Connectional differences between humans and macaques in the MT+ complex

Jianxiong Ruan; Ye Yuan; Yicheng Qiao; Minghao Qiu; Xueda Dong; Yue Cui; Jianhong Wang; Ning Liu

doi:10.1016/j.isci.2024.111617

Connectional differences between humans and macaques in the MT+ complex

iScience. 2024 Dec 17;28(1):111617. doi: 10.1016/j.isci.2024.111617. eCollection 2025 Jan 17.

Authors

Jianxiong Ruan^{1

2}, Ye Yuan^{2

3}, Yicheng Qiao^{2

4}, Minghao Qiu⁵, Xueda Dong^{2

6

7}, Yue Cui^{8

9}, Jianhong Wang⁵, Ning Liu^{2

4}

Affiliations

¹ School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China.
² State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
³ Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK.
⁴ College of Life Sciences, University of Chinese Academy of Sciences, Beijing 101408, China.
⁵ National Resource Center for Non-Human Primates and National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
⁶ Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China.
⁷ Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing 101408, China.
⁸ Laboratory of Brain Atlas and Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.
⁹ School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 101408, China.

Abstract

MT+ is pivotal in the dorsal visual stream, encoding tool-use characteristics such as motion speed and direction. Despite its conservation between humans and monkeys, differences in MT+ spatial location and organization may lead to divergent, yet unexplored, connectivity patterns and functional characteristics. Using diffusion tensor imaging, we examined the structural connectivity of MT+ subregions in macaques and humans. We also employed graph-theoretical analyses on the constructed homologous tool-use network to assess their functional roles. Our results revealed location-dependent connectivity in macaques, with MST, MT, and FST predominantly connected to dorsal, middle, and ventral surfaces, respectively. Humans showed similar connectivity across all subregions. Differences in connectivity between MST and FST are more pronounced in macaques. In humans, the entire MT+ region, especially MST, exhibited stronger information transmission capabilities. Our findings suggest that the differences in tool use between humans and macaques may originate earlier than previously thought, particularly within the MT+ region.

Keywords: Biological sciences; Computer science; Physics.