Altered dynamical integration/segregation balance during anesthesia-induced loss of consciousness.
Frontiers in network physiology January 1, 2023 Louis-David Lord, Timoteo Carletti, Henrique Fernandes et al.
Normal waking consciousness requires a balance between global integration (long-distance brain interactions) and segregation (local processing). Altered states, such as anesthesia, tip this balance. Using electrocorticography (ECoG) in a monkey under ketamine or propofol anesthesia, the study examined band-specific synchronization across the whole brain and within localized clusters. Both anesthetics caused a loss of long-range integration in multiple frequency bands, most pronounced in beta (13-30 Hz) and low-gamma (30-80 Hz) bands, while local synchrony was strongly preserved in all bands. This demonstrates a shift away from the integration/segregation equilibrium at sub-second time scales.