颞叶癫痫小鼠慢性期的条件恐惧记忆变化及海马神经元树突棘的形态改变

Changes of Fear Conditioning Memory and Morphology of Dendritic Spines in Hippocampal Neurons in the Chronic Phase of Mice with Temporal Lope Epilepsy

【目的】探讨颞叶癫痫小鼠慢性期的条件恐惧记忆变化及海马神经元树突棘的形态改变。【方法】腹腔注射海人酸（KA）构建海人酸颞叶癫痫模型8只为KA组，腹腔注射生理盐水4只为对照组（CN组）。2个月后，对两组进行条件恐惧记忆实验，并用高尔基染色法观察小鼠海马神经元树突棘变化。【结果】KA组小鼠场景联系性恐惧记忆僵直时间百分比为（17．50±0．88）％，明显低于CN组的（60．24±3．01）％，其差异有统计学意义（P〈0.05）。KA组小鼠声音联系性恐惧记忆的僵直时间百分比为（49．0l±2．45）％，明显低于CN组小鼠的（79．57±3．98）％，其差异有统计学意义（P〈0．05）。高尔基染色结果显示KA组小鼠海马神经元树突棘的密度显著降低。图像分析的结果显示，KA组小鼠海马神经元树突棘长度、海马神经元树突棘的密度分别为（2．1±0．11）μm、（10±0．5）个／10μm，明显低于CN组的（2．5±0．13）μm、（12±0．6）个／10gm，其差异均有统计学意义（P〈0．05）。【结论】KA颞叶癫痫小鼠慢性期有条件恐惧记忆障碍，这可能与海马神经元树突棘的形态改变有关。

[Objective]To investigate the changes of fear conditioning memory and the morphological changes of den- dritic spines in hippoeampal neurons in the chronic phase of mice with temporal lobe epilepsy.[Methods]l Temporal lobe epilepsy models were induced by intraperitoneal injection of Kainic acid （KA） in mice. The mice were divided into two groups： KA group （n=8） which received KA and the control group （CN, n =4） which were intraperitoneal injection of saline instead. After two months, emotional learning and memory were evaluated by fear-conditioning test, and changes in dendritic spines of hippocampal neuron in both groups of mice were observed by Golgi Staining. [Results]In the contextual test, the percentage of connective fear memory freezing time in the KA group was （17.50±0.88）%, which was significantly lower than that in the CN group （60.24±63.01）%, and the difference was statistically significant （ 〈0.05）. In the tone cued test, the percentage of freezing time in the sound-connected fear memory of the KA group was （49.01± 2.45） %, which was significantly lower than that of the CN group （79.5 ±3.98）%, and the difference was statistically significant （ P〈0.05）. Compared to the control group, Golgi staining showed that the density of dendritic spines in hippocampal neurons in KA group was significantly reduced. The results of image analysis showed that the dendritic spine length of hippocampal neurons and the density of dendritic spines of hippocampal neurons in KA group were （2.1± 0.11 ）μm, （10!0,5）/10 μm, respectively, which were significantly lower than that d CN group. （2.5±0.13） /am, （12± 0.6）/10μm, respectively, and the differences were statistically significant （ P〈0.05）.[Conclusion]The mice with KA- induced temporal lope epilepsy in chronic phase have the impaired fear conditioning memory, which may be associated with the morphological changes of of dendritic spines in hippocampal neurons.