Reactive inhibitory control is crucial for survival. Traditionally, this control in mammals was attributed solely to the hyperdirect pathway, with cortical control signals flowing unidirectionally from the subthalamic nucleus (STN) to basal ganglia output regions. Yet recent findings have put this model into question, suggesting that the STN is assisted in stopping actions through ascending control signals to the striatum mediated by the external globus pallidus (GPe). Here, we investigate this suggestion by harnessing a biologically constrained spiking model of the cortico-basal ganglia-thalamic (CBGT) circuit that includes pallidostriatal pathways originating from arkypallidal neurons. Through a series of experiments probing the interaction between three critical inhibitory nodes (the STN, arkypallidal cells, and indirect pathway spiny projection neurons), we find that the GPe acts as a critical mediator of both ascending and descending inhibitory signals in the CBGT circuit. In particular, pallidostriatal pathways regulate this process by weakening the direct pathway dominance of the evidence accumulation process driving decisions, which increases the relative suppressive influence of the indirect pathway on basal ganglia output. These findings delineate how pallidostriatal pathways can facilitate action cancellation by managing the bidirectional flow of information within CBGT circuits.

中文翻译：

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苍白球外侧的 Arkypallidal 神经元可以通过改变纹状体中的竞争来介导抑制控制


反应性抑制控制对生存至关重要。传统上，哺乳动物的这种控制完全归因于超直接通路，皮质控制信号从丘脑底核 （STN） 单向流向基底神经节输出区域。然而，最近的研究结果使这一模型受到质疑，表明 STN 通过苍白球外球 （GPe） 介导的向纹状体的上升控制信号来协助停止动作。在这里，我们通过利用皮质-基底神经节-丘脑 （CBGT） 回路的生物学限制尖峰模型来研究这一建议，该模型包括起源于方舟神经元的苍皮纹状体通路。通过一系列实验探索三个关键抑制节点 （STN、arkypallidal 细胞和间接途径棘突投射神经元） 之间的相互作用，我们发现 GPe 在 CBGT 回路中充当上行和下行抑制信号的关键介质。特别是，苍纹状体通路通过削弱证据积累过程驱动决策的直接途径主导地位来调节这一过程，这增加了间接途径对基底神经节输出的相对抑制作用。这些发现描述了苍白纹状体通路如何通过管理 CBGT 回路内的信息双向流动来促进动作取消。