Propofol anesthesia destabilizes neural dynamics across cortex

Adam Joseph Eisen, Leo Kozachkov, Andre M Bastos, Jacob A. Donoghue, Meredith K. Mahnke, Scott L Brincat, Sarthak Chandra, John Tauber, Emery N. Brown, Ila R Fiete, Earl K Miller

Abstract:

Every day, hundreds of thousands of people undergo general anesthesia. One hypothesis is that anesthesia
disrupts dynamic stability—the ability of the brain to balance excitability with the need to be stable and
controllable. To test this hypothesis, we developed a method for quantifying changes in population-level dy-
namic stability in complex systems: delayed linear analysis for stability estimation (DeLASE). Propofol was
used to transition animals between the awake state and anesthetized unconsciousness. DeLASE was applied
to macaque cortex local field potentials (LFPs). We found that neural dynamics were more unstable in uncon-
sciousness compared with the awake state. Cortical trajectories mirrored predictions from destabilized linear
systems. We mimicked the effect of propofol in simulated neural networks by increasing inhibitory tone. This
in turn destabilized the networks, as observed in the neural data. Our results suggest that anesthesia disrupts
dynamical stability that is required for consciousness.