Circadian and dark-pulse activation of orexin/hypocretin neurons
Author Information
Author(s): Marston Oliver J, Williams Rhîannan H, Canal Maria M, Samuels Rayna E, Upton Neil, Piggins Hugh D
Primary Institution: Faculty of Life Sciences, University of Manchester, Manchester, UK
Hypothesis
How do circadian and arousal-promoting signals interact to regulate orexin neuron activation?
Conclusion
The study demonstrates that orexin neuron activation is under pronounced circadian control and is selectively activated by stimuli that reset the SCN circadian clock.
Supporting Evidence
- Under constant light, orexin neurons showed higher activation during the subjective night compared to the subjective day.
- Dark pulses during the subjective day activated orexin neurons and suppressed SCN activity.
- More than half of the medial orexin neurons were activated during dark pulse exposure.
Takeaway
This study shows that certain brain cells that help control sleep and wakefulness are active at different times of the day and can be turned on by darkness.
Methodology
Mice were placed in constant light conditions and exposed to dark pulses to assess the activation of orexin neurons using c-Fos as a marker.
Limitations
The study primarily focuses on male C57BL/6J mice, which may limit the generalizability of the findings to other species or sexes.
Participant Demographics
Adult male C57BL/6J mice were used in the study.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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