美国圣路易斯华盛顿大学Nico U. F. Dosenbach等研究人员合作发现，运动皮层中的躯体认知行动网络与效应区交替出现。相关论文于2023年4月19日在线发表在《自然》杂志上。

通过使用精确的功能磁共振成像（fMRI）方法，研究人员发现经典的homunculus被具有不同连接性、结构和功能的区域打断，与效应器特定（脚、手和嘴）区域交替出现。这些效应器间区域表现出皮层厚度的减少和彼此间强大的功能连接，以及对行动和生理控制、唤醒、错误和疼痛至关重要的齿状核网络（CON）。在三个最大的fMRI数据集中验证了这种与行动控制相关的和运动效应区的相互连接。猕猴和幼儿（新生儿、婴儿和儿童）的精确fMRI显示了跨物种的同源性和效应器间系统的发育前兆。一组运动和行动fMRI任务记录了同心的效应器体表，由CON连接的效应器间区域分开。效应器间缺乏运动特异性，在行动规划（手和脚的协调）和身体轴向运动（如腹部或眉毛）中共同激活。

这些结果，加上以前的研究表明刺激诱发的复杂行动和与内部器官的连接，如肾上腺髓质，表明M1是由一个全身行动规划的系统，即躯体-认知行动网络（SCAN）。在M1中，两个平行的系统交织在一起，形成一个整合-隔离模式：效应器特定区域（脚、手和嘴）用于隔离精细运动控制，SCAN用于整合目标、生理学和身体运动。

据介绍，运动皮层（M1）被认为形成了一个连续的somatotopic homunculus，从脚到脸的表征延伸到中央前回，尽管有证据表明有同心的功能区和复杂行动的地图。

附：英文原文

Title: A somato-cognitive action network alternates with effector regions in motor cortex

Author: Gordon, Evan M., Chauvin, Roselyne J., Van, Andrew N., Rajesh, Aishwarya, Nielsen, Ashley, Newbold, Dillan J., Lynch, Charles J., Seider, Nicole A., Krimmel, Samuel R., Scheidter, Kristen M., Monk, Julia, Miller, Ryland L., Metoki, Athanasia, Montez, David F., Zheng, Annie, Elbau, Immanuel, Madison, Thomas, Nishino, Tomoyuki, Myers, Michael J., Kaplan, Sydney, Badke DAndrea, Carolina, Demeter, Damion V., Feigelis, Matthew, Ramirez, Julian S. B., Xu, Ting, Barch, Deanna M., Smyser, Christopher D., Rogers, Cynthia E., Zimmermann, Jan, Botteron, Kelly N., Pruett, John R., Willie, Jon T., Brunner, Peter, Shimony, Joshua S., Kay, Benjamin P., Marek, Scott, Norris, Scott A., Gratton, Caterina, Sylvester, Chad M., Power, Jonathan D., Liston, Conor, Greene, Deanna J., Roland, Jarod L., Petersen, Steven E., Raichle, Marcus E., Laumann, Timothy O., Fair, Damien A., Dosenbach, Nico U. F.

Issue&Volume: 2023-04-19

Abstract: Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representations1,2, despite evidence for concentric functional zones3 and maps of complex actions4. Here, using precision functional magnetic resonance imaging (fMRI) methods, we find that the classic homunculus is interrupted by regions with distinct connectivity, structure and function, alternating with effector-specific (foot, hand and mouth) areas. These inter-effector regions exhibit decreased cortical thickness and strong functional connectivity to each other, as well as to the cingulo-opercular network (CON), critical for action5 and physiological control6, arousal7, errors8 and pain9. This interdigitation of action control-linked and motor effector regions was verified in the three largest fMRI datasets. Macaque and pediatric (newborn, infant and child) precision fMRI suggested cross-species homologues and developmental precursors of the inter-effector system. A battery of motor and action fMRI tasks documented concentric effector somatotopies, separated by the CON-linked inter-effector regions. The inter-effectors lacked movement specificity and co-activated during action planning (coordination of hands and feet) and axial body movement (such as of the abdomen or eyebrows). These results, together with previous studies demonstrating stimulation-evoked complex actions4 and connectivity to internal organs10 such as the adrenal medulla, suggest that M1 is punctuated by a system for whole-body action planning, the somato-cognitive action network (SCAN). In M1, two parallel systems intertwine, forming an integrate–isolate pattern: effector-specific regions (foot, hand and mouth) for isolating fine motor control and the SCAN for integrating goals, physiology and body movement.

DOI: 10.1038/s41586-023-05964-2

Source: https://www.nature.com/articles/s41586-023-05964-2