The Application of an Ultra-Thin, High-Density μECoG Array in Dissecting Caffeine-Induced Cortical Dynamics in Mice

High-density micro-electrocorticography (μECoG) arrays offer precise spatial resolution with minimal invasiveness. This study employed a custom ultra-thin 64-channel μECoG array to investigate cortical activity in mice under chronic caffeine exposure. While caffeine is known to enhance short-term alertness, its long-term impact on sleep microarchitecture and brain connectivity is unclear. Continuous recordings from adult mice during baseline and recovery revealed that prolonged caffeine intake significantly reduced broadband power spectral density (PSD) and spindle power but increased interregional coherence and altered spindle duration and density. In contrast, six hours of sleep deprivation elevated PSD and coherence, mainly affecting sensorimotor and retrosplenial cortices. These findings validate the μECoG array's functionality and demonstrate that post-chronic caffeine withdrawal lowers cortical oscillatory power yet enhances network connectivity, whereas acute sleep loss boosts global synchrony. This work clarifies how sustained caffeine use and sleep deprivation distinctly disrupt sleep homeostasis through different neural mechanisms.