To investigate the effects of IGF-1 on the abilities of learning and memory and intracellular calciumin brain of rats with dementia.MethodsWe established the dementia rat models by transecting bilateral fornix-fimbria and di-vided them into five groups: normal control group, sham group, dementia group, low dose IGF-1 group and large dose IGF-1 group. Dementia model rats received IGF-1 (low dose IGF-1 group, large dose IGF-1 group) or saline (sham group, dementia group) by infusion into the cerebroventricular space for 21 days after operation. The normal control group received no treatment. The learning and memory abilities were measured by Morris water maze,and We use confocal laser scanning microscope to de-tecte calcium ion in brain cell.ResultsThe low dose IGF-1 group and the large dose IGF-1 group compared with the dementiagroup shows the escape latency decreased and the spanning platform times increased (P<0.01). The low dose IGF-1 group compared with the large dose IGF-1 group shows the escape latency decreased and the spanning platform times increased (P<0.01 or P<0.05). Calcium ion in brain cell was decreased obviously of low dose IGF-1 group and large dose IGF-1group compared with the dementia group (P<0.01). The difference of Calcium ion in brain cell of low dose IGF-1 group was significant compared with large dose IGF-1group (P<0.01 or P<0.05).The results show that IGF-1 can keep the balance ofCalcium ion in brain cell, and inhibit cell apoptosis, ameliorate the learning and memory ability of rats.%目的 探讨胰岛素样生长因子-1(IGF-1)对痴呆模型大鼠学习记忆能力及脑细胞内Ca2+的影响.方法 本研究采用切断成年Wistar大鼠双侧穹窿海马伞,建立隔-海马胆碱能系统损害的痴呆模型.分为正常对照组、假手术组、痴呆组、小剂量IGF-1组、大剂量IGF-1组.痴呆模型制备1d后开始侧脑室给药,连续21d.正常对照组不给予任何处置.利用水迷宫观察其行为学改变,应用激光共聚焦显微镜观察各组大鼠脑细胞内Ca2+的荧光强度.结果 (1)小剂量IGF-1组和大剂量IGF-1组与痴呆组相比,逃避潜伏期明显减少,跨越平台次数明显增多(P＜0.01);(2)IGF-1治疗小剂量组与大剂量组相比,逃避潜伏期明显减少,跨越平台次数明显增多(P＜0.01或P＜0.05).激光共聚焦显微镜检测结果:(1)小剂量IGF-1组、大剂量IGF-1组脑细胞内Ca2+荧光像素值与痴呆组比较均明显降低,具有统计学差异(P＜0.01);(2)小剂量IGF-1组与大剂量IGF-1组相比,荧光像素值差异有统计学意义(P＜0.01或＜0.05).结论 IGF-1通过调节痴呆模型大鼠Ca2+水平来改善其学习记忆能力.
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