To understand how neurons assemble to form functional circuits, it is necessary to obtain a detailed knowledge of their diversity and to define the developmental specification programs that give rise to this diversity. Invertebrates and vertebrates appear to share common developmental principles of neuronal specification in which cascades of transcription factors temporally pattern progenitors, while spatial cues modify the outcomes of this temporal patterning. Here, we highlight these conserved mechanisms and describe how they are used in distinct neural structures. We present the questions that remain for a better understanding of neuronal specification. Single-cell RNA profiling approaches will potentially shed light on these questions, allowing not only the characterization of neuronal diversity in adult brains, but also the investigation of the developmental trajectories leading to the generation and maintenance of this diversity.

中文翻译：

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空间和时间的神经元规范

要了解神经元如何组装形成功能回路，有必要详细了解它们的多样性并定义产生这种多样性的发育规范程序。无脊椎动物和脊椎动物似乎共享神经元规范的共同发育原则，其中转录因子的级联对祖细胞进行时间模式化，而空间线索则修改了这种时间模式化的结果。在这里，我们强调了这些保守的机制，并描述了它们如何在不同的神经结构中使用。我们提出了一些问题，以便更好地理解神经元规范。单细胞 RNA 分析方法可能会阐明这些问题，不仅可以表征成人大脑中的神经元多样性，