HCRT and Cataplexy: Interestingly, a blockade of both orexin (OX1 and OX2) receptors by selective antagonists that was identified as a common molecular mechanism across mammalian species, identified in mice, rats, dogs, and humans, was found to promote sleep and increase both REM and non-REM sleep [62], even without inducing the lack of orexin signaling associated with cataplexy [63].