Cellular Density and Morphology in the Autistic Temporal Human Cerebral Cortex

描述(申请人提供)：自闭症患者表现出认知功能的改变，这在脑电记录中显示为大脑皮层兴奋和抑制的失衡。不平衡的兴奋/抑制可能是大脑结构和功能的多种改变的结果，例如自闭症大脑皮层锥体神经元和中间神经元的比率改变。参与神经传递的非神经细胞类型(如少突胶质细胞或星形胶质细胞)的数量改变，和/或大脑皮层中神经元树突和树突棘的形态或密度改变，也可能导致不平衡的兴奋/抑制。目前，关于人类自闭症大脑皮质中特定细胞类型的相对数量的现有数据是不够的，关于人类自闭症大脑皮层神经元形态的数据也是如此。已发表研究的数量很少，已发表研究中包含的案例数量很少，用于分析的案例也是不同的。充分了解自闭症在人脑中的细胞基础对于建立基本的潜在机制至关重要，这些基本机制反过来将导致治疗干预。本项目将分析21例自闭症尸检人脑(诊断为自闭症，而不是其他自闭症谱系障碍)的颞叶和18名对照人脑的颞叶，并调查：1)使用无偏见的体视学细胞定量方法，自闭症患者和对照组的颞叶皮质中总神经元、锥体神经元和神经元间亚型的密度。2)用无偏倚的体视学方法比较自闭症患者和对照组颞叶皮质中神经胶质细胞、星形胶质细胞和少突胶质细胞的密度。细胞分类将基于尼氏染色切片中的细胞形态，以及免疫组织化学实验中的细胞标志物表达。3)自闭症患者和对照组大脑颞叶的树突长度、树突分支和棘突密度。我们将使用高尔基法、NeuroLucida法和Scholl法对神经元进行染色，以确定锥体神经元和中间神经元的树突总长度、树突分支总数和棘突密度。我们将根据受试者的临床病史对病例进行分类，包括年龄、癫痫发作或智力低下的存在以及社交、交流和重复行为的水平。我们将在统计上比较自闭症患者和对照组在临床类别中的颞叶皮质密度。充分了解自闭症在人脑中的细胞基础对于建立潜在的机制至关重要，这些机制反过来可能产生新的治疗干预措施。从该项目获得的数据也将作为未来专注于神经病理学和自闭症大脑兴奋/抑制失衡的研究的基础。

DESCRIPTION (provided by applicant): Patients with autism exhibit altered cognitive function that is revealed in EEG recordings as an imbalance of excitation to inhibition in the cerebral cortex. Imbalanced excitation / inhibition could be the product of multiple alterations of brain structure and function, such as an altered ratio of pyramidal neurons to interneurons in the autistic cerebral cortex. Imbalanced excitation / inhibition could also be produced by an alteration in the number of non-neuronal cell types (such as oligodendrocytes or astrocytes) that participate in neurotransmission; and / or by altered morphology or density of neuronal dendrites and dendritic spines in the cerebral cortex. Existing data on the relative number of specific cell types in the cerebral cortex of human autistic brains is at this point insufficient, as is data on the morphology of neurons in the human autistic cerebral cortex. The number of published studies is scarce, the number of cases included in the published studies is small, and the cases used for analysis is heterogeneous. A full understanding of the cellular basis of autism in human brain is essential for establishing the basic underlying mechanisms that, in turn, will result in therapeutic interventions. This project will analyze the temporal lobe of 21 autistic postmortem human brains (diagnosed as autistic, not as other autism spectrum disorders) and the temporal lobe of 18 control postmortem human brains, and investigate: 1) Density of total neurons, pyramidal neurons, and interneuronal subtypes in the autistic versus control temporal cortex using unbiased stereological methods for cell quantification. 2) Density of total glial cells, astrocytes, and oligodendrocytes in the autistic versus control temporal cortex using unbiased stereological methods. Cellular classification will be based on cellular morphology in Nissl stained sections, and on cellular marker expression in immunohistochemical experiments. 3) Dendrite length, dendritic branching, and spine density in the temporal lobe of autistic and control brains. We will stain neurons using the Golgi method, Neurolucida and the Scholl method to determine total dendritic length, total number of dendritic branches and spine density in pyramidal neurons and interneurons. We will classify our cases based on the subject's clinical history, including age, the presence of seizures or mental retardation, and the levels of social, communicative, and repetitive behaviors. We will statistically compare densities in the autistic versus control temporal cortex within clinical categories. A full understanding of the cellular basis of autism in the human brain is essential for establishing underlying mechanisms that in turn could yield new therapeutic interventions. The data obtained from this project will also serve as the basis for future studies focusing on the neuropathology and the imbalance excitation / inhibition of the autistic brain.