (ciproxifan) (Day et al., 2007). Here, HRH3 is linked to attention deficit-hyperactivity disorder.