Ultraviolet Light Provides a Major Input to Non-Image-Forming Light Detection in Mice

Abstract

SummaryThe 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.

A visual circuit uses complementary mechanisms to support transient and sustained pupil constriction

“…These results are surprising given previous proposals that cones are important for transient ipRGC responses, including acute changes in pupil size (Allen et al, 2011; Dkhissi-Benyahya et al, 2007; Gooley et al, 2012, 2010; Ho Mien et al, 2014; Kimura and Young, 2010, 1999; Lall et al, 2010; Spitschan et al, 2014; van Oosterhout et al, 2012). Therefore, we sought to acutely modulate cone activity using a previously characterized mouse line that expresses the human ‘red’ opsin ( OPN1LW ) in place of the mouse ‘green’ opsin ( Opn1mw ) (Red cone KI), making cones the only photoreceptors with enhanced sensitivity to red light (Lall et al, 2010) (Figure 2C).…”

Masking of a circadian behavior in larval zebrafish involves the thalamo-habenula pathway

“…In rodents, UV-sensitive cones contribute to non-image forming response such as circadian photoentrainment and light-induced phase shift 21 . We thus tested whether UV light is able to mask vertical migration of larval zebrafish.…”

Cardiac Period 2 in myocardial ischemia: Clinical implications of a light dependent protein

“…As light receptors in the retinal ganglion cells are most sensitive to blue light (Hattar et al, 2002), newer light boxes mainly emit blue light to shorten exposure times. Surprisingly, a very recent study using UV light showed that ultra-violet sensitive cones might also play an important role for circadian and sleep regulation in mice (van Oosterhout et al, 2012). However, exploring whether UV light is a safe approach in the context of resetting the circadian clock would require further evaluation.…”