原代培养神经细胞膜经N—甲基—D—D天冬氨酸和MK—801作用后原子力微镜观察

目的：对比观察正常培养皮层神经元在N－甲基－D－天冬氨酸（NMDA）及其受体拮抗剂－MK－801作用下膜表面三维构像形态的改变。方法：利用分辨率为0．1－0．01nm的原子力显微镜（AFM）对原代培养大鼠皮层神经细胞膜表面进行纳米尺度的扫描观测。结果：正常神经元膜表面光滑，起伏均匀，隆起的颗粒状蛋白密集，间隔规律。NMDA损伤后神经元破碎，崩解，膜失去连续性，NMDA＋MK－801作用下神经元膜皱折增加，边缘粗糙，起伏程度介于前两者之间，结论：（1）AFM具有分辨率高，制样简单特点，（2）AFM能细微地分辨损伤保护作用后引起的细胞膜表面三维形态改变。（3）NMDA作用后膜结构开始解体，膜蛋白颗粒聚集增大，脂质凹陷加深，间距增宽，表面粗糙度增加。

Atomic force microscopic observation of the neurons membrane in primary culture after treatment with N-Methyl-D-Asph]

OBJECTIVE: To observe the changes in three-dimensional morphology of the membrane of the cortex neurons in primary culture in response to treatment with N-Methyl-D-Asp (NMDA) and MK-801 using atomic force microscope (AFM). METHODS: Following NMDA treatment, the changes in the membrane of the neurons fixed by glutaraldehyhyde were examined, and the protective effect of MK-801 on the neurons was also observed using an ATM at the resolution of 0.01-0.1 nm. RESULTS: Normal neurons presented smooth membrane surface with regular undulation and densely but well arrayed protein granules. In response to NMDA treatment, the neurons were disrupted, falling into small pieces, and their membrane appeared discontinuous. MK-801 treatment increased the folds of the membrane that showed rough edges, with membrane undulation only secondary to normal condition. CONCLUSION: AFM, with the merits of high resolution and easy sample preparation, can finely display the three-dimensional morphology of the surface of the neurons, which, after NMDA treatment, becomes disintegrated with increased bulk of the protein granules, deepened caving of the lipids, and rougher membrane surface.