HCRT and narcolepsy: Loss of orexin (also known as hypocretin) (de Lecea et al. 1998; Sakurai et al. 1998) signaling results in narcolepsy and increased orexin signaling has been implicated in arousal, feeding and addiction (Horvath and Gao 2005; Baimel and Borgland 2017; James et al. 2017).