BDNF和神经干细胞联用对老年痴呆鼠基底前脑 胆碱能神经元和学习记忆能力的影响

探讨脑源性神经营养因子(BDNF)和神经干细胞(NSCs)联合应用对老年痴呆大鼠基底前脑胆碱能神经元及大鼠学习记忆能力的影响。利用无血清培养技术获得新生SD鼠的海马NSCs,行BrdU标记。切断SD大鼠左侧穹隆海马伞,基底前脑注射NSCs,同时侧脑室注射BDNF,2周后行nestin和BrdU/NF、BrdU/GFAP免疫荧光双标染色,4周后行Y迷宫测试,免疫组化结合图像分析技术观察各组大鼠基底前脑神经营养因子受体(NGFR)阳性神经元数目变化。结果发现,移植后NSCs能够在宿主体内存活且分化成神经元和胶质细胞;免疫组化结果显示损伤组大鼠胆碱能神经元数在内侧隔阂(MS)和斜角带(VDB)分别减少64.3%和49.3%,较正常组明显下降(P<0.01);移植组神经元数下降34.1%和27.6%较损伤组有改善(P<0.05),但与正常组比较有显著性差异(P<0.05);联合组神经元数减少15.1%和18.6%,与正常组无显著性差异(P>0.05)。Y迷宫测试结果显示,大鼠的学习记忆能力与基底前脑NGFR阳性细胞数呈正相关。提示,BDNF和NSCs移植的联用较单独使用NSCs或BDNF更好地改善老年痴呆大鼠的学习记忆能力。

THE EFFECT OF BDNF AND NEURAL STEM CELLS UNITE APPLICATION ON CHOLINERGIC NEURONS OF THE BASAL FOREBRAIN IN MODEL RATS WITH SENILE DEMENTIA AND ABILITIES OF LEARNING AND MEMORY

To study the effect of brain derived neurotrophic factor(BDNF) and neural stem cells(NSCs) unite application on the cholinergic neurons in basal forebrain and leaning and memory in rats with Alzheimer`s disease. NSCs were obtained from hippocampus by using the serum-free culturing. NSCs labeled by BrdU were transplanted into the transected basal forebrain, then BDNF was injected into lateral ventricle. After 2 weeks, Nestin staining, BrdU/NF and BrdU/GFAP double labeled immunofluorescence were used to detect the survival and the neuronal differentiation of the BrdU labeled cells in the basal forebrain. After 4 weeks, learning and memory abilities were measured by Y-maze test. The number of basal forebrain cholinergic neurons was analyzed by using immunohistochemical method combined with technique of micromeasure and image analysis. The double labeled NSCs were observed in the basal forebrain and differentiated into neurons and astrocytes. The number of cholinergic neurons for injured groups was decreased by 64.3% and 49.3% respectively in medial septum (MS) and vertical diagonal branch(VDB), significant difference was found between the injured groups and normal control groups (P<0.01). The number for NSCs groups had a significant improvement than that of the injured groups (P<0.05),with a decrease of 34.1% and 27.6%, respectively,whereas, compared with that of normal control groups, there was still a significant difference(P<0.05); The combination groups had a nosignificant decrease of 15.1% and 18.6% respectively compared with that of normal control groups(P>0.05). The abilities of learning and memory were positively related with the number of cholinergic neurons. The above results suggest that combination treatment of BDNF and NSCs is more effective in improving the ability of spatial learning and memory in model rats with Alzheimer`s disease than treated with BDNF or NSCs alone.