Schwarz Jaclyn M
Department of Psychological and Brain Sciences, University of Delaware;
J Vis Exp. 2015 May 28(99):e52537. doi: 10.3791/52537.
The brain is comprised of four primary cell types including neurons, astrocytes, microglia and oligodendrocytes. Though they are not the most abundant cell type in the brain, neurons are the most widely studied of these cell types given their direct role in impacting behaviors. Other cell types in the brain also impact neuronal function and behavior via the signaling molecules they produce. Neuroscientists must understand the interactions between the cell types in the brain to better understand how these interactions impact neural function and disease. To date, the most common method of analyzing protein or gene expression utilizes the homogenization of whole tissue samples, usually with blood, and without regard for cell type. This approach is an informative approach for examining general changes in gene or protein expression that may influence neural function and behavior; however, this method of analysis does not lend itself to a greater understanding of cell-type-specific gene expression and the effect of cell-to-cell communication on neural function. Analysis of behavioral epigenetics has been an area of growing focus which examines how modifications of the deoxyribonucleic acid (DNA) structure impact long-term gene expression and behavior; however, this information may only be relevant if analyzed in a cell-type-specific manner given the differential lineage and thus epigenetic markers that may be present on certain genes of individual neural cell types. The Fluorescence Activated Cell Sorting (FACS) technique described below provides a simple and effective way to isolate individual neural cells for the subsequent analysis of gene expression, protein expression, or epigenetic modifications of DNA. This technique can also be modified to isolate more specific neural cell types in the brain for subsequent cell-type-specific analysis.
大脑由四种主要细胞类型组成，包括神经元、星形胶质细胞、小胶质细胞和少突胶质细胞。尽管神经元并非大脑中数量最多的细胞类型，但鉴于它们在影响行为方面的直接作用，是这些细胞类型中研究最为广泛的。大脑中的其他细胞类型也通过它们产生的信号分子影响神经元功能和行为。神经科学家必须了解大脑中细胞类型之间的相互作用，以便更好地理解这些相互作用如何影响神经功能和疾病。迄今为止，分析蛋白质或基因表达最常用的方法是利用全组织样本的匀浆，通常是与血液一起，且不考虑细胞类型。这种方法对于检查可能影响神经功能和行为的基因或蛋白质表达的一般变化是一种有用的方法；然而，这种分析方法并不有助于更深入地理解细胞类型特异性基因表达以及细胞间通讯对神经功能的影响。行为表观遗传学分析一直是一个日益受到关注的领域，它研究脱氧核糖核酸（DNA）结构的修饰如何影响长期基因表达和行为；然而，鉴于不同的谱系以及因此可能存在于个别神经细胞类型某些基因上的表观遗传标记，只有以细胞类型特异性的方式进行分析，这些信息才可能相关。下面描述的荧光激活细胞分选（FACS）技术提供了一种简单有效的方法来分离单个神经细胞，以便随后分析基因表达、蛋白质表达或DNA的表观遗传修饰。该技术还可以进行改进，以分离大脑中更特定的神经细胞类型，用于随后的细胞类型特异性分析。
