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

正如中心概述中总结的那样，精神分裂症患者前额叶背外侧皮质(DLPFC)回路的异常可能在第三层比其他皮质层更突出。例如，DLPFC第3层锥体神经元表现出躯体树突的形态异常，这些变化可能优先影响这个板层位置的锥体神经元亚群(参见项目1-Lewis)。为了探索分子 与在第三层观察到的形态变化相对应，我们建议检验以下三个假设：1)DNA微阵列可以发现精神分裂症患者DLPFC第三层的多种表达变化，当所有层一起分析时，这些变化并不明显；2)在精神分裂症患者第三层观察到的一些表达差异是投射神经元亚群特有的；以及3)分子标记显示 精神分裂症受试者的表达变化出现在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，我们将比较对照受试者深层3层转录和整个DLPFC收获。这将识别表现出表达丰富的基因 随后，使用相同的微阵列和激光解剖显微镜，我们将鉴定精神分裂症患者和匹配对照组之间DLPFC第三层的mRNA表达差异。在目标2中，我们将使用原位杂交来确定最有希望的表达变化的细胞定位，并确定显示投射神经元亚群中转录水平变化的标记。在AIM 3我们将通过结合对猴子DLPFC神经元的逆行追踪和使用AIM 2中验证的标记的原位杂交来确定精神分裂症患者中受影响的DLPFC锥体神经元亚群是否共享共同的投射靶点。这些研究与其他中心项目有许多概念和技术上的联系，并依赖于所有拟议核心的支持。

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.