神经发生对小鼠学习记忆能力的影响

The effect of neurogenesis on learning and memory of the mice

本研究探讨神经发生对学习记忆能力的影响。选择健康成年昆明小鼠随机分7组,分别为生理盐水对照组,酸性成纤维细胞生长因子(aFGF)高、中、低剂量组,甲氨喋呤(MTX)高、中、低剂量组。使用脑立体定位仪行侧脑室埋管手术及侧脑室微量注射。用Morris水迷宫训练测试其空间学习与记忆能力;腹腔注射5-溴脱氧尿苷(BrdU)后通过免疫组织化学方法来显示Br-dU阳性细胞。结果表明,aFGF各剂量组学习记忆能力均强于生理盐水对照组;MTX高剂量组学习记忆能力显著低于生理盐水对照组。免疫组织化学结果显示aFGF各剂量组齿状回内BrdU阳性细胞数目显著高于对照组;而MTX高剂量组齿状回BrdU阳性细胞较之显著减少。结果提示,aFGF和MTX可能通过促进或抑制齿状回的神经发生,从而影响小鼠的学习与记忆能力。

The present study was designed to investigate the effect of neurogenesis on learning and memory of the mice. Adult healthy Kunming mice were randomly divided into 7 groups, the control group, acidic fibroblast growth factor （aFGF） high, middle, low dosage groups and Methotrexate （MTX） high, middle, low dosage groups, respectively. Use brain three-dimensional orientation apparatus operates implanting cannulae into the lateral ventricle, and every group was injected with microsyringe. We tested the spatial learning and memory ability of mice through the Mort＇is Water Maze （MWW） training. We used the methods of immunohistochemistry to label the BrdU ^＋ cells with 5-bromodeoxyuridine （BrdU）. The results show that spatial learning and memory capability of every dosage groups of aFGF were higher then that of control; The spatial learning and memory capability of the high dosage group of MTX was lower then that of control. The number of BrdU ^＋ cells in dentate gyrns（DG） was more in every dosage groups of aFGF than that in control group. However, the number of BrdU ^＋ cells in dentate gyrus was less in the high dosage group of MTX than that in control group. Our results suggest that aFGF, MTX could effect the learning and memory capability of the mice by promoting or restraining the neurogenesis in DG.