Fine-Grained Topography and Modularity of the Macaque Frontal Pole Cortex Revealed by Anatomical Connectivity Profiles
Bin He 1,2,3• Long Cao 2,5• Xiaoluan Xia 2,8• Baogui Zhang 2,3• Dan Zhang 10•Bo You 1• Lingzhong Fan 2,3,4,7• Tianzi Jiang 2,3,4,5,6,7,9
1 School of Mechanical and Power Engineering, Harbin University of Science and Technology, Harbin 150080, China
2 Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
3 National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences (CAS), Beijing 100190, China
4 Center for Excellence in Brain Science and Intelligence Technology, Institute of Automation, CAS, Beijing 100190, China
5 Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
6 The Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
7 University of CAS, Beijing 100049, China
8 College of Information and Computer, Taiyuan University of Technology, Taiyuan 030600, China
9 Chinese Institute for Brain Research, Beijing 102206, China
10 Core Facility, Center of Biomedical Analysis, Tsinghua University, Beijing 100084, China
Abstract
The frontal pole cortex (FPC) plays key roles in various higher-order functions and is highly developed in non-human primates. An essential missing piece of information is the detailed anatomical connections for finer parcellation of the macaque FPC than provided by the previous tracer results. This is important for understanding the functional architecture of the cerebral cortex. Here, combining cross-validation and principal component analysis, we formed a tractography-based parcellation scheme that applied a machine learning algorithm to divide the macaque FPC (2 males and 6 females) into eight subareas using high-resolution diffusion magnetic resonance imaging with the 9.4T Bruker system, and then revealed their subregional connections. Furthermore, we applied improved hierarchical clustering to the obtained parcels to probe the modular structure of the subregions, and found that the dorsolateral FPC, which contains an extension to the medial FPC, was mainly connected to regions of the default-mode network. The ventral FPC was mainly involved in the social-interaction network and the dorsal FPC in the metacognitive network. These results enhance our understanding of the anatomy and circuitry of the macaque brain, and contribute to FPC-related clinical research.
Keywords
Macaque； Frontal pole cortex； Anatomical connectivity profile； Parcellation； Neuroimaging； Principal component analysis
