丰富环境通过促进海马CA3区突触重塑改善慢性脑缺血大鼠记忆减退的机制研究

关键词：丰富环境  慢性脑缺血  突触重塑  记忆减退

Keywords:enriched environments  chronic cerebral ischemia  synaptic remodeling  memory impairment

摘要：

      摘要 目的：探讨丰富环境改善慢性脑缺血大鼠记忆功能减退的内在机制。 方法：选取48只健康雄性SD大鼠，用随机数字表法将大鼠分为慢性脑缺血+标准环境组（CCH+SE），慢性脑缺血+丰富环境组（CCH+EE），假手术+标准环境组（Sham+SE），每组16只。CCH+SE组和CCH+EE组采用双侧颈总动脉结扎手术构建大鼠慢性脑缺血模型，Sham+SE组除了不结扎双侧颈总动脉，其他操作与模型组相同。3组大鼠在相应环境下分别饲养21天后，采用水迷宫实验检测大鼠的空间学习及记忆功能，采用蛋白质免疫印迹检测技术及免疫荧光技术，分别检测大鼠海马CA3区BDNF、GAP-43、SYN蛋白表达水平的变化。 结果：与标准环境组相比，丰富环境组大鼠的学习及记忆功能明显改善，差异具有显著性（P<0.05）。海马CA3区BDNF、GAP-43、SYN蛋白表达水平显著升高，差异具有显著性（P<0.05）。 结论：丰富环境可以改善慢性脑缺血大鼠学习及记忆功能减退，其内在机制可能是促进了海马CA3区的突触重塑。

Abstract:

      Abstract Objective： To explore the intrinsic mechanism of enriched environment-induced improvement of memory in rats with chronic cerebral ischemia. Method： Forty-eight healthy male SD rats were randomly divided into chronic cerebral ischemia+standard environment group （CCH+SE）， chronic cerebral ischemia+rich environment group （CCH+EE）， and Sham surgery+standard environment group （Sham+SE） with 16 rats in each group. The CCH+SE group and CCH+EE group were given bilateral common carotid artery ligation surgery and a rat model of chronic cerebral ischemia was constructed. The Sham+SE group performed the same procedures as the model group without ligating bilateral common carotid arteries. Three groups of rats were raised in corresponding environments for 21 days， and their spatial learning and memory functions were tested using a water maze test. Protein immunoblotting and immunofluorescence techniques were used to detect changes of BDNF， GAP-43， and SYN proteins expressions in the CA3 region of the rat hippocampus. Result： Compared with the standard environment group， the learning and memory functions of the enriched environment group were significantly improved， with a statistically significant difference （P<0.05）. The expression levels of BDNF， GAP-43， and SYN proteins in the CA3 region of the hippocampus were significantly increased， with a statistically significant difference （P<0.05）. Conclusion： Enriched environment intervention can improve learning and memory ability in rats with chronic cerebral ischemia， and its underlying mechanism may be promoting synaptic remodeling in the hippocampal CA3 region.