Defining Astrocyte Heterogenity Across the Brainstem Respiratory Circuit

项目摘要 皮质星形胶质细胞具有遗传多样性，然而，其生理相关性还远未被理解 因为功能离散的星形胶质细胞亚型对整个动物行为的贡献在很大程度上是未知的。 最令人信服的证据支持星形胶质细胞可能具有特殊的生理功能， 作用是在脑干水平，其中星形胶质细胞亚群有助于CO2/H+依赖性驱动， 呼吸（呼吸化学感受）和吸气节律产生。因此，我们将使用呼吸 电路作为一个模型系统，以确定独特的基因配置文件的功能定义的子集的星形胶质细胞。我们 将使用RNA-seq对分离自以下的所有细胞类型中的转录本表达进行无偏评估： 化学敏感区、吸气节律产生区和非呼吸性脑干和皮层 地区该分析将集中于基于细胞类型表达鉴定为星形胶质细胞的细胞群。 特定的标记。为了将基因表达与功能相关联，我们将使用电生理学或Ca 2+成像， 用于在功能上鉴定来自每个区域的切片中的单个星形胶质细胞以用于随后收获的技术， 针对每个星形胶质细胞亚群表达的基因的靶向qPCR。拟议的工作将使 开发工具来研究星形胶质细胞的离散亚群对呼吸行为的贡献。 此外，由于星形胶质细胞CO2/H+化学感受性的破坏有助于某些人的呼吸紊乱， 疾病（例如Rett综合征），选择性靶向CO2/H+敏感性星形胶质细胞的能力将是一种治疗方法。 有吸引力的策略来治疗与这种情况相关的呼吸障碍。

PROJECT SUMMARY Cortical astrocytes are genetically diverse; however, the physiological relevance of this is far from understood because contributions of functionally discrete astrocyte subtypes to whole animal behavior is largely unknown. The most compelling evidence supporting the possibility that astrocytes may have specialized physiological roles is at the level of the brainstem where subsets of astrocytes contribute to the CO2/H+-dependent drive to breathe (respiratory chemoreception) and inspiratory rhythm generation. Therefore, we will use the respiratory circuit as a model system to identify unique genetic profiles of functionally defined subsets of astrocytes. We will use RNA-seq to perform an unbiased evaluation of transcript expression in all cell types isolated from chemosensitive regions, the inspiratory rhythm generating region and non-respiratory brainstem and cortical regions. This analysis will focus on cell populations identified as astrocytes based on expression of cell type specific markers. To correlate gene expression with function, we will use electrophysiological or Ca2+ imaging techniques to functionally identify individual astrocytes in slices from each region for subsequent harvest and targeted qPCR for genes expressed by each astrocyte subpopulation. The proposed work will enable development of tools to study contributions of discrete subpopulations of astrocyte to respiratory behavior. Also, since disruption of astrocyte CO2/H+ chemoreception contributes to disordered breathing in certain diseases (e.g. Rett syndrome), the ability to selectively target CO2/H+-sensitive astrocytes would be an attractive strategy for treating disordered breathing associated with this condition.