Mathematical modeling of how light affects stress hormone regulation and its impact on timing of body clocks

A semimechanistic model predicts that photic stimulation increases cortisol sensitivity during its rising phase and shortens its period under constant light conditions.

• The model suggests a type-1 phase response curve for cortisol related to light exposure.
• Cortisol's phase and amplitude are dependent on light and dark cycles.
• High variability in cortisol amplitude occurs when light and dark periods are balanced.
• Disrupted light schedules may lead to reduced cortisol secretion and loss of circadian rhythmicity in peripheral clock genes.

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