A Sub-Minute Resolution Prediction of Brain Temperature Based on Sleep-Wake State in the Mouse

While brain temperature is of neurobiological and clinical importance, it is still unclear which factors contribute to its daily dynamics and to what degree. We recorded cortical temperature in mice alongside sleep-wake state during 4 days including a 6h sleep deprivation, and developed a mathematical tool to simulate temperature based on the sleep-wake sequence. The model estimated temperature with remarkable precision accounting for 91% of its variance based on three main factors with the sleep-wake sequence accounting for most of the variance (74%) and time-of-day ( circadian) the least (9%). As third factor, prior wake prevalence, was discovered to up-regulate temperature, explaining 43% of the variance. With similar accuracy the model predicted cortical temperature in a second, independent cohort using the parameters optimized for the first. Our model corroborates the profound influence of sleep-wake state on brain temperature, and can help differentiate thermoregulatory from sleep-wake driven effects in experiments affecting both.