Membrane Properties, Sunaptic Currents, and Intracellular Ca Transients in Transplanted Neurons in the Model Rats of Diseases of the Central Nervous System

(1)制备中枢神经系统疾病模型大鼠：采用单侧黑质注射6-羟色胺制备双侧帕金森病模型大鼠。成年大鼠单侧大脑中动脉闭塞，未成熟大鼠单侧颈总动脉结扎缺氧（8%氧）进行脑缺血。腹腔注射3-硝基丙酸诱导大鼠亨廷顿病样症状及纹状体病变。(2)上述疾病的体外模型：采用缺氧-葡萄糖剥夺新皮层切片法模拟脑缺血。LayrII/III锥体细胞由于NMDA受体的易感性，比其他层的细胞更容易发生Ca^<2+>-过载。我们还发现，GABA可能直接和/或通过介导谷氨酸- nmda的兴奋毒性，导致缺血时E_<el>移位，从而加重缺血损伤。3-硝基丙酸灌注培养的纹状体和皮质胶质细胞，更多的是通过Na^+-Ca^<2+>交换器的反向操作导致细胞Ca^<2+>过载而坏死死亡。模型大鼠脑切片移植神经元的生理实验：建立受体海马和脑缺血模型大鼠脑切片活体供体细胞的标记和鉴定方法。通过标记成功地记录了电压依赖性Na^+和K^+电流以及谷氨酸诱导的细胞内Ca^<2+>升高。在脑切片中，宿主和移植细胞之间的连接在功能上被证实为细胞内Ca^<2+>瞬变，以响应邻近宿主组织的电刺激。模型大鼠诱导基因表达检测：在3-硝基丙酸诱导的亨廷顿病样纹状体损伤中，RT-PCR法显示iNOS mRNA表达升高，免疫组化染色也显示iNOS水平与mRNA水平同步升高。少

(1) Preparing Model Rats of Diseases of the Central Nervous System : Hemiparkinsonian disease model rats were made with unilateral injection of 6-OHDA to substantia nigra. Cerebral ischemia was performed by unilateral mid cerebral artery occlusion in adult rats and by unilateral common carotid artery ligation with hypoxia (8% oxygen) in immature rats. 3-Nitropropionic acid was administered intraperitoneously to induce Huntington diesease-like symptoms and striatal lesions in rats.(2) In Vitro Model of the Diseases Described Above : Cerebralischemia was simulated by oxygen-glucose deprivation of neocortical slices. LayrII/III pyramidal cells were more vulnerable to Ca^<2+>-overload than those in the other layrs due to NMDA receptor susceptibility. We also found that GABA may aggravate ischemic damage directly and/or via mediation of glutamate-NMDA excitotoxicity as a result of E_<el> shift during ischemia. Perfusion of cultured striatal and cortical glial cells with 3-nitropropionic aci … More d caused cellular Ca^<2+>-overload leading to necrotic deathby reverse operation of Na^+-Ca^<2+> exchanger.Physiological Experiments on Transplanted Neurons in Brain Slices from the Model Rats : We established methods for labeling and identification of living donor cells in brains slices of recipient himiparkinsonian and cerebral ischemia model rats. Voltage dependent Na^+ and K^+ currents as well as glutamate-induced intracellular Ca^<2+> increase were successfully recorded from the grafted cells identified by the labeling. Interconnection between the host and grafted cells was functionally proved in brain slices as intracellular Ca^<2+> transients in response to the electrical stimulation of neighboring host tissue.Detection of Gene Expression Induced in the Model Rats : In the 3-nitropropionic acid-induced Huntington disease-like striatal lesion, expression of iNOS mRNA increased as revealed by RT-PCR method Immunohistochemical staining also showed an increased level of iNOS in parallel with mRNA. Less