Anesthesia and the Thalamocortical System

Abstract

Neuroimaging the effect of anesthesia in the human brain reveals that anesthesia suppresses the functioning of the brain both in a global- and regional-specific manner. The suppression of activity generally has a global component to it (i.e., the entire brain seems to shut down), but on top of that a few select regions appear to be more suppressed than the rest of the brain (i.e., some areas appear to be more sensitive to the suppression effects of anesthesia). These regionally sensitive areas include the parietal and frontal cortical regions along with a consistently observed effect that shows a suppression of thalamic activity. It remains unknown as to which of these effects caused by anesthesia are the most important for producing a loss of consciousness. This chapter will discuss some recent findings from anesthesia research that serve to implicate a role for the thalamocortical system in mediating consciousness.