Gene expression of brain regions activated by sevoflurane and propofol

The basic mechanisms of action for general anesthesia are not fully understood. We thought differences in the neural activation sites of different types of anesthetics and differences in gene expression changes in those brain regions may lead to differences in the incidence of side effects. We performed gene expression analysis using microarrays in the identified regions that have been related to the mechanisms of anesthetic action and side effects. Gene expression changes in these brain regions were determined for sevoflurane and propofol to understand the mechanisms that cause differences among anesthetics. Rats were exposed to 40% oxygen at a flow rate of 6 L/min during anesthetic treatment. Rats were randomly allocated to four groups: propofol (intravenous 36 mg/kg/hr after a 10 mg/kg bolus dose), intralipos (10% lipid, intravenous 36 mg/kg/hr after a 10 mg/kg bolus dose), 2.4% sevoflurane (1 minimum alveolar concentration (MAC) in rats, and O2 treatment. Rats were anaesthetized with sevoflurane or propofol for 1 hour. Among the brain regions with anesthesia-induced changes in neuronal activity, gene expression analysis was performed in the lateral habenula (LHb), the medial habenula (MHb), the solitary nucleus (Sol) and the medial vestibular nucleus (MVe) from laser microdissected samples.