前外侧运动皮层(ALM)对于随后的正确运动至关重要,并且在预测特定的未来运动中起着至关重要的作用。ALM的不同下降途径优先参与运动中的不同角色。然而,这些不同路径的回路功能机制可能隐藏在解剖回路中。阐明这些途径的解剖输入应该为阐明这些功能机制提供一些有用的信息。这里,我们用一种逆行的跨突触狂犬病病毒系统产生,分析和比较丘脑输入的全脑图(TH)-,延髓(Med)-,上丘(SC)-,C57BL/6J小鼠脑桥核(Pons)-投射ALM神经元。确定了来自9个主要大脑区域的59个独立区域,这些区域投射到ALM的下降途径。全脑定量分析揭示了这些下降途径之间相同的全脑输入模式。通路的大部分输入来自大脑的同侧,大部分神经由皮质和TH提供。大脑的对侧也发送了稀疏的投影,但是这些很罕见,只从大脑皮层和小脑发出.然而,TH-接收的输入,Meda-,SC和Pons投射的ALM神经元具有不同的权重,可能为理解ALM明确定义的下降途径的多种功能奠定解剖学基础。我们的发现提供了解剖学信息,以帮助阐明ALM的精确连接和多种功能。
The anterior lateral motor cortex (ALM) is critical to subsequent correct movements and plays a vital role in predicting specific future movements. Different descending pathways of the ALM are preferentially involved in different roles in movements. However, the circuit function mechanisms of these different pathways may be concealed in the anatomy circuit. Clarifying the anatomy inputs of these pathways should provide some helpful information for elucidating these function mechanisms. Here, we used a retrograde trans-synaptic rabies virus to systematically generate, analyze, and compare whole brain maps of inputs to the thalamus (TH)-, medulla oblongata (Med)-, superior colliculus (SC)-, and pontine nucleus (Pons)-projecting ALM neurons in C57BL/6J mice. Fifty-nine separate regions from nine major brain areas projecting to the descending pathways of the ALM were identified. Brain-wide quantitative analyses revealed identical whole brain input patterns between these descending pathways. Most inputs to the pathways originated from the ipsilateral side of the brain, with most innervations provided by the cortex and TH. The contralateral side of the brain also sent sparse projections, but these were rare, emanating only from the cortex and cerebellum. Nevertheless, the inputs received by TH-, Med-, SC-, and Pons-projecting ALM neurons had different weights, potentially laying an anatomical foundation for understanding the diverse functions of well-defined descending pathways of the ALM. Our findings provide anatomical information to help elucidate the precise connections and diverse functions of the ALM.NEW & NOTEWORTHY Distinct descending pathways of anterior lateral motor cortex (ALM) share common inputs. These inputs are with varied weights. Most inputs were from the ipsilateral side of brain. Preferential inputs were provided by cortex and thalamus (TH).