Fig. 2.
Isoflurane impairs cognitive functions via mammalian target of rapamycin activity. (A) Novel object recognition test (NOPR). On day 1, mice were allowed to explore two identical objects in an opaque chamber. On day 2, one object was moved to a novel position. Exploratory behavior was defined as the number of object-contacting with snouts. (B) Y-maze test. On day 1, mice habituated in the start arm and one choice arm. On day 2, the animal could choose between two arms. Exploration time in both arms was respectively recorded. (C) Novel object recognition test for rapamycin study. Control animals made more contact with the object in the novel position than that in the old position. Isoflurane-exposed mice have identical contacts for both positions. Rapamycin treatment restores performance to near control levels. (D) Y-maze study. Control animals stayed in the novel arm for longer time than in the old arm. Isoflurane-exposed animals stayed in both arms for same time. Rapamycin treatment reversed this ratio to near control. (E) Novel object recognition test for clemastine study. Control animals spent more time exploring the object in the novel position, but isoflurane-exposed animals exhibited no exploration preference. Clemastine treatment increased difference near the level of control animals. (F) Y-maze test. Similarly, isoflurane mice spent identical time for both arms, but this effect of isoflurane was reversed by feeding clemastine. The statistics were two-way ANOVA. n = 12 for each group; *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, no significance. Error bars: SD.