Summary
This research reveals that stress-induced disruption of circadian rhythms operates through glucocorticoid signaling to alter PER1 clock protein expression in brain regions governing emotion and stress responses, while the master clock (SCN) remains unaffected. For lighting and wellbeing applications, this suggests that circadian disruption from stress may compound or interact with light-driven circadian dysregulation, particularly in emotional and psychiatric contexts.
Key Findings
- The SCN (master circadian pacemaker) remained immune to all stress manipulations, while peripheral brain clocks in the limbic forebrain and hypothalamus were strongly affected
- Systemic stressors increased PER1 expression in the piriform cortex, paraventricular and dorsomedial nuclei, and central extended amygdala; processive stressors suppressed PER1 in the central extended amygdala
- Fear (a complex processive stressor) produced PER1 expression patterns in the central extended amygdala characteristic of systemic stress, suggesting modality-specific circadian clock regulation
- Stress-induced PER1 expression in most regions (excluding piriform cortex and SCN) was dependent on glucocorticoid receptor signaling, confirmed via adrenalectomy and pharmacological GR blockade
- Time of day of stress exposure was identified as a critical factor influencing PER1 response magnitude and pattern
Categories
Sleep & Circadian Health: Demonstrates how stress disrupts circadian clock protein PER1 expression in forebrain and hypothalamic regions, with implications for circadian rhythm disruption.
Mood & Mental Wellness: Identifies PER1 as a potential intermediary between circadian systems and emotional state regulation, particularly in limbic regions associated with fear and stress.
Author(s)
S Al-Safadi
Publication Year
2014
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