Bestrophin-1 (Best1) is a calcium-activated anion channel identified from retinal pigment epithelium where human mutations are associated with Best's macular degeneration. Best1 is known to be expressed in a variety of tissues including the brain, and is thought to be involved in many physiological processes. This review focuses on the current state of knowledge on aspects of expression and function of Best1 in the brain. Best1 protein is observed in cortical and hippocampal astrocytes, in cerebellar Bergmann glia and lamellar astrocytes, in thalamic reticular neurons, in meninges and in the epithelial cells of the choroid plexus. The most prominent feature of Best1 is its significant permeability to glutamate and GABA in addition to chloride ions because glutamate and GABA are important transmitters in the brain. Under physiological conditions, both Best1-mediated glutamate release and tonic GABA release from astrocytes modulate neuronal excitability, synaptic transmission and synaptic plasticity. Under pathological conditions such as neuroinflammation and neurodegeneration, reactive astrocytes phenotypically switch from GABA-negative to GABA-producing and redistribute Best1 from the perisynaptic microdomains to the soma and processes to tonically release GABA via Best1. This implicates that tonic GABA release from reactive astrocyte via redistributed Best1 is a common phenomenon that occur in various pathological conditions with astrogliosis such as traumatic brain injury, neuroinflammation, neurodegeneration, and hypoxic and ischemic insults. These properties of Best1, including the permeation and release of glutamate and GABA and its redistribution in reactive astrocytes, promise us exciting discoveries of novel brain functions to be uncovered in the future.

中文翻译：

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Bestrophin-1（Best1）通道在大脑中的分布和功能。

Bestrophin-1（Best1）是从视网膜色素上皮中识别出的钙激活阴离子通道，其中人类突变与Best的黄斑变性有关。Best1已知在包括大脑在内的各种组织中表达，并且被认为与许多生理过程有关。这项审查侧重于关于Best1在大脑中的表达和功能方面的知识的现状。在皮质和海马星形胶质细胞，小脑Bergmann胶质细胞和层状星形胶质细胞，丘脑网状神经元，脑膜和脉络丛上皮细胞中观察到Best1蛋白。Best1的最突出特征是其对氯离子和谷氨酸和GABA的显着渗透性，因为谷氨酸和GABA是大脑中重要的递质。在生理条件下，Best1介导的谷氨酸释放和滋补GABA从星形胶质细胞释放均调节神经元兴奋性，突触传递和突触可塑性。在神经炎症和神经退行性病变等病理条件下，反应性星形胶质细胞从GABA阴性表型转换为GABA产生型，并将Best1从突触周围微结构域重新分配至躯体，并通过Best1通过声波释放GABA。这暗示补剂GABA通过重新分布的Best1从反应性星形胶质细胞释放是一种常见现象，它发生在各种星形胶质增生症的病理情况下，例如脑外伤，神经炎症，神经变性，缺氧和缺血性损伤。Best1的这些属性，