Summary
This study demonstrates that peripheral tissues (adrenal gland, liver, brown adipose tissue) possess active circadian clock machinery that is entrained by temperature rather than direct light exposure, with TRPV1 channels playing a key mediating role. For lighting design, this supports the idea that light entrains the central clock (SCN) via melanopsin, which then regulates circadian body temperature rhythms that synchronize peripheral tissues — underscoring the systemic importance of appropriate light-dark cycles.
Key Findings
- A 10-minute pulse of blue light at 650 lux did not act as a synchronizer in B16-F10 Per1::Luc cells, which remained in free-running rhythm.
- A temperature pulse of +2.5°C above maintenance temperature for 1 hour was sufficient to adjust Per1 gene expression and impose a circadian rhythm in peripheral cells.
- TrpV1 showed rhythmic transcription in liver and brown adipose tissue of mice under light-dark (LD) conditions, supporting its role as a mediator of light-to-peripheral-tissue signaling via temperature.
- In TrpV1 KO mice maintained in LD, probable compensatory upregulation of TrpA1 expression was observed in the liver.
- Brown adipose tissue did not express TrpA1, distinguishing it from liver and adrenal gland in terms of TRP channel profile.
Categories
Sleep & Circadian Health: Investigates how light and temperature entrain peripheral clock gene expression (Per1, Per2, Clock, Bmal1) in mammalian tissues, directly relevant to circadian rhythm mechanisms.
The Science of Light: Examines melanopsin and rhodopsin as potential thermoreceptors and their role in relaying photic information to peripheral clocks via TRP channels and body temperature regulation.
Author(s)
NF Mezzalira
Publication Year
2015
Number of Citations
1
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