Sevoflurane Increases Locomotion Activity in Mice

Clinical observation shows emergence agitation and hyperactivity during the induction and/or recovery of anesthesia. However, an animal model to illustrate this clinical phenomenon has not been established. We therefore set out to investigate whether sevoflurane, a commonly used anesthetic, could alter locomotion in the mice during the induction and recovery of anesthesia. The activity of mouse was recorded 5 minutes before, during (for 30 minutes) and 40 minutes after the administration of anesthetic sevoflurane [1-, 1.5- and 2-fold minimum alveolar concentration] at 37 oC. The total walking distance and velocity of movement were measured and quantified as the indexes of locomotion. We found that the anesthetic sevoflurane increased the locomotion of the mice during the induction of the anesthesia. During the recovery phase after anesthesia, the mice exhibited increased locomotion for a short period of time (about 5 minutes) and then displayed a sharp decrease in mobility for up to 60 minutes following the end of anesthesia administration. The anesthetic sevoflurane did not significantly alter the food intake and body weight of the mice. Furthermore, we found that Alzheimer’s disease transgenic mice exhibited a greater sevoflurane-induced hyperactivity than the wild-type mice did. Our results showed that inhalation of the anesthetic sevoflurane induced an acute hyperactivity in mice, particularly among Alzheimer’s disease transgenic mice. These findings from the pilot studies established an animal model to promote further studies into postoperative emergence agitation, hyperactivity and the underlying mechanisms of these conditions.