Yao Mei, Tudi Ayizuohere, Jiang Tao, An Xu, Jia Xueyan, Li Anan, Huang Z Josh, Gong Hui, Li Xiangning, Luo Qingming
Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China.
Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, Chinese Academy of Medical Sciences, HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China.
Research (Wash D C). 2024 Oct 7;7:0470. doi: 10.34133/research.0470. eCollection 2024.
The sensorimotor cortex participates in diverse functions with different reciprocally connected subregions and projection-defined pyramidal neuron types therein, while the fundamental organizational logic of its circuit elements at the single-cell level is still largely unclear. Here, using mouse Cre driver lines and high-resolution whole-brain imaging to selectively trace the axons and dendrites of cortical pyramidal tract (PT) and intratelencephalic (IT) neurons, we reconstructed the complete morphology of 1,023 pyramidal neurons and generated a projectome of 6 subregions within the sensorimotor cortex. Our morphological data revealed substantial hierarchical and layer differences in the axonal innervation patterns of pyramidal neurons. We found that neurons located in the medial motor cortex had more diverse projection patterns than those in the lateral motor and sensory cortices. The morphological characteristics of IT neurons in layer 5 were more complex than those in layer 2/3. Furthermore, the soma location and morphological characteristics of individual neurons exhibited topographic correspondence. Different subregions and layers were composed of different proportions of projection subtypes that innervate downstream areas differentially. While the axonal terminals of PT neuronal population in each cortical subregion were distributed in specific subdomains of the superior colliculus (SC) and zona incerta (ZI), single neurons selectively innervated a combination of these projection targets. Overall, our data provide a comprehensive list of projection types of pyramidal neurons in the sensorimotor cortex and begin to unveil the organizational principle of these projection types in different subregions and layers.
感觉运动皮层通过不同的相互连接的亚区域和其中由投射定义的锥体神经元类型参与多种功能，而其在单细胞水平上的电路元件的基本组织逻辑在很大程度上仍不清楚。在这里，我们使用小鼠Cre驱动系和高分辨率全脑成像来选择性地追踪皮质锥体束（PT）和脑内（IT）神经元的轴突和树突，重建了1023个锥体神经元的完整形态，并生成了感觉运动皮层内6个亚区域的投射图谱。我们的形态学数据揭示了锥体神经元轴突支配模式在层次和层间存在显著差异。我们发现，位于内侧运动皮层的神经元比外侧运动和感觉皮层的神经元具有更多样化的投射模式。第5层IT神经元的形态特征比第2/3层的更复杂。此外，单个神经元的胞体位置和形态特征表现出地形对应关系。不同的亚区域和层由不同比例的投射亚型组成，这些亚型对下游区域的支配方式不同。虽然每个皮质亚区域的PT神经元群体的轴突终末分布在中脑上丘（SC）和未定带（ZI）的特定子域中，但单个神经元选择性地支配这些投射靶点的组合。总体而言，我们的数据提供了感觉运动皮层中锥体神经元投射类型的全面列表，并开始揭示这些投射类型在不同亚区域和层中的组织原则。
