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Cortical thickness gradients in structural hierarchies.

Wagstyl K, Ronan L, Goodyer IM, Fletcher PC - Neuroimage (2015)

Bottom Line: Our results suggest that an easily measurable macroscopic brain parameter, namely, cortical thickness, is systematically related to cytoarchitecture and to the structural hierarchical organisation of the cortex.We argue that the measurement of cortical thickness gradients may become an important way to develop our understanding of brain structure-function relationships.The identification of alterations in such gradients may complement the observation of regionally localised cortical thickness changes in our understanding of normal development and neuropsychiatric illnesses.

View Article: PubMed Central - PubMed

Affiliation: Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Cambridge, CB2 3EB, UK. Electronic address: kw350@cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Distance measures. Geodesic distance measures the shortest path between two points across the white matter (or pial) surface of the cortex. Euclidean distance is the shortest distance through 3-dimensional space. White matter tract distance approximates the length of an axon connecting two regions.
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f0010: Distance measures. Geodesic distance measures the shortest path between two points across the white matter (or pial) surface of the cortex. Euclidean distance is the shortest distance through 3-dimensional space. White matter tract distance approximates the length of an axon connecting two regions.

Mentions: In summary, this study began by evaluating whether cortical thickness is a surrogate marker of laminar differentiation. Subsequently, we investigated whether connectivity and functional hierarchies are organised in accordance with structural gradients. We used structural MR images from macaque and human subjects. For each subject, thickness gradients were quantified for three separate hierarchies in each species, namely, visual, somatosensory and auditory. Hierarchical level was identified in the macaque using standardised parcellation maps and tracer-derived hierarchies (Felleman and Van Essen, 1991; Barbas, 1986). With respect to the human data set, given a lack of precise knowledge about the layout of structural hierarchies, we used geodesic distance from the primary sensory region as a proxy measure of hierarchical position, having validated this approach against macaque hierarchies (Fig. 1). Geodesic distance also offers a means of analysis which obviates differences between the various hierarchical models that exist. Finally, we compared thickness against a functionally derived visual hierarchy. Importantly, all measures of cortical thickness were adjusted to account for the local effects of folding.


Cortical thickness gradients in structural hierarchies.

Wagstyl K, Ronan L, Goodyer IM, Fletcher PC - Neuroimage (2015)

Distance measures. Geodesic distance measures the shortest path between two points across the white matter (or pial) surface of the cortex. Euclidean distance is the shortest distance through 3-dimensional space. White matter tract distance approximates the length of an axon connecting two regions.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401442&req=5

f0010: Distance measures. Geodesic distance measures the shortest path between two points across the white matter (or pial) surface of the cortex. Euclidean distance is the shortest distance through 3-dimensional space. White matter tract distance approximates the length of an axon connecting two regions.
Mentions: In summary, this study began by evaluating whether cortical thickness is a surrogate marker of laminar differentiation. Subsequently, we investigated whether connectivity and functional hierarchies are organised in accordance with structural gradients. We used structural MR images from macaque and human subjects. For each subject, thickness gradients were quantified for three separate hierarchies in each species, namely, visual, somatosensory and auditory. Hierarchical level was identified in the macaque using standardised parcellation maps and tracer-derived hierarchies (Felleman and Van Essen, 1991; Barbas, 1986). With respect to the human data set, given a lack of precise knowledge about the layout of structural hierarchies, we used geodesic distance from the primary sensory region as a proxy measure of hierarchical position, having validated this approach against macaque hierarchies (Fig. 1). Geodesic distance also offers a means of analysis which obviates differences between the various hierarchical models that exist. Finally, we compared thickness against a functionally derived visual hierarchy. Importantly, all measures of cortical thickness were adjusted to account for the local effects of folding.

Bottom Line: Our results suggest that an easily measurable macroscopic brain parameter, namely, cortical thickness, is systematically related to cytoarchitecture and to the structural hierarchical organisation of the cortex.We argue that the measurement of cortical thickness gradients may become an important way to develop our understanding of brain structure-function relationships.The identification of alterations in such gradients may complement the observation of regionally localised cortical thickness changes in our understanding of normal development and neuropsychiatric illnesses.

View Article: PubMed Central - PubMed

Affiliation: Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Cambridge, CB2 3EB, UK. Electronic address: kw350@cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus