Pain Medicine and Intensive Care Section, Department of Surgery and Cancer, Chelsea and Westminster Hospital, Imperial College School of Medicine, London, UK.
Acta Anaesthesiol Scand. 2012 Sep;56(8):1052-7. doi: 10.1111/j.1399-6576.2012.02691.x. Epub 2012 Apr 4.
The aim of this study is to investigate the effect of general anaesthesia induced by isoflurane with buprenorphine on hippocampus-dependent and neocortex-dependent memory, respectively, in mice, and in addition, to compare the effects of such anaesthesia on these memory processes with the effects induced by lipopolysaccharide (LPS) administration on the same memory processes.
To assess hippocampus-dependent memory, isoflurane (for 15 min) after buprenorphine injection, or LPS 100 μg/kg (intraperitoneally) was administered 24 h before or after fear conditioning. The effect of these treatments on hippocampus-dependent memory was assessed using contextual fear-conditioning tasks at day 4. To assess neocortex-dependent memory, isoflurane anaesthesia or LPS was given 72 h after contextual fear conditioning. Neocortex-dependent memory assessment was performed at day 32.
Unlike LPS injection, isoflurane with buprenorphine-induced anaesthesia does not impair freezing responses in hippocampus-dependent fear-conditioning memory tasks. On anterograde amnesia assessment: 49.67 ± 6.87% for the anaesthesia group and 54.5 ± 4.12% for the control group. On retrograde amnesia assessment: 47.16 ± 8.71% for the anaesthesia group and 54.5 ± 4.12% for control group; P > 0.05. Thus, neither isoflurane nor buprenorphine impair hippocampus-dependent memory. However, on the neocortex-dependent memory task, both isoflurane-induced anaesthesia and LPS-induced inflammation result in reduced freezing responses: 62.13 ± 5.80% for the anaesthesia group, 74.63 ± 5.69% for the LPS group, and 81.75 ± 3.26% for the control group; P < 0.05 compared with control group.
General anaesthesia induced by isoflurane with buprenorphine may result in impairment of neocortex-dependent memory in mouse. However, general anaesthesia so induced does not impair hippocampus-dependent memory in mouse in our experimental conditions.
本研究旨在分别探讨异氟醚复合布托啡诺诱导的全麻对小鼠海马依赖性和新皮质依赖性记忆的影响，并比较这种麻醉对这些记忆过程的影响与脂多糖（LPS）给药对相同记忆过程的影响。
为评估海马依赖性记忆，在恐惧条件反射前 24 小时或后 24 小时给予异氟醚（15 分钟）和布托啡诺，或 LPS（100μg/kg，腹腔内注射）。在第 4 天使用情境恐惧条件反射任务评估这些治疗对海马依赖性记忆的影响。为评估新皮质依赖性记忆，在情境恐惧条件反射后 72 小时给予异氟醚麻醉或 LPS。在第 32 天进行新皮质依赖性记忆评估。
与 LPS 注射不同，异氟醚复合布托啡诺诱导的麻醉不会损害海马依赖性恐惧条件反射记忆任务中的冻结反应。在前向遗忘评估中：麻醉组为 49.67±6.87%，对照组为 54.5±4.12%。在逆行性遗忘评估中：麻醉组为 47.16±8.71%，对照组为 54.5±4.12%；P＞0.05。因此，异氟醚和布托啡诺均不会损害海马依赖性记忆。然而，在新皮质依赖性记忆任务中，异氟醚诱导的麻醉和 LPS 诱导的炎症都会导致冻结反应减少：麻醉组为 62.13±5.80%，LPS 组为 74.63±5.69%，对照组为 81.75±3.26%；与对照组相比，P＜0.05。
异氟醚复合布托啡诺诱导的全麻可能导致小鼠新皮质依赖性记忆受损。然而，在我们的实验条件下，这种麻醉不会损害小鼠的海马依赖性记忆。
