Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Laboratory for Neuro- & Psychophysiology, Department of Neurosciences, KU Leuven, O&N2 Campus Gasthuisberg, Herestraat 49, bus 1021, 3000 Leuven, Belgium.
Department of Neurobiology, University of Pittsburgh, PA 15261, USA.
Neuroimage. 2021 Feb 15;227:117647. doi: 10.1016/j.neuroimage.2020.117647. Epub 2020 Dec 15.
Neurophysiological and anatomical data suggest the existence of several functionally distinct regions in the lower arcuate sulcus and adjacent postarcuate convexity of the macaque monkey. Ventral premotor F5c lies on the postarcuate convexity and consists of a dorsal hand-related and ventral mouth-related field. The posterior bank of the lower arcuate contains two additional premotor F5 subfields at different anterior-posterior levels, F5a and F5p. Anterior to F5a, area 44 has been described as a dysgranular zone occupying the deepest part of the fundus of the inferior arcuate. Finally, area GrFO occupies the most rostral portion of the fundus and posterior bank of inferior arcuate and extends ventrally onto the frontal operculum. Recently, data-driven exploratory approaches using resting-state fMRI data have been suggested as a promising non-invasive method for examining the functional organization of the primate brain. Here, we examined to what extent partitioning schemes derived from data-driven clustering analysis of resting-state fMRI data correspond with the proposed organization of the fundus and posterior bank of the macaque arcuate sulcus, as suggested by invasive architectonical, connectional and functional investigations. Using a hierarchical clustering analysis, we could retrieve clusters corresponding to the dorsal and ventral portions of F5c on the postarcuate convexity, F5a and F5p at different antero-posterior locations on the posterior bank of the lower arcuate, area 44 in the fundus, as well as part of area GrFO in the most anterior portion of the fundus. Additionally, each of these clusters displayed distinct whole-brain functional connectivity, in line with previous anatomical tracer and seed-based functional connectivity investigations of F5/44 subdivisions. Overall, our data suggests that hierarchical clustering analysis of resting-state fMRI data can retrieve a fine-grained level of cortical organization that resembles detailed parcellation schemes derived from invasive functional and anatomical investigations.
神经生理学和解剖学数据表明，在猕猴的下弓状沟和相邻的后弓状凸面存在几个功能上不同的区域。腹侧运动前区 F5c 位于后弓状凸面，由一个背侧手部相关区和一个腹侧口部相关区组成。下弓状沟后缘包含另外两个位于不同前后水平的前运动区 F5 子区，即 F5a 和 F5p。F5a 前方，区域 44 被描述为一个颗粒减少区，占据下弓状沟底部的最深部分。最后，区域 GrFO 占据下弓状沟底部和后缘的最前部分，并向额侧盖上延伸。最近，使用静息态 fMRI 数据的基于数据的探索性方法被认为是一种有前途的非侵入性方法，可用于检查灵长类动物大脑的功能组织。在这里，我们研究了基于静息态 fMRI 数据的聚类分析得出的分区方案在多大程度上与下弓状沟的后缘和底部的建议组织相对应，正如侵袭性建筑、连接和功能研究所建议的那样。使用层次聚类分析，我们可以检索到与后弓状凸面上 F5c 的背侧和腹侧部分、下弓状沟后缘上不同前后位置的 F5a 和 F5p、底部的 44 区以及底部最前部的 GrFO 部分相对应的聚类。此外，这些聚类中的每一个都显示出与之前关于 F5/44 细分的解剖示踪剂和基于种子的功能连接研究一致的独特全脑功能连接。总的来说，我们的数据表明，静息态 fMRI 数据的层次聚类分析可以检索到类似于来自侵袭性功能和解剖研究的详细分割方案的精细皮质组织。
