Summary
This study demonstrates that the morning circadian oscillator is more photosensitive than the evening oscillator and responds differently to the tempo of light delivery, even when total light exposure is held constant. These findings suggest that optimized intermittent light protocols — rather than continuous exposure — could more efficiently advance circadian phase in the morning, with potential applications for shift work, jet lag, and dawn-simulation lighting systems.
Key Findings
- Phase advances in activity onset depended on the tempo (pattern) of light administration, not just total photon exposure, across a 15-minute window at ZT23 (1 hour before dawn).
- The morning oscillator at ZT23 was more photosensitive than the evening oscillator at ZT13, benefiting from a greater number of light fractionation strategies.
- Pulse train protocols that optimized evening oscillator delay resetting at ZT13 were equally effective for morning oscillator advance resetting at ZT23.
- Data were collected from over 1,300 Drosophila across 19 separate pulse train protocols, providing robust quantification of morning oscillator light responses.
Categories
Sleep & Circadian Health: Investigates how intermittent light pulse trains affect phase advances in the morning circadian oscillator, directly relevant to light-based circadian entrainment strategies.
The Science of Light: Quantifies photosensitivity differences between morning and evening circadian oscillators and identifies optimal light pulse patterns for phase shifting, informing lighting protocol design.
Author(s)
S Kaladchibachi, DC Negelspach, F Fernandez
Publication Year
2018
Number of Citations
5
Related Publications
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 two‐process 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
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