Pupil Size Coupling to Cortical States Protects the Stability of Deep Sleep via Parasympathetic Modulation (Current Biology)

Using infrared back-illumination pupillometry in head-fixed sleeping mice, Yüzgeç et al. show that pupil diameter is tightly coupled to cortical states during sleep. Pharmacological and light-stimulation experiments reveal that the pupillary constrictions are parasympathetically driven and might have a protective function to stabilize deep sleep.