Large-scale brain networks of the human left temporal pole: a functional connectivity MRI study.
The most rostral portion of the human temporal cortex, the temporal pole (TP), has been described as "enigmatic" because its functional neuroanatomy remains unclear. Comparative anatomy studies are only partially helpful, because the human TP is larger and cytoarchitectonically more complex than in nonhuman primates. Considered by Brodmann as a single area (BA 38), the human TP has been recently parceled into an array of cytoarchitectonic subfields. In order to clarify the functional connectivity of subregions of the TP, we undertook a study of 172 healthy adults using resting-state functional connectivity MRI. Remarkably, a hierarchical cluster analysis performed to group the seeds into distinct subsystems according to their large-scale functional connectivity grouped 87.5% of the seeds according to the recently described cytoarchitectonic subregions of the TP. Based on large-scale functional connectivity, there appear to be 4 major subregions of the TP: (1) dorsal, with predominant connectivity to auditory/somatosensory and language networks; (2) ventromedial, predominantly connected to visual networks; (3) medial, connected to paralimbic structures; and (4) anterolateral, connected to the default-semantic network. The functional connectivity of the human TP, far more complex than its known anatomic connectivity in monkey, is concordant with its hypothesized role as a cortical convergence zone.
MGH Frontotemporal Dementia Unit, Alzheimer's Disease Research Center, Department of Neurology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Belen
B
Pascual
Section on Integrative Neuroimaging, National Institutes of Health, Bethesda, MD 20892, USA.
Joseph C
JC
Masdeu
MGH Frontotemporal Dementia Unit, Alzheimer's Disease Research Center, Department of Neurology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Mark
M
Hollenbeck
Center for Morphometric Analysis, Departments of Psychiatry, Neurology, and Radiology Services Center for Neural Systems Investigation, Departments of Neurology and Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Nikos
N
Makris
Center for Human Neuroanatomy Laboratory, Department of Health Sciences, School of Medicine, University of Castilla-La Mancha, Albacete 02071, Spain.
Ricardo
R
Insausti
Allen Institute for Brain Science, Seattle, WA 98103, USA.
Song-Lin
SL
Ding
MGH Frontotemporal Dementia Unit, Alzheimer's Disease Research Center, Department of Neurology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA Center for Neural Systems Investigation, Departments of Neurology and Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Bradford C
BC
Dickerson
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
anterior temporal lobe; brain anatomy; cytoarchitecture; language; resting-state fMRI