Delayed recovery of behavior after anesthesia in rats

Abstract

Early, complete recovery from general anesthesia is of importance for out-patients, in resuscitation research and in behavior testing of neonates. A model was designed to study behavior during the first week of recovery from anesthesia in rats, using two methods: spontaneous and unrestrained locomotor activity was tested and passive avoidance of electroshock was studied in a two session, one trial model. Neurologic deficit and ease of handling were also tested After anesthesia with halothane 1 2% in N 2O/O 2 for 30 min, spontaneous activity was reduced, compared with unanesthetized rats, for up to at least 48 h. On day 6 post-anesthesia, locomotor activity was recovered, and, on days 4 and 5, passive avoidance was unchanged. Neurologic deficits were absent after the first hour of recovery and ease of handling was unchanged. Conclusion: Halothane and nitrous oxide have prolonged effects on locomotor behavior beyond the immediate post-anesthesia recovery period, at a time when neurologic deficit testing does not reveal any abnormalities. The model is suitable for the comparison of recovery from different anesthesia techniques in rats.