How do neurons communicate and how is their communication altered when consciousness is suppressed by anesthetics? Is there a difference in the anesthetic effect on neuronal communication over long-distances versus local circuits? How is communication restored when subjects regain consciousness? What are the critical neuronal changes necessary to restore consciousness? These are paramount questions that aid the understanding of the neuronal basis of consciousness.
Our lab was probably the first to investigate the dose-dependent effect of modern, clinically used anesthetics on cortical multineuronal activity in chronically instrumented, freely moving animals using high-density microelectrode arrays. Former experiments mostly utilized individual epidural or intracortical electrodes to measure local field potentials or multiunit activity. These methods have now been replaced by high-density microelectrode and optrode recording and stimulation.