HRH3 and sleep disorder: The compound pitolisant, a histamine H3 receptor antagonist, has recently been approved for use in humans to treat sleep disorders, specifically narcolepsy (Wakix®, (Fabara, Ortiz et al. 2021, Sarfraz, Okuampa et al. 2022)) and has been shown to exhibit efficacy in fear memory in wild-type mice (Brabant, Charlier et al. 2013).