Defining Astrocyte Heterogenity Across the Brainstem Respiratory Circuit

项目概要 皮质星形胶质细胞具有遗传多样性；然而，其生理相关性尚不清楚 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 其作用位于脑干水平，其中星形胶质细胞亚群负责 CO2/H 依赖性驱动 呼吸（呼吸化学感受）和吸气节律的产生。因此，我们将使用呼吸 电路作为模型系统来识别功能定义的星形胶质细胞子集的独特遗传谱。我们 将使用 RNA-seq 对从以下细胞中分离出的所有细胞类型中的转录物表达进行公正的评估 化学敏感区、吸气节律产生区和非呼吸脑干和皮质 地区。该分析将重点关注根据细胞类型的表达被识别为星形胶质细胞的细胞群 具体标记。为了将基因表达与功能相关联，我们将使用电生理学或 Ca2 成像 功能性识别每个区域切片中的单个星形胶质细胞的技术，以便随后收获和 对每个星形胶质细胞亚群表达的基因进行靶向 qPCR。拟议的工作将使 开发工具来研究星形胶质细胞离散亚群对呼吸行为的贡献。 此外，由于星形胶质细胞 CO2/H 化学感受的破坏会导致某些人的呼吸紊乱。 疾病（例如 Rett 综合征），选择性靶向 CO2/H 敏感星形胶质细胞的能力将是一种 治疗与这种情况相关的呼吸障碍的有吸引力的策略。

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.