冈田酸对大鼠学习记忆功能及脑内ChAT和GFAP表达的影响

EFFECTS OF OKADAIC ACID ON RAT LEARNING AND MEMORY ABILITY AND THE EXPRESSION OF CHAT AND GFAP IN THE BRAIN

为了研究冈田酸(OA)对大鼠认知能力的影响及其可能的机制,采用冈田酸进行海马CA1区微量多次注射,通过Morris水迷宫观察大鼠行为学变化,免疫组化法观察海马及皮层中ChAT和GFAP的表达。结果发现:OA注射后,大鼠平均逃避潜伏期明显延长(P<0.01),原站台象限活动时间明显缩短(P<0.01),穿越原站台次数明显减少(P<0.01)。海马及皮层中ChAT表达减少(P<0.01),而GFAP阳性反应物表达明显增多(P<0.01)。以上结果提示:OA的神经毒性可以诱导大鼠学习记忆能力的降低,其可能机制是OA导致胆碱能神经元损伤,功能低下,以及反应性星形胶质细胞的增生肥大。

In order to investigate the effect of okadaic acid （ OA ） on cognitive ability of rat and the possible mechanisms, microdosis of OA was injected into hippocamal CAI region of rat many times, and the rat behavior changes were observed by Morris water maze. In the same time, the expression of choline acetyltransferase （CHAT） and glial fibrillary acidic protein （GFAP） in the hippocampus and cortex was observed with immunohsitochemistry. After the injection of OA, the average escape latency of the rats obviously increased （P 〈 0. 01 ）, the movement time obviously shortened in plateform quadrant test （P 〈 0. 01 ）, and times of traversing platform obviously decreased （P 〈 0. 01 ）. Expression of ChAT decreased in the hippocampus and cortex（ P 〈 0. 01 ）, but the expression of GFAP obviously increased （P 〈 0. 01 ）, These results suggest that OA neurotoxicity can cause degrading of the learning and memory capability. The possible mechanisms might be related with OA-induced cholinergic neuron damage and function deficit as well as the hyperplasia and hypertrophia of the reactive astrocytes.