Post-Training Isoflurane Anesthesia Affects Memory for Object Recognition but Not for Two-Way Active Avoidance Task

Certain experimental procedures in learning and memory research require that the animal be anesthetized soon after the acquisition session. Volatile anesthetics, such as isoflurane, are good candidates for this purpose because they have both a rapid onset of effect and a quick awakening of the animal when anesthesia is discontinued. However, memory consolidation might be affected by a mixed effect of the anesthetic agent itself and the administration procedures. In the present experiment, we examined, in male Wistar rats, the effect of 15 or 60 min post-training isoflurane anesthesia on 24 h object recognition memory, a task depending on perirhinal cortex and hippocampus (Experiment I), and on 24 h or 20 days retention of a two-way active avoidance task, mainly depending on striatum and amygdala (Experiment II). The results showed that the global procedure of anesthesia with isoflurane impaired object recognition memory, but did not affect retention of two-way active avoidance, neither when tested 24 h nor 20 days after the acquisition session. We concluded that the differential effect of the treatment in these two tasks might be accounted for by an interaction of the specific features of the task and the stress produced by the administration procedure of the anesthetic agent.