Connectivity-based parcellation of the macaque frontal cortex, and its relation with the cytoarchitectonic distribution described in current atlases
Brain Struct Funct. 2016-07-28; 222(3): 1331-1349
DOI: 10.1007/s00429-016-1280-3
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1. Brain Struct Funct. 2017 Apr;222(3):1331-1349. doi: 10.1007/s00429-016-1280-3.
Epub 2016 Jul 28.
Connectivity-based parcellation of the macaque frontal cortex, and its relation
with the cytoarchitectonic distribution described in current atlases.
Cerliani L(1)(2), D’Arceuil H(3), Thiebaut de Schotten M(4)(5).
Author information:
(1)Brain Connectivity and Behaviour, Frontlab, Institut du Cerveau et de la
Moelle épinière (ICM), 47 Boulevard de l’Hôpital, Paris, France.
.
(2)CNRS U7225, Inserm U1127, GH Pitié-Salpêtrière, 75013, Paris, France.
.
(3)Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA,
USA.
(4)Brain Connectivity and Behaviour, Frontlab, Institut du Cerveau et de la
Moelle épinière (ICM), 47 Boulevard de l’Hôpital, Paris, France.
(5)CNRS U7225, Inserm U1127, GH Pitié-Salpêtrière, 75013, Paris, France.
Through its connectivity with the rest of the brain, a cortical region constrains
its function. The advent of MRI methods such as diffusion-weighted imaging
tractography allows us to estimate whole-brain anatomical connectivity at
multiple seed regions in the same subject. This makes it possible to use
data-driven techniques to define the spatial boundaries between adjacent brain
regions characterized by sharply different connectivity. This approach has
recently been employed to identify connectivity-based subdivisions of the human
frontal lobe bearing an apparent similarity with cytoarchitectural subdivisions.
However, the spatial relationships between the boundaries of cytoarchitectonic
areas and tractography-based subdivisions remain largely hypothetical. In this
work we present the first tractography-based parcellation of the frontal lobes in
macaques. Diffusion-weighted data for tractography were acquired on ex vivo
macaque brain specimens, ruling out the presence of various sources of noise
present in acquisitions on living subjects. An unsupervised multivariate
technique consistently showed the presence of 11 tractography-driven subdivisions
in the frontal lobe across specimens. Comparison with several microstructural
atlases suggested a heterogeneous relationship of these subdivisions with
cytoarchitectonic areas: caudal frontal, medial and orbitofronal subdivisions
featured the most consistent relationship between modalities, while lateral
prefrontal subdivisions mostly differed from atlas-based cytoarchitectonic
subdivisions. Other subdivisions were reminiscent of the organization of
anatomical projections of the caudal motor cortex, as well as of the intrinsic
orbitofrontal networks. Hence, although some cytoarchitectural and
connectivity-based subdivisions share a similar spatial distribution, they should
not necessarily be considered as equivalent. Instead, connectivity-based
subdivisions appear to provide complementary information on the spatial
organization of anatomical connectivity.
DOI: 10.1007/s00429-016-1280-3
PMID: 27469273 [Indexed for MEDLINE]