Impact of the light profile on circadian and homeostatic markers in the sleep-wake switching model

Background and Objectives: The goal of this work is to study the impact of the shape of the 24-hour light profile on the behavior of the «sleep-wake» switching model using physiological markers: the time of minimum core body temperature, the time of melatonin peak of plasma, and sleep and wake times. Based on them, you can conclude about the synchronism between circadian, homeostatic and daily rhythms, which is an important criterion for normal human life. Mathematical model: We used the trigger population model of arousal state dynamics, which demonstrates the most realistic process of “sleep-wake” and is based on numeric experimental data. By the means of a mathematical model, we calculated the values of physiological markers and studied the influence of the daily intensity profile on them. Results: As a result of our study, we have found that the light profile, represented by a harmonic function, differs in its impact from non-differentiated forms of profiles and has a stronger influence on the moments of switching between sleep-wake states than on the duration of these states. Also, in the process of our work, we have shown that the shape of the cycle a light-dark is important in the synchronous regime, while at low values of light intensity (synchronism is absent), it has a negligible effect on the behavior of the system and it is required to proceed to the assessment of their dynamics over time. Conclusion: Features of the shape of the light profile must be taken into account when developing experimental protocols.