Introduction of novel objects to the home cage of mice repeatedly disturbs sleep for seven days with minimal stress induction

The increasing prevalence of low sleep quality is a significant issue, particularly among adolescents, necessitating a deeper understanding of its biological consequences. In sleep research, various protocols are used for sleep deprivation or disturbance, each presenting its own set of confounding factors crucial to consider. We developed a standardized seven-day sleep disturbance protocol using daily four-hour exposures to novel objects to minimize mouse stress. Objects were selected and characterized for their wake-promoting properties, and exposure timing was structured to reduce variability and enhance experimental reliability and reproducibility. During the four hours of sleep disturbance, the mice were efficiently sleep-deprived during each exposure. Thus, the selected objects efficiently kept the mice awake also after seven days exposure. On the first day of sleep disturbance, the protocol induced a sleep deprivation effect when measured over 24 h (hours), but by the seventh day, the mice recovered the sleep loss over the 24 h. Thus, this method induces an acute sleep loss, but over days it induces a sleep disturbance and not a full sleep deprivation. Fecal corticosterone concentrations remained unchanged during the seven days of sleep disturbances, suggesting that voluntary wakefulness is not stressful. Importantly, we show that the mice compensate for their sleep loss during the week of sleep disturbance, highlighting the need for better validation of long-term sleep deprivation protocols in the sleep field to accurately separate sleep deprivation from sleep disturbance.