中枢神经系统（CNS）中提供体内平衡的关键细胞是星形胶质细胞，它们属于神经胶质类型的高度异质性细胞，是大脑防御的重要组成部分。由于病理状况引起的星形胶质细胞重构包括反应性星形胶质细胞、星形胶质细胞萎缩和星形胶质细胞退化导致的内平衡状态改变是疾病演变的原因。这些特征是多数感染侵害的标志，由细菌、原生动物和病毒介导；它们也在全身感染中突出表现。COVID-19疫情重新关注了神经病毒，如SARS-CoV2（冠状病毒科），以及弥散性感染中的蜱媒脑炎病毒（TBEV）和寨卡病毒（ZIKV），它们在COVID-19之前导致了南美的流行病。星形胶质细胞在CNS对神经病毒感染提供关键响应。星形胶质细胞是血脑屏障的实质性部分，病毒进入CNS的位置。星形胶质细胞表现出有氧糖酵解，这是高度可塑细胞如癌细胞的代谢特征，因此适合于包括病毒粒子在内的感染因子的繁殖环境。然而，为什么星形胶质细胞在某些情况下提供的保护失效是一个未来需要研究的开放性问题。 ©2022作者。由波特兰出版社代表生化学会出版。

Key homeostasis providing cells in the central nervous system (CNS) are astrocytes, which belong to the class of cells known as atroglia, a highly heterogeneous type of neuroglia and a prominent element of the brain defence. Diseases evolve due to altered homeostatic state, associated with pathology-induced astroglia remodelling represented by reactive astrocytes, astroglial atrophy and astrodegeneration. These features are hallmarks of most infectious insults, mediated by bacteria, protozoa and viruses; they are also prominent in the systemic infection. The COVID-19 pandemic revived the focus into neurotropic viruses such as SARS-CoV2 (Coronaviridae) but also the Flaviviridae viruses including tick-borne encephalitis (TBEV) and Zika virus (ZIKV) causing the epidemic in South America prior to COVID-19. Astrocytes provide a key response to neurotropic infections in the CNS. Astrocytes form a parenchymal part of the blood-brain barrier, the site of virus entry into the CNS. Astrocytes exhibit aerobic glycolysis, a form of metabolism characteristic of highly morphologically plastic cells, like cancer cells, hence a suitable milieu for multiplication of infectious agent, including viral particles. However, why the protection afforded by astrocytes fails in some circumstances is an open question to be studied in the future.© 2022 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.