Quantitative architectural analysis: a new approach to cortical mapping

Schleicher, Axel; Palomero‐Gallagher, Nicola; Morosan, Patricia; Eickhoff, Simon B.; Kowalski, T.; Vos, K. de; Amunts, Katrin; Zilles, Karl

doi:10.1007/s00429-005-0028-2

Cited by 149 publications

(137 citation statements)

References 36 publications

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“…Curvilinear traverses, running perpendicular to the cortical layers from the outer to the inner contour (Fig. 2D), were automatically calculated based on the Laplace equation (Annese et al, 2004;Jones et al, 2000;Schleicher et al, 2005;Schmitt and Bohme, 2002). Along these traverses, profiles describing the changes in the laminar cell density pattern (Schleicher et al, 2000(Schleicher et al, , 2005 were extracted from the GLI images.…”

Section: Cytoarchitectonic Mappingmentioning

confidence: 99%

“…Probabilistic cytoarchitectonic maps Eickhoff et al, 2005a;Zilles et al, 2002), on the other hand, provide a tool for more valid inferences about structure-function relationships in the human brain, since these maps are based on the observer-independent cytoarchitectonic analysis of 10 postmortem brains (Schleicher et al, 2005). They contain stereotaxic information about the location and variability of cortical areas in the Montreal Neurological Institute (MNI) reference space (Evans et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

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Ventral visual cortex in humans: Cytoarchitectonic mapping of two extrastriate areas

Rottschy

Eickhoff

Schleicher

et al. 2007

Human Brain Mapping

169

166

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The extrastriate visual cortex forms a complex system enabling the analysis of visually presented objects. To gain deeper insight into the anatomical basis of this system, we cytoarchitectonically mapped the ventral occipital cortex lateral to BA 18/V2 in 10 human postmortem brains. The anatomical characterization of this part of the ventral stream was performed by examination of cell-body-stained histological sections using quantitative cytoarchitectonic analysis. First, the gray level index (GLI) was measured in the ventral occipital lobe. Cytoarchitectonic borders, i.e., significant changes in the cortical lamination pattern, were then identified using an observer-independent algorithm based on multivariate analysis of GLI profiles. Two distinct cytoarchitectonic areas (hOC3v, hOC4v) were characterized in the ventral extrastriate cortex lateral to BA 18/V2. Area hOC3v was found in the collateral sulcus. hOC4v was located in this sulcus and also covered the fusiform gyrus in more occipital sections. Topographically, these areas thus seem to represent the anatomical substrates of functionally defined areas, VP/V3v and V4/V4v. Following histological analysis, the delineated cytoarchitectonic areas were transferred to 3D reconstructions of the respective postmortem brains, which in turn were spatially normalized to the Montreal Neurological Institute reference space. A probabilistic map was generated for each area which describes how many brains had a representation of this area in a particular voxel. These maps can now be used to identify the anatomical correlates of functional activations observed in neuroimaging experiments to enable a more informed investigation into the many open questions regarding the organization of the human visual cortex.

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Section: Cytoarchitectonic Mappingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ventral visual cortex in humans: Cytoarchitectonic mapping of two extrastriate areas

Rottschy

Eickhoff

Schleicher

et al. 2007

Human Brain Mapping

169

166

View full text Add to dashboard Cite

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“…Early systematic works by Bok (1929) established that folding of the cortex should preserve local volume of the layers, indicating that cortex maintains the local density of microstructure by modulating the relative thickness of layers with their curvature. This view was later discarded to favor an angle-preserving formulation, which guarantees that cortical profiles are strictly orthogonal to the lamination (Jones et al, 2000;Schleicher et al, 2005;Yezzi and Prince, 2003), with an elegant mathematical framework based on the Laplace equation.…”

Section: Defining the Laminar Depth Coordinate Systemmentioning

confidence: 99%

In-vivo magnetic resonance imaging (MRI) of laminae in the human cortex

et al. 2019

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The human neocortex is organized radially into six layers which differ in their myelination and the density and arrangement of neuronal cells. This cortical cyto-and myeloarchitecture plays a central role in the anatomical and functional neuroanatomy but is primarily accessible through invasive histology only. To overcome this limitation, several non-invasive MRI approaches have been, and are being, developed to resolve the anatomical cortical layers. As a result, recent studies on large populations and structure-function relationships at the laminar level became possible. Early proof-of-concept studies targeted conspicuous laminar structures such as the stria of Gennari in the primary visual cortex. Recent work characterized the laminar structure outside the visual cortex, investigated the relationship between laminar structure and function, and demonstrated layer-specific maturation effects. This paper reviews the methods and in-vivo MRI studies on the anatomical layers in the human cortex based on conventional and quantitative MRI (excluding diffusion imaging). A focus is on the related challenges, promises and potential future developments. The rapid development of MRI scanners, motion correction techniques, analysis methods and biophysical modeling promise to overcome the challenges of spatial resolution, precision and specificity of systematic imaging of cortical laminae. Need for non-invasive mapping of cortical laminationThe neocortex of the human brain consists of six layers which differ in their pattern of myelination (Nieuwenhuys, 2013;Vogt and Vogt, 1919) and the density and arrangement of neuronal cells (Brodmann, 1909;Zilles and Amunts, 2010). Those differences gave rise to the broad research field of myelo-and cyto-architecture, which is based on invasive histology. To facilitate studies of the human brain in large populations and longitudinally, non-invasive methods are much needed for visualizing intracortical anatomy in-vivo, since histological methods can only be applied ex-vivo. A promising approach is magnetic resonance imaging (MRI) as it is non-invasive and highly sensitive to the presence of myelin (and iron) in the cortex (Stüber et al., 2014). It is expected to reflect the myeloarchitecture rather than the cyto-architecture, although there is a strong correspondence between the two . Scope of the reviewThis paper reviews the recent in-vivo MRI studies on the anatomical layers in the human neocortex. An additional focus is on the related challenges, promises and potential future developments. Studies using diffusion weighted MRI are excluded from this review, since they are covered by Assaf et al. (2017) in the same special issue on "Prospects for cortical laminar MRI: functional and anatomical imaging of cerebral cortical layers". MRI studies of cortical layers Studies of the stria of GennariAs the cortex is only 2-4 mm thick and convoluted (Fischl and Dale, 2000), mapping cortical layers requires sub-millimeter isotropic resolution. Another challenge is that the differences in myelo-ar...

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“…Many other brain areas show characteristic myelination patterns (8,9), and systematic analyses of this type of structural information may provide important clues about the brain's functional organization. Whole-brain postmortem studies of cellular distributions and myelin content in human brain sections at high resolution have previously been described (8,10).…”

Section: Masakimentioning

confidence: 99%

Layer-specific variation of iron content in cerebral cortex as a source of MRI contrast

Fukunaga

Gelderen

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

393

409

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Recent advances in high-field MRI have dramatically improved the visualization of human brain anatomy in vivo. Most notably, in cortical gray matter, strong contrast variations have been observed that appear to reflect the local laminar architecture. This contrast has been attributed to subtle variations in the magnetic properties of brain tissue, possibly reflecting varying iron and myelin content. To establish the origin of this contrast, MRI data from postmortem brain samples were compared with electron microscopy and histological staining for iron and myelin. The results show that iron is distributed over laminae in a pattern that is suggestive of each region's myeloarchitecture and forms the dominant source of the observed MRI contrast. myelin | ferritin | laminar variation | brain structure | magnetic susceptibility M uch of the human cerebral cortex is organized in a network of functionally specialized regions. This understanding forms the basis of studies that attempt to expose the brain's inner workings using modern functional imaging techniques such as PET and MRI (1, 2). Some of this functional specialization is reflected in the local cortical architecture, and may be observed in postmortem brain samples from the laminar and columnar variation in a number of tissue properties including cell shape (3), myelin content (4), metabolic state (5), neurochemical profile (6), and receptor density (7).One of the most striking examples of this structure-function relationship is in the primary visual cortex (V1, or Brodmann area 17), which is involved in the early stages of visual information processing. Visual area V1 can be readily identified with postmortem tissue analysis based on the prominence of myelinated fibers in layer IVb, known as the line of Gennari. Many other brain areas show characteristic myelination patterns (8, 9), and systematic analyses of this type of structural information may provide important clues about the brain's functional organization. Whole-brain postmortem studies of cellular distributions and myelin content in human brain sections at high resolution have previously been described (8, 10).A number of attempts have been made to reveal laminar cortical structure in vivo with structural MRI, by exploiting contrast based on the altered density and NMR relaxation times of water protons in myelin-rich environments (11)(12)(13)(14)(15). Although these studies have had some success, their impact has not been widespread as a result of the rather limited contrast and resolution available with conventional MRI. Nevertheless, much progress has been made over the last few years. Recent developments in high-field MRI (≥7 T) have increased spatial resolution to less than 300 μm (16-18), and improved the ability to detect subtle variations in the magnetic susceptibility of tissue. These variations are reflected in a number of intrinsic MRI parameters, including the longitudinal relaxation rate R 1 , the transverse relaxation rates R 2 and R 2 *, and the NMR resonance frequency. R 2 * indicates th...

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Quantitative architectural analysis: a new approach to cortical mapping

Cited by 149 publications

References 36 publications

Ventral visual cortex in humans: Cytoarchitectonic mapping of two extrastriate areas

Ventral visual cortex in humans: Cytoarchitectonic mapping of two extrastriate areas

In-vivo magnetic resonance imaging (MRI) of laminae in the human cortex

Layer-specific variation of iron content in cerebral cortex as a source of MRI contrast

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