美国艾伦脑科学研究所Hongkui Zeng和Shenqin Yao共同合作，近期取得重要工作进展。他们研究开发了小鼠视觉皮层神经元类别的全脑单突触输入连接组。相关研究成果2022年12月22日在线发表于《自然—神经科学》杂志上。

据介绍，识别神经元之间的结构连接是理解大脑功能的先决条件。

研究人员开发了一个管道，使用优化的狂犬病追踪系统，系统性地将全脑单突触输入连接映射到遗传定义的神经元群体中。研究人员使用小鼠视觉皮层作为范例系统，揭示了其突触前连接体的定量靶标特异性、层特异性和细胞类特异性差异。逆行连接表明腹侧和背侧视觉流的存在，并进一步揭示了由不同高级视觉区域介导的拓扑组织和连续变化的子网络。视觉皮层层次结构可以从皮层内前馈和反馈通路中导出，这些通路由上层和下层输入神经元介导。研究人员还确定了第6层神经元在介导半球间相互连接中的新作用。

这项研究扩展了人们对视觉系统连接体的了解，并证明了管道可以放大，以分析小鼠大脑中不同细胞群的连接。

附：英文原文

Title: A whole-brain monosynaptic input connectome to neuron classes in mouse visual cortex

Author: Yao, Shenqin, Wang, Quanxin, Hirokawa, Karla E., Ouellette, Benjamin, Ahmed, Ruweida, Bomben, Jasmin, Brouner, Krissy, Casal, Linzy, Caldejon, Shiella, Cho, Andy, Dotson, Nadezhda I., Daigle, Tanya L., Egdorf, Tom, Enstrom, Rachel, Gary, Amanda, Gelfand, Emily, Gorham, Melissa, Griffin, Fiona, Gu, Hong, Hancock, Nicole, Howard, Robert, Kuan, Leonard, Lambert, Sophie, Lee, Eric Kenji, Luviano, Jennifer, Mace, Kyla, Maxwell, Michelle, Mortrud, Marty T., Naeemi, Maitham, Nayan, Chelsea, Ngo, Nhan-Kiet, Nguyen, Thuyanh, North, Kat, Ransford, Shea, Ruiz, Augustin, Seid, Sam, Swapp, Jackie, Taormina, Michael J., Wakeman, Wayne, Zhou, Thomas, Nicovich, Philip R., Williford, Ali, Potekhina, Lydia, McGraw, Medea, Ng, Lydia, Groblewski, Peter A., Tasic, Bosiljka, Mihalas, Stefan, Harris, Julie A., Cetin, Ali, Zeng, Hongkui

Issue&Volume: 2022-12-22

Abstract: Identification of structural connections between neurons is a prerequisite to understanding brain function. Here we developed a pipeline to systematically map brain-wide monosynaptic input connections to genetically defined neuronal populations using an optimized rabies tracing system. We used mouse visual cortex as the exemplar system and revealed quantitative target-specific, layer-specific and cell-class-specific differences in its presynaptic connectomes. The retrograde connectivity indicates the presence of ventral and dorsal visual streams and further reveals topographically organized and continuously varying subnetworks mediated by different higher visual areas. The visual cortex hierarchy can be derived from intracortical feedforward and feedback pathways mediated by upper-layer and lower-layer input neurons. We also identify a new role for layer 6 neurons in mediating reciprocal interhemispheric connections. This study expands our knowledge of the visual system connectomes and demonstrates that the pipeline can be scaled up to dissect connectivity of different cell populations across the mouse brain.

DOI: 10.1038/s41593-022-01219-x

Source: https://www.nature.com/articles/s41593-022-01219-x