Functions of DISC1 and APP in Cortical Development and Neuropsychiatric Disorders

皮质细胞迁移缺陷与一系列表型有关，包括癫痫、精神障碍 智力低下、自闭症和精神分裂症(SZ)。在过去，对人类基因的功能分析与 经典的神经元迁移障碍为研究迁移途径提供了有价值的见解。 以及这些疾病的根本原因。对啮齿动物的研究增加了更多的因素 迁徙所必需的基因。其中一个因素是淀粉样前体蛋白(APP)，这是一种阿尔茨海默病 连接基因，这是正常迁移到皮质板和神经元突起所必需的 外延生长。此外，一些基因与精神分裂症有关，如D1SC1、PDE4和NRG1， 所有这些都在神经元发育中发挥重要作用，包括迁移和轴突生长。近期 研究将涉及AP0ER2、DAB1和LIS1等因素的经典迁移途径与这两个APP联系起来 和某些SZ连锁基因。这项提议旨在1)将这些新确定的参与者整合到 已建立的迁移和轴突生长途径；2)阐明某些突变和变异是如何 SZ相关基因导致迁移缺陷；以及3)解决迁移缺陷和/或细微缺陷 神经元突起生长的变化导致神经递质及其受体水平的变化，两者 其中一种是在SZ患者中描述的。将采用体内电穿孔的方法 表达编码野生型或突变型候选蛋白的shRNA或cDNA以评估 它们的表达变化对胚胎大鼠脑内神经元前体迁移的影响。 原代神经元培养也将被用来分析这些不同结构对神经细胞的影响。 过程产生的结果。最后，神经递质受体的表达(使用生化和 免疫组织化学)和神经递质水平(使用微透析和高效液相色谱)将在 不同的基因操作导致不同程度的皮质紊乱的啮齿动物 迁移。这组实验将解决这样一个假设，即神经元迁移的异常是 与SZ患者观察到的神经递质系统缺陷有关。

Defects of cortical cell migration have been linked to a spectrum of phenotypes that include epilepsy, mental retardation, autism, and schizophrenia (SZ). In the past, functional analyses of human genes linked to classic disorders of neuronal migration have yielded valuable insights into the pathways involved in migration and the underlying causes of these diseases. Studies in rodents have added additional factors to the list of genes necessary for migration. One such factor is Amyloid Precursor Protein (APP), an Alzheimer's Disease linked gene, which is required for both normal migration into the cortical plate and neuronal process outgrowth. In addition, several genes have been linked to schizophrenia such as D1SC1, PDE4, and NRG1, all of which play important roles in neuronal development, including migration and neurite outgrowth. Recent studies link classic pathways of migration involving factors such as AP0ER2, DAB1, and LIS1 with both APP and certain SZ-linked genes. This proposal aims to 1) integrate these newly identified players into established migration and neurite outgrowth pathways; 2) elucidate how certain mutations and variants in SZ-associated genes lead to defects in migration; and 3) address whether defects in migration and/or subtle alterations in neuronal process outgrowth lead to altered levels of neurotransmitters and their receptors, both of which are described in patients with SZ. The in vivo method of in utero electroporation will be used to express shRNAs or cDNAs encoding wild type or mutated versions of candidate proteins to assess the effects of their altered expression on neuronal precursor migration in the context of the embryonic rat brain. Primary neuronal cultures also will be utilized to analyze the effects of these various constructs on neuonal process outgrowth. Lastly, both neurotransmitter receptor expression (using biochemistry and immunohistochemistry) and neurotransmitter levels (using microdialysis and HPLC) will be analyzed in rodents in which different genetic manipulations have caused varying degrees of disordered cortical migration. This set of experiments will address the hypothesis that abnormalities in neuronal migration are linked to defects in the neurotransmitter systems that are observed in patients with SZ.