Summary
This study demonstrates that PACAP/PAC1 signaling plays a modulatory role in light-regulated food anticipatory activity, with PAC1 knockout mice showing a nearly 3-fold increase in FAA amplitude and advanced FAA onset under skeleton or low-intensity photoperiods compared to wild types. These findings suggest that the quality and structure of light exposure (not just presence/absence) influences circadian behavioral responses through specific retinal neuropeptide pathways, with implications for how lighting environments may be designed to modulate circadian-driven behaviors.
Key Findings
- PAC1-/- mice showed a nearly 3-fold increase in food anticipatory activity (FAA) amplitude compared to wild-type mice under skeleton photoperiod (SPP) at 300 lux
- PAC1-/- mice demonstrated advanced onset of FAA relative to PAC1+/+ littermates under SPP conditions
- At low light intensity (10 lux), enhanced FAA was observed in PAC1-/- mice under both full and skeleton photoperiods, suggesting light intensity modulates PACAP/PAC1 signaling effects
- Both PAC1-/- and PAC1+/+ mice successfully entrained to full and skeleton photoperiods at 300 and 10 lux, indicating PAC1 is not required for basic light entrainment
Categories
Sleep & Circadian Health: Investigates how PACAP/PAC1 signaling in ipRGC light pathways modulates circadian food anticipatory activity rhythms under different photoperiod conditions.
The Science of Light: Examines the role of PACAP neurotransmitter and PAC1 receptor in transmitting non-image-forming light information from ipRGCs to regulate circadian behavior.
Author(s)
J Hannibal, B Georg, J Fahrenkrug
Publication Year
2016
Number of Citations
15
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 twoāprocess 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