Abstract
Nearly 170 years have passed since William Morton successfully demonstrated the use of inhaled ether for surgical anesthesia in 1846. During the last 40 years, the development of new anesthetics and safe general anesthesia techniques have contributed greatly to the advancement of surgery and other invasive procedures. Although the general anesthetic state comprises multiple components (amnesia, unconsciousness, analgesia, and immobility), each of which is mediated by effects on different neurotransmitter receptors and neuronal pathways, it is not clear as yet whether a patient is having memories during anesthesia and is able to recall them after anesthesia. In several of my own patients, I could not understand what happened in the anesthetized brain, especially in inferring same gaps between amnesia and unconsciousness. The neural mechanisms by which the state of general anesthesia is achieved are only just beginning to be understood. In this brief review, I report five anesthetic cases and focus on the mechanisms of anesthetic action with respect to unconsciousness and memory consolidation involved in mediating the clinically relevant events such as awareness during anesthesia.
