MOLECULAR PROFILE OF LAMINA-SPECIFIC ALTERATIONS IN THE DLPFC IN SCHIZOPHRENIA

正如中心综述中所总结的，精神分裂症患者背外侧前额叶皮层（DLPFC）回路的异常可能在第3层比其他皮层更突出。例如，DLPFC第3层锥体神经元表现出体树突形态异常，这些变化可能优先影响该层位置的锥体神经元亚群（见项目1-刘易斯）。为了探索 与第3层中观察到的形态学改变相对应，我们提出了以下三个假设：1）DNA微阵列可以揭示精神分裂症受试者DLPFC第3层中的多个表达改变，当所有层一起分析时，这些表达改变并不明显; 2）在精神分裂症受试者DLPFC第3层中观察到的一些表达差异是投射神经元亚群特异性的;和3）分子标记， 精神分裂症患者的表达改变存在于共享共同投射靶点的锥体神经元中。这些假设是对项目1-刘易斯中提出的假设的补充，将在以下三个具体目标中进行评估。在目标1中，使用高密度cDNA微阵列，我们将比较深层3转录组与对照受试者的整个DLPFC收获物。这将确定基因，显示表达富集 在DLPFC深层3中。在此之后，使用相同的微阵列和激光解剖显微镜，我们将确定在DLPFC层3之间的精神分裂症和匹配的控制对象对mRNA表达的差异。在目标2中，我们将使用原位杂交确定最有希望的表达变化的细胞定位，并确定在投射神经元亚群中显示转录水平改变的标记物。在Aim中 3我们将通过结合猴DLPFC神经元的逆行追踪和原位杂交，使用目标2中验证的标记物，确定精神分裂症患者DLPFC锥体神经元亚群是否具有共同的投射靶点。这些调查与中心的其他项目有许多概念和技术联系，并依赖于所有拟议核心提供的支持。

As summarized in the Center Overview, abnormalities in the circuitry of the dorsolateral prefrontal cortex (DLPFC) in schizophrenia may be more prominent in layer 3 than in other cortical layers. For example, DLPFC layer 3 pyramidal neurons exhibit somatodendritic morphological abnormalities, and these changes may preferentially affect a subpopulation of pyramidal neurons in this laminar location (see Project 1-Lewis). In order to explore the molecular counterpart to the morphological alterations observed in layer 3, we propose to test the following three hypotheses: 1) DNA microarrays can uncover multiple expression alterations in DLPFC layer 3 of subjects with schizophrenia that are not evident when all layers are analyzed together; 2) Some expression differences observed in layer 3 of subjects with schizophrenia are specific for subpopulations of projection neurons; and 3) Molecular markers that show expression alterations in subjects with schizophrenia are present in pyramidal neurons that share a common projection target. These hypotheses, which are complementary to those proposed in Project 1-Lewis, will be assessed in the following three specific aims. In Aim 1, using high density cDNA microarrays, we will compare deep layer 3 transcriptomes to whole DLPFC harvests in control subjects. This will identify genes that show expression enrichment in DLPFC deep layer 3. Following this, using the same microarrays and laser dissection microscopy we will identify mRNA expression differences in DLPFC layer 3 between pairs of subjects with schizophrenia and matched controls. In Aim 2 we will determine the cellular localization of the most promising expression changes using in situ hybridization and identify markers that show altered transcript levels in a subpopulation of projections neurons. In Aim 3 we will determine whether the subpopulations of DLPFC pyramidal neurons affected in schizophrenia share common projection targets by combining retrograde tracing of monkey DLPFC neurons with in situ hybridization using markers validated in Aim 2. These investigations have a number of conceptual and technical links with other Center projects and depend upon support provided by all of the proposed cores.