引用

在基底神经节回路中，外苍白球(GPe)在运动控制中起重要作用。除了Foxp2+神经元和ChAT+神经元已经被确定为独特的神经元类型外，关于GPe神经元的分类几乎没有共识。其余神经元类型的特性定义很差。在这项研究中，我们利用新的小鼠系、病毒工具和分子标记来更好地定义GPe神经元亚型。我们发现Sox6代表了GPe神经元亚型的一个新的定义标记。缺乏Sox6表达的Lhx6+神经元缺乏parvalbumin和Npas1。这个结果证实了先前关于存在一个独特的Lhx6+种群的断言。来自Dbx1+谱系的神经元在GPe中同样丰富，并显示出异质性组成。重要的是，追踪实验显示Npas1+-Nkx2.1+神经元是主要的非胆碱能皮质投射神经元。换句话说，它们形成了皮层-皮层-苍白体-皮层环的苍白体-皮层臂。 Our data further show that pyramidal-tract neurons in the cortex collateralized within the GPe, forming a closed-loop system between the two brain structures. Overall, our findings reconcile some of the discrepancies that arose from differences in techniques or the reliance on preexisting tools. Although spatial distribution and electrophysiological properties of GPe neurons reaffirm the diversification of GPe subtypes, statistical analyses strongly support the notion that these neuron subtypes can be categorized under the two principal neuron classes: PV+ neurons and Npas1+ neurons.SIGNIFICANCE STATEMENT The poor understanding of the neuronal composition in the external globus pallidus (GPe) undermines our ability to interrogate its precise behavioral and disease involvements. In this study, 12 different genetic crosses were used, hundreds of neurons were electrophysiologically characterized, and >100,000 neurons were histologically- and/or anatomically-profiled. Our current study further establishes the segregation of GPe neuron classes and illustrates the complexity of GPe neurons in adult mice. Our results support the idea that Npas1+-Nkx2.1+ neurons are a distinct GPe neuron subclass. By providing a detailed analysis of the organization of the cortico-pallidal-cortical projection, our findings establish the cellular and circuit substrates that can be important for motor function and dysfunction. Copyright 2020 the authors.