The caudal forelimb area (CFA) of the mouse cortex is essential in many forelimb movements, and diverse types of GABAergic interneuron in the CFA are distinct in the mediation of cortical inhibition in motor information processing. However, their long-range inputs remain unclear. In the present study, we combined the monosynaptic rabies virus system with Cre driver mouse lines to generate a whole-brain map of the inputs to three major inhibitory interneuron types in the CFA. We discovered that each type was innervated by the same upstream areas, but there were quantitative differences in the inputs from the cortex, thalamus, and pallidum. Comparing the locations of the interneurons in two sub-regions of the CFA, we discovered that their long-range inputs were remarkably different in distribution and proportion. This whole-brain mapping indicates the existence of parallel pathway organization in the forelimb subnetwork and provides insight into the inhibitory processes in forelimb movement to reveal the structural architecture underlying the functions of the CFA.

中文翻译：

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小鼠尾前肢区域中GABA能神经元的远程输入的全脑图。

在许多前肢运动中，小鼠皮质的尾部前肢区域（CFA）是必不可少的，并且CFA中GABA能级中间神经元的不同类型在运动信息处理中的皮质抑制作用的介导方面是截然不同的。但是，它们的远程输入仍不清楚。在本研究中，我们结合了单突触狂犬病病毒系统和Cre驱动程序小鼠系，以生成CFA中三种主要抑制性中间神经元输入的全脑图。我们发现每种类型都由相同的上游区域支配，但是皮质，丘脑和苍白球的输入存在数量差异。比较CFA的两个子区域中的中间神经元的位置，我们发现它们的远程输入在分布和比例上都明显不同。