Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn, Germany.
Cell Tissue Res. 2018 Sep;373(3):653-670. doi: 10.1007/s00441-017-2746-1. Epub 2017 Dec 4.
The contribution of glial cells to normal and impaired hippocampal function is increasingly being recognized, although important questions as to the mechanisms that these cells use for their crosstalk with neurons and capillaries are still unanswered or lead to controversy. Astrocytes in the hippocampus are morphologically variable and a single cell contacts with its processes more than 100,000 synapses. They predominantly express inward rectifier K channels and transporters serving homeostatic function but may also release gliotransmitters to modify neuronal signaling and brain circulation. Intracellular Ca transients are key events in the interaction of astrocytes with neurons and the vasculature. Hippocampal NG2 glia represent a population of cells with proliferative capacity throughout adulthood. Intriguingly, they receive direct synaptic input from pyramidal neurons and interneurons and express a multitude of ion channels and receptors. Despite in-depth knowledge about the features of these transmembrane proteins, the physiological impact of NG2 glial cells and their synaptic input remain nebulous. Because of the low abundance of oligodendrocytes in the hippocampus, limited information is available about their specific properties. Given the multitude of signaling molecules expressed by the various types of hippocampal glial cells (and because of space constraints), we focus, in this review, on those properties that are considered key for the interaction of the respective cell type with its neighborhood.
胶质细胞对海马体正常和损伤功能的贡献正日益得到认可，尽管对于这些细胞用于与神经元和毛细血管进行串扰的机制仍存在一些重要问题尚未得到解答或存在争议。海马体中的星形胶质细胞形态多样，单个细胞的突起与超过 100,000 个突触接触。它们主要表达内向整流钾通道和用于维持稳态的转运体，但也可能释放神经胶质递质来调节神经元信号传递和脑循环。细胞内 Ca 瞬变是星形胶质细胞与神经元和血管相互作用的关键事件。海马体 NG2 胶质细胞是一类在整个成年期具有增殖能力的细胞。有趣的是，它们接收来自锥体神经元和中间神经元的直接突触输入，并表达多种离子通道和受体。尽管对这些跨膜蛋白的特征有深入的了解，但 NG2 胶质细胞及其突触输入的生理影响仍然不清楚。由于海马体中少突胶质细胞的丰度较低，因此关于其特定特性的信息有限。鉴于各种类型的海马体胶质细胞表达的信号分子众多（由于篇幅限制），我们在这篇综述中重点关注那些被认为是各自细胞类型与其周围环境相互作用的关键特性。
