Introduction

Abstract

Approximately 100,000 patients undergo general anesthesia in the United States every day. It may come as a surprise that, to date, we do not fully understand how general anesthetics work. That is, we do not know how they “put patients to sleep” (as is commonly said) or (as we would say) how they “suppress the mind.” We do not really have a much better understanding of how anesthetic agents prevent people or animals from moving, either spontaneously or in response to a painful stimulus, though there is good evidence that the immobilizing effect of anesthetics arises primarily from actions at the level of the spinal cord. Although their ability to prevent movement is evidently of great practical value in permitting surgical procedures to be performed, what patients really desire is that they feel no pain, that they sleep peacefully through their operation, and that they remember nothing afterward. It is quite likely that the hypnotic and amnesic effects of anesthetics, and possibly also their analgesic effects, derive primarily from actions in the brain through their modulation of intricately connected, complex network of hundreds or even thousands of specialized neuron groups.