General anesthesia and natural sleep share some commonalities and some differences. Quite a lot is known about the chemical and neuronal effects of general anesthetic drugs. There are two main groups of anesthetic drugs, which can be distinguished by their effects on the EEG. The most commonly used drugs exert a strong GABAergic action; whereas a second group is characterized by minimal GABAergic effects, but significant NMDA blockade. It is less clear which and how these various effects result in failure of the patient to wake up when the surgeon cuts them. I will present some results from experimental brain slice work, and theoretical mean field modelling of anesthesia and sleep, that support the idea that the final common mechanism of both types of anaesthesia is fragmentation of long distance information flow in the cortex.