Norepinephrine-mediated emotional arousal facilitates subsequent pattern separation

► Pattern separation is ascribed to the hippocampal dentate gyrus. ► The dentate is subject to norepinephrine modulatory control. ► We raised endogenous noradrenergic activity by using fearful stimuli. ► Noradrenergic activity was associated with enhanced pattern separation. ► Relationship persists after controlling for general memory enhancement.