Circuit-level dynamics and propagation of slow wave activity modulate their interplay during the awakening process.
Antonio Pazienti, Mariel Müller, Conrado A Bosman, Umberto Olcese, Maurizio Mattia
iScience December 19, 2025 DOI: 10.1016/j.isci.2025.113954 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Mice |
| Intervention | isoflurane anesthesia |
| Keywords | Cortex Electrophysiology Laminar processing Oscillations |
| Key findings | Spectral power of slow-wave activity shifts from stronger in posterior parietal cortex during deep unconsciousness to stronger in primary visual cortex upon awakening, with state-dependent rostro-caudal propagation and recovery of layer 2/3 neuron excitability. |
Abstract
Slow-wave activity (SWA) is a hallmark of the loss of consciousness in non-REM sleep and anesthesia. The mechanistic underpinnings of SWA, and its evolution when transitioning toward the conscious brain state is poorly understood. We address this topic by recording multi-area and laminar activity in posterior parietal (PPC) and primary visual (V1) cortices of mice spontaneously awakening from isoflurane anesthesia. Spectral power is stronger in PPC (especially in superficial layers) during deep unconsciousness, but stronger in V1 when awakening. Rostro-caudal (feedback-like) propagation of SWA also shows state-dependent modulation, particularly in layer 5. The excitability of layer 2/3 neurons, hindered at high isoflurane, recovers during awakening, when V1 and the feedforward pathway reacquire a strong role. Detailing the hierarchical and laminar properties of spontaneous traveling oscillations, we provide evidence that SWA is a multiscale phenomenon. Explicating the functional role of these processes is critical to understand the neuronal mechanisms of consciousness.