New Light and Dark Schedules with Minimal Light May Disrupt the Body’s Internal Clock: Computer Model Simulations

A novel light/dark regimen can disrupt circadian rhythms using only minimal light exposure per day.

• Computer simulations suggest that a single light pulse each day may disturb circadian rhythmicity if the timing of pulses is randomly distributed.
• The underlying 24-hour periodicity may still be preserved with pulse intervals as large as 14 hours, indicating some detection of day/night cues.
• Rhythmicity loses day-to-day correlation only when light pulses are spread throughout the entire 24-hour day.
• Stronger and brighter light pulses may further exacerbate the disruptive effects on circadian rhythms.
• This light/dark schedule could facilitate in vivo bioluminescence assays to study circadian disruption and its associated health effects.

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