Diffusion-weighted imaging tractography-based parcellation of the human lateral premotor cortex identifies dorsal and ventral subregions with anatomical and functional specializations.
Lateral premotor cortex (PM) in the macaque monkey can be segregated into structurally and functionally distinct subregions, including a major division between dorsal (PMd) and ventral (PMv) parts, which have distinct cytoarchitecture, function, and patterns of connectivity with both frontal and parietal cortical areas. The borders of their subregions are less well defined in the human brain. Here we use diffusion tractography to identify a reproducible border between dorsal and ventral subregions of human precentral gyrus. We derive connectivity fingerprints for the two subregions and demonstrate that each has a distinctive pattern of connectivity with frontal cortex and lateral parietal cortex, suggesting that these areas correspond to human PMd and PMv. Although putative human PMd has a high probability of connection with the superior parietal lobule, dorsal prefrontal cortex, and cingulate cortex, human PMv has a higher probability of connection with the anterior inferior parietal lobule and ventral prefrontal cortex. Finally, we assess the correspondence between our PMd/PMv border and local sulcal and functional anatomy. The location of the border falls at the level of the gyral branch that divides the inferior precentral sulcus from the superior precentral sulcus and corresponded closely to the location of a functional border defined using previous functional magnetic resonance imaging studies.
Tomassini
Valentina
V
Centre for Functional MRI of the Brain, University of Oxford, Oxford OX3 9DU, United Kingdom.
Jbabdi
Saad
S
Klein
Johannes C
JC
Behrens
Timothy E J
TE
Pozzilli
Carlo
C
Matthews
Paul M
PM
Rushworth
Matthew F S
MF
Johansen-Berg
Heidi
H
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology