The Dual Orexin Receptor Antagonist DORA-22 Improves Mild Stress-induced Sleep Disruption During the Natural Sleep Phase of Nocturnal Rats

•Evaluation of hypnotic dual orexin receptor antagonists (DORAs) during the rodent inactive period may prove translationally significant.•DORA-22 improved sleep measures when animals were exposed to mild stress-inducing stimuli (cage exposures) in the light/inactive period.•A minimal dose of DORA-22 initially promoted sleep yet exhibited few lingering (extended) effects.•DORA treatment of sleep pathologies may alleviate alterations during the natural sleep period, while avoiding lingering hypersomnolence.