title: Ultraviolet light provides a major input to non-image-forming light detection in mice.
abstract: The change in irradiance at dawn and dusk provides the primary cue for the entrainment of the mammalian circadian pacemaker. Irradiance detection has been ascribed largely to melanopsin-based phototransduction [1-5]. Here we examine the role of ultraviolet-sensitive (UVS) cones in the modulation of circadian behavior, sleep, and suprachiasmatic nucleus (SCN) electrical activity. UV light exposure leads to phase-shifting responses comparable to those of white light. Moreover, UV light exposure induces sleep in wild-type and melanopsin-deficient (Opn4(-/-)) mice with equal efficacy. Electrical recordings from the SCN of wild-type mice show that UV light elicits irradiance-dependent sustained responses that are similar to those induced by white light, with characteristic fast transient components occurring at the light transitions. These responses are retained in Opn4(-/-) mice and preserved under saturating photopic conditions. The sensitivity of phase-shifting responses to UV light is unaffected by the loss of rods but is severely attenuated by the additional loss of cones. Our data show that UVS cones play an important role in circadian and sleep regulation in mice.
authors: Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
authors: Floor
authors: F
authors: van Oosterhout
authors: Simon P
authors: SP
authors: Fisher
authors: Hester C
authors: HC
authors: van Diepen
authors: Thomas S
authors: TS
authors: Watson
authors: Thijs
authors: T
authors: Houben
authors: Henk Tjebbe
authors: HT
authors: VanderLeest
authors: Stewart
authors: S
authors: Thompson
authors: Stuart N
authors: SN
authors: Peirson
authors: Russell G
authors: RG
authors: Foster
authors: Johanna H
authors: JH
authors: Meijer
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D017299:Rod Opsins / Q000502:physiology*; D012890:Sleep / Q000528:radiation effects; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D014466:Ultraviolet Rays; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin