Modeling the role of mid-wavelength cones in circadian responses to light.
Nonvisual responses to light, such as photic entrainment of the circadian clock, involve intrinsically light-sensitive melanopsin-expressing ganglion cells as well as rod and cone photoreceptors. However, previous studies have been unable to demonstrate a specific contribution of cones in the photic control of circadian responses to light. Using a mouse model that specifically lacks mid-wavelength (MW) cones we show that these photoreceptors play a significant role in light entrainment and in phase shifting of the circadian oscillator. The contribution of MW cones is mainly observed for light exposures of short duration and toward the longer wavelength region of the spectrum, consistent with the known properties of this opsin. Modeling the contributions of the various photoreceptors stresses the importance of considering the particular spectral, temporal, and irradiance response domains of the photopigments when assessing their role and contribution in circadian responses to light.
Dkhissi-Benyahya
Ouria
O
INSERM, U846, Stem Cell and Brain Research Institute, Department of Chronobiology, F-69500, Bron, France.
Gronfier
Claude
C
De Vanssay
Wena
W
Flamant
Frederic
F
Cooper
Howard M
HM
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology* / Q000528:radiation effects; D015870:Gene Expression / Q000502:physiology; D008027:Light; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D009043:Motor Activity; D017440:Photoperiod; D017949:Retinal Cone Photoreceptor Cells / Q000002:abnormalities* / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D017299:Rod Opsins / Q000235:genetics / Q000502:physiology*; D037042:Thyroid Hormone Receptors beta / Q000235:genetics; D000099210:Melanopsin
D017299:Rod Opsins; D037042:Thyroid Hormone Receptors beta; D000099210:Melanopsin