In the mammalian cerebral cortex neurons are arranged in specific layers and form connections both within the cortex and with other brain regions, thus forming a complex mesh of specialized synaptic connections comprising distinct circuits. The correct establishment of these connections during development is crucial for the proper function of the brain. Astrocytes, a major type of glial cell, are important regulators of synapse formation and function during development. While neurogenesis precedes astrogenesis in the cortex, neuronal synapses only begin to form after astrocytes have been generated, concurrent with neuronal branching and process elaboration. Here we provide a combined overview of the developmental processes of synapse and circuit formation in the rodent cortex, emphasizing the timeline of both neuronal and astrocytic development and maturation. We further discuss the role of astrocytes at the synapse, focusing on astrocyte-synapse contact and the role of synapse-related proteins in promoting formation of distinct cortical circuits.

中文翻译：

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星形胶质细胞，神经元，突触：关于皮层回路发育的三方观点。

在哺乳动物的大脑皮层中，神经元排列在特定的层中，并在大脑皮层内和与其他大脑区域之间形成连接，从而形成了包含不同电路的专门突触连接的复杂网格。这些连接在发育过程中的正确建立对于大脑的正常功能至关重要。星形胶质细胞是神经胶质细胞的主要类型，在发育过程中是突触形成和功能的重要调节剂。虽然神经发生先于皮质的星形胶质细胞生成，但神经元突触仅在星形胶质细胞生成后才开始形成，并伴有神经元分支和过程的形成。在这里，我们提供了啮齿动物皮层中突触和回路形成的发展过程的综合概述，强调神经元和星形细胞发育和成熟的时间表。我们进一步讨论星形胶质细胞在突触中的作用，重点是星形胶质细胞与突触的接触以及突触相关蛋白在促进不同皮层回路形成中的作用。