不同饲养环境对局灶性脑梗死大鼠学习记忆及胆碱乙酰转移酶的影响

Effects of different environmental intervention on learning-memery ability and choline acetyltransferase expression in rats after unilateral local cerebral infarction

目的观察不同环境设置对局灶性脑梗死大鼠学习记忆能力及梗死灶周围胆碱乙酰转移酶（ChAT）表达的影响。方法将SD大鼠用电凝法造成右侧大脑中动脉阻塞模型，再分为对照组（每组5只，群居于标准笼）、探索学习组（居于迷宫笼）和丰富环境组（居于丰富环境笼）。24d时利用水迷宫试验测试大鼠学习记忆能力，28d时处死，免疫组化染色测定ChAT在梗死灶周围皮质的表达情况。结果丰富环境组大鼠逃避潜伏期最短（26．9±4．8）S，跨过原平台位置次数最多（6．1±1．1）次，其次是探索学习组[（33．6±5．1）S，（4．8±1．2）次]，对照组时间最长[（41．4±6．4）s，（3．3±0．9）次]，各组之间比较有显著差异。丰富环境组大鼠梗死灶周围ChAT表达（40．3±8．4）明显高于探索学习组（35．6±7．8）和对照组（25．4±6．5）。结论丰富环境设置可改善局灶性脑梗死大鼠的学习记忆能力，上调梗死灶周围皮层CHAT的表达。

Objective To observe the effects of different environmental intervention on the learning-mem- ory ability and choline acetyltransferase （CHAT） expression around the infarct in rats with unilateral local cerebral infarction. Methods SD rats were subjected to electric coagulation of MCA and then were assigned randomly to （1）control group（5 in each group housed in a standard cage） ,（2）learn training group（ housed in a maze cage）, （3） enriched environment group （housed in a enriched environment cage）. 24 days later, rats were trained by water maze, and then killed for immunohistochemistry staining. The expression of ChAT in peri-ischemic cortex was ex- amined. Results The escape latency of rats in enriched environment was the shortest （ （ 26.9 ± 4.8 ） s）, and the times striding over the platform was the most（6.1 ± 1.1 ） ,longer （33.6 ± 5.1 ）s and less （4.8 ± 1.2）in the learn training group, the longest （ （ 41.4 ± 6.4 ） s） and least （ 3.3 ± 0.9 ） in the control group. The positive cells of ChAT in enriched environment group （40.3 ± 8.4 ） were higher than those in learn training group （ 35.6 ± 7.8 ） and those in control group（25.4 ± 6.5 ）. Conclusion Enriched environment after MCAO could promote the learning-memo- ry ability and up-regulate the expression of ChAT in the peri-ischemic regions.