Abstract:
Brain activity and breathing rate influence each other but it remains unclear how fine respiratory features vary across and within brain states, and how they coordinate with the micro-architecture of sleep and its associated network dynamics. Using simultaneous nasal pressure and hippocampal local field potential recordings in freely-moving mice, we show here that Wake, Rapid Eye Movement (REM) sleep, and non-REM sleep (NREM) exhibit unique respiratory signatures with distinct prominence of post-inhalation pauses. Within NREM, the emergence of pauses aligns with the infra-slow noradrenaline fluctuations and demarcate not only NREM packets traditionally defined by microarousal movements, but also shorter (~30 seconds) packets of elevated hippocampal sigma-band power. Within packets, respiratory feature changes predict moment-to-moment fluctuations in the sigma-band peak-power, even in hypoxic conditions where these infra-slow oscillations are accelerated. Overall, our findings reveal that respiratory features capture the macro- and micro-architecture of sleep, opening new windows into brain states and network computations through respiration.