Human Post-Mortem Pathology (in-situ Hyb etc.)

人类死后病理学（原位杂交等）

• 批准号: 7478381
• 负责人: GRAZYNA RAJKOWSKA
• 金额: $ 24.18万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7478381
• 关键词: 3-Dimensional; Antidepressive Agents; Astrocytes; Autopsy; Axon; Cell Count; Cells; Complex; D Cells; Depressed mood; Etiology; Functional disorder; Glutamates; Homeostasis; Human; Immunohistochemistry; In Situ; In Situ Hybridization; Interneurons; Lead; Life; Localized; Major Depressive Disorder; Mental Depression; Messenger RNA; Neuroglia; Neurons; Numbers; Pathology; Prefrontal Cortex; Presynaptic Receptors; Proteins; Role; Selective Serotonin Reuptake Inhibitor; Serotonin; System; Techniques; Testing; Tissue Sample; age related; calbindin; cell type; density; depressive symptoms; extracellular; gamma-Aminobutyric Acid; hippocampal pyramidal neuron; nerve supply; neuroimaging; neurotoxic; novel; postsynaptic; prevent; receptor; serotonin receptor; serotonin transporter; size

Major depressive disorder (MDD) is characterized by reductions in the density and size of neuronal and glial cells in prefrontal cortex. We find these cellular changes to be age-dependent as younger depressed show prominent reductions in the density of glial cells (astrocytes), whereas older depressed have marked reductions in the density of pyramidal (presumably glutamate) neurons and calbindin-immunoreactive interneurons (mostly co-localizing GABA). Since, astrocytes regulate concentration of glutamate, an excess of which is neurotoxic, we propose that an early deficit in astrocytes in MDD could lead to an increase in the extracellular concentration of glutamate and to a reduction in pyramidal and GABA neurons later in life. Hence, there may be imbalances in GABA/glutamate homeostasis that are consistent with neuroimaging studies revealing changes in levels of GABA and glutamate in MDD which are reversible with antidepressant (SSRI) treatment. Cortical neurons are regulated in complex ways by serotonin acting (at least) at serotonin- 1A and -2A receptors located on these neurons and astrocytes. Pathology in ascending serotoninergic axons and postsynaptic receptors may be related to the activity, number and size of glutamate and/or GABA neurons and astrocytes in MDD. To date, there have been no studies on the expression or localization of serotonin receptors on specific cortical cell types in depression. The overall hypothesis is that in depression there will be age-dependent reductions in the density of astrocytes, glutamate pyramidal neurons and GABA interneurons, and that the expression of regulatory serotonin-1A and -2A receptors on these cells will be altered. These cell reductions will also be correlated with an age-related loss of serotonin innervation in prefrontal layers. To test these hypotheses, we will directly identify and quantify the packing density of astrocytes and glutamate and GABA neurons expressing mRNA for specific proteins (Aim 1). Moreover, we will assess the integrity of the serotonin system regulators (postsynaptic receptors and presynaptic axons) of prefrontal cells by estimating the proportion of cell types expressing mRNA for serotonin-1 A and -2A receptors (Aim 2), and the density of serotonin axons expressing the serotonin transporter (Aim 3). Double in situ hybridization, immunohistochemistry and 3-D cell counting techniques will be used in the same postmortem tissue sampled from the prefrontal cortex of younger and older subjects with MDD and non-depressed controls as used in our cell counting studies. This project will identify the cellular substrates of glutamate, GABA and serotonin interactions in the cortex and their potential role in the etiology, pathophysiology and age-related progression of depression. It may also reveal novel targets for preventing depressive illness and better antidepressant drug treatment.

重度抑郁症 (MDD) 的特点是神经元和胶质细胞的密度和大小减少 前额皮质中的细胞。我们发现这些细胞变化与年龄有关，正如年轻的抑郁症患者所表现的那样 神经胶质细胞（星形胶质细胞）密度显着降低，而老年人抑郁症则明显减少 锥体（可能是谷氨酸）神经元和钙结合蛋白免疫反应性密度降低 中间神经元（主要是共定位 GABA）。由于星形胶质细胞调节谷氨酸的浓度，过量的 其中具有神经毒性，我们认为 MDD 中星形胶质细胞的早期缺陷可能导致 细胞外谷氨酸浓度以及晚年锥体神经元和 GABA 神经元的减少。 因此，GABA/谷氨酸稳态可能存在不平衡，这与神经影像学一致 研究表明 MDD 中 GABA 和谷氨酸水平的变化可通过抗抑郁药物逆转 （SSRI）治疗。皮质神经元通过血清素（至少）以复杂的方式调节 1A 和-2A 受体位于这些神经元和星形胶质细胞上。血清素能上升的病理学 轴突和突触后受体可能与谷氨酸和/或 GABA 的活性、数量和大小有关 MDD 中的神经元和星形胶质细胞。迄今为止，还没有关于其表达或定位的研究。 抑郁症中特定皮层细胞类型的血清素受体。 总体假设是，在抑郁症中，大脑的密度会随着年龄的增长而降低。 星形胶质细胞、谷氨酸锥体神经元和 GABA 中间神经元，并且调节性表达 这些细胞上的血清素-1A 和-2A 受体将发生改变。这些细胞减少也将相关 与年龄相关的前额叶层血清素神经支配丧失。为了检验这些假设，我们将 直接识别和量化星形胶质细胞以及表达谷氨酸和 GABA 神经元的堆积密度 特定蛋白质的 mRNA（目标 1）。此外，我们将评估血清素系统调节器的完整性 通过估计细胞类型的比例来估计前额细胞（突触后受体和突触前轴突） 表达 5-羟色胺-1 A 和 -2A 受体的 mRNA（目标 2），以及 5-羟色胺轴突的密度 表达血清素转运蛋白（目标 3）。双原位杂交、免疫组织化学和 3-D 细胞计数技术将用于从前额皮质取样的相同死后组织。 患有 MDD 的年轻和年长受试者以及我们细胞计数研究中使用的非抑郁对照。 该项目将确定谷氨酸、GABA 和血清素相互作用的细胞底物 皮质及其在抑郁症的病因学、病理生理学和年龄相关进展中的潜在作用。它 还可能揭示预防抑郁症和更好的抗抑郁药物治疗的新目标。