HRH3 and Cognitive impairment: Selective H3R antagonists have been shown to improve performance in a diverse range of rodent cognition paradigms, including object recognition, olfactory recognition, water maze, radial maze, and passive avoidance, with most pronounced effects being observed in models where a cognitive deficit is present such as in aged animals (Hancock and Fox 2004; Witkin and Nelson 2004; Medhurst et al.