Summary
This study tested whether melanopsin-based photoreception mediates light-induced changes in voluntary alcohol intake in mice, finding that melanopsin knockout mice showed the same reductions in ethanol intake under constant light and constant darkness as wild-type controls. For lighting design, this suggests that light-driven behavioral changes (such as seasonal variation in substance use) may operate through non-melanopsin photoreceptive pathways, complicating simple melanopsin-targeted interventions.
Key Findings
- Opn4-/- (melanopsin knockout) mice showed expected reductions in circadian light sensitivity compared to wild-type controls, confirming the knockout's effectiveness.
- Both Opn4-/- and wild-type mice displayed identical reductions in voluntary ethanol intake under constant light (LL) and constant darkness (DD) conditions, indicating melanopsin signaling is not necessary for light-induced changes in alcohol preference.
- The study used a 3-week LD 12:12 baseline, followed by 3 weeks of LL or DD, then 3 weeks of return to LD 12:12, with continuous access to 10% ethanol solution.
Categories
The Science of Light: Investigates the role of melanopsin/ipRGC signaling in mediating photoperiod effects on behavior, using Opn4 knockout mice to dissect melanopsin-specific contributions to light-driven physiological changes.
Sleep & Circadian Health: Examines how constant light and constant darkness conditions affect circadian entrainment and related behavioral outputs, including the role of the SCN pacemaker and retinohypothalamic tract.
Author(s)
R Brooks
Publication Year
2019
Related Publications
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice
Sleep & Circadian Health
- Phototransduction by retinal ganglion cells that set the circadian clock
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- The twoâprocess model of sleep regulation: a reappraisal
- Melanopsin is required for non-image-forming photic responses in blind mice
- Strange vision: ganglion cells as circadian photoreceptors