Department of Molecular Biology and Princeton Neuroscience Institute, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544, USA.
Cerebellum. 2010 Sep;9(3):264-71. doi: 10.1007/s12311-009-0139-z.
Several studies have contributed to our understanding of astrocytes, especially Bergmann glia, in the cerebellum; but, until recently, none has looked at their function in vivo. Multicell bolus loading of fluorescent calcium indicators in combination with the astrocytic marker SR101 has allowed imaging of up to hundreds of astrocytes at once in the intact cerebellum. In addition, the selective targeting of astrocytes with fluorescent calcium indicator proteins has enabled the study of their function in vivo without the confounding effects of other neuropil signals and with a resolution that surpasses multicell bolus loading and SR101 staining. The two astrocyte types of the cerebellar cortex, Bergmann glia, and velate protoplasmic astrocytes display a diverse signaling repertoire in vivo, which ranges from localized calcium elevations in subcellular processes to waves, triggered by the release of purines and mediated by purinergic receptors that span multiple processes and can involve tens of astrocytes. During locomotor behavior, even larger numbers of astrocytes display calcium increases that are driven by neuronal activity and correlate with global changes in blood flow. In this review, we give an overview of our current understanding of the function of Bergmann glia and velate protoplasmic astrocytes and the promise of the tools used to study their calcium dynamics and function in vivo.
已有多项研究增进了我们对小脑星形胶质细胞（尤其是 Bergmann 胶质细胞）的了解；但直到最近，尚无研究关注其在体内的功能。通过对荧光钙指示剂的多细胞团块加载并结合星形胶质细胞标志物 SR101，我们可以在完整小脑内同时对多达数百个星形胶质细胞进行成像。此外，通过荧光钙指示剂蛋白对星形胶质细胞的选择性靶向，我们可以在不受到其他神经丛信号干扰的情况下，对其在体内的功能进行研究，并且分辨率超过了多细胞团块加载和 SR101 染色。小脑皮质的两种星形胶质细胞类型，Bergmann 胶质细胞和软膜原浆星形胶质细胞，在体内显示出多样化的信号转导谱，其范围从亚细胞过程中的局部钙升高到由嘌呤释放触发的波，这些波由嘌呤能受体介导，跨越多个过程，可涉及数十个星形胶质细胞。在运动行为期间，更多数量的星形胶质细胞显示出由神经元活动驱动的钙增加，并且与血流的全局变化相关。在这篇综述中，我们概述了我们目前对 Bergmann 胶质细胞和软膜原浆星形胶质细胞功能的理解，以及用于研究其钙动力学和体内功能的工具的前景。
