RESUMO
We showed the effect sites of anesthetics in the central nervous system (CNS) network. The thalamus is a key factor for loss of consciousness during natural sleep and anesthesia. Although the linkages among neurons within the CNS network in natural sleep are complicated, but sophisticated, the sleep mechanism has been gradually unraveled. Anesthesia disrupts the link-ages between cortical and thalamic neurons and among the cortical neurons, and thus it loses the integration of information derived from the arousal and sleep nuclei. It has been considered that anesthesia does not share the common pathway as natural sleep at the level of unconsciousness, because anesthetics have multiple effect sites within CNS network and may induce disintegration among neurons. Recent literatures have shown that the effects of anesthetics are specific rather than global in the brain. It is interesting to note that thalamic injection of anti-potassium channel materials restored consciousness during inhalation anesthesia, and that the sedative components of certain intravenous anesthesia may share the same pathway as natural sleep. To explore the sensitivity and susceptibility loci for anesthetics in the thalamocortical neurons as well as arousal and sleep nuclei within CNS network may be an important task for future study.