出生前后慢性铝暴露对年轻大鼠海马长时程增强的影响

Effects of chronic aluminum exposure from prenatal to postnatal on LTP in hippocampus of young rats

目的研究出生前后不同浓度慢性铝暴露对年轻大鼠海马长时程增强的影响，进一步探讨铝损害学习与记忆的突触机制。方法对照组、低浓度组和高浓度组大鼠从孕期始分别自由饮用蒸馏水、Al^3＋浓度为15mmol·L^-1和30mmol·L^-1的AlCl3水溶液；采用细胞外微电极记录法测定海马长时程增强。结果对照组大鼠海马长时程增强发生率为90．91％，低浓度组为58．33％、高浓度组为18．18％，与对照组相比，高浓度组长时程增强发生率差异有显著性（P〈0．01）。对照组大鼠群体锋电位平均相对幅值达基线值（144．09±18．43）％，低浓度组为（105．83±16．79）％，高浓度组为（91．00±18．98）％，两铝暴露组与对照组比较，群体锋电位平均相对幅值增强率均明显降低（P〈0．01），且各时点相比差异有显著性（P〈0．01）。结论出生前后慢性铝暴露损害了海马LTP的诱导与维持，导致学习与记忆功能下降。

Objective To study the change of LTP in hippocampus of young rats after chronic aluminum exposure of different concentration from prenatal to postnatal, and to go deep into the synaptic mechanism of that aluminum impairs learning and memory capacity. Methods The extracellular microelectrode technique was used to monitor the LTP. Results The occurrence of LTP in control group was 90.91% , in 0.2% -Al group was 58.33% , in 0.4%-Al group was 18.18% ,compared with the control group,in 0.4%-Al group,the occurrence of LTP was remarkably decreased（P〈 0.01 ）. The PS mean amplitudes relative to the baseline values after HFS in control group was（ 144.09 ± 18.43）% , in 0. 2%-Al group was （ 105. 83 ± 16. 79）% ,in 0.4%-Al group was （91.00 ± 18.98） % ,compared with the control group, in the Al^3＋ exposed groups, the PS mean amplitudes relative to the baseline values were significantly decreased（P 〈 0.01 ） , and the mean relative amplitude differences in relation to the baseline values at selected time periods after HFS were significantly decreased （P 〈 0.01 ）. Conclusion Aluminum exposure from prenatal to postnatal can damage the induction and maintenace of LTP in hippocampus of young rats, consquentely impair the ability of learning and memory.