Article

Behrens, T. E. et al. Non-invasive mapping of connections between human thalamus and cortex using diffusion imaging. Nature Neurosci. 6, 750-757

Department of Engineering Science, University of Oxford, Oxford, England, United Kingdom
Nature Neuroscience (Impact Factor: 16.1). 08/2003; 6(7):750-7. DOI: 10.1038/nn1075
Source: PubMed

ABSTRACT

Evidence concerning anatomical connectivities in the human brain is sparse and based largely on limited post-mortem observations. Diffusion tensor imaging has previously been used to define large white-matter tracts in the living human brain, but this technique has had limited success in tracing pathways into gray matter. Here we identified specific connections between human thalamus and cortex using a novel probabilistic tractography algorithm with diffusion imaging data. Classification of thalamic gray matter based on cortical connectivity patterns revealed distinct subregions whose locations correspond to nuclei described previously in histological studies. The connections that we found between thalamus and cortex were similar to those reported for non-human primates and were reproducible between individuals. Our results provide the first quantitative demonstration of reliable inference of anatomical connectivity between human gray matter structures using diffusion data and the first connectivity-based segmentation of gray matter.

Download full-text

Full-text

Available from: Paul M Matthews, Jan 11, 2015
  • Source
    • "The detailed description of WM modifications was made possible using the development of Diffusion Tensor Imaging (DTI). DTI is an established method for studying in vivo the WM pathways and has the ability to reveal structural properties of the WM (Basser et al., 2000; Le Bihan et al., 2001; Behrens et al., 2003) by measuring water diffusion at mesoscopic resolution in brain tissue. It has been shown that axonal structure, cell membrane, and myelin sheath strongly influence water diffusion. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Microstructural changes of White Matter (WM) associated with aging have been widely described through Diffusion Tensor Imaging (DTI) parameters. In parallel, White Matter Hyperintensities (WMH) as observed on a T2-MRI are extremely common in older individuals. However, few studies have investigated both phenomena conjointly. The present study investigates aging effects on DTI parameters in absence and in presence of WMH. Diffusion maps were constructed based on 21 directions DTI scans of young adults (n=19, mean age=33 SD=7.4) and two age-matched groups of older adults, one presenting low-level-WMH (n=20, mean age=78, SD= 3.2) and one presenting high-level-WMH (n=20, mean age=79, SD= 5.4). Older subjects with low-level-WMH presented modifications of DTI parameters in comparison to younger subjects, fitting with the DTI pattern classically described in aging, i.e. Fractional Anisotropy (FA) decrease/Radial Diffusivity (RD) increase. Furthermore, older subjects with high-level-WMH showed higher DTI modifications in Normal Appearing White Matter (NAWM) in comparison to those with low-level-WMH. Finally, in older subjects with high-level-WMH, FA or RD values of NAWM were associated with to WMH burden. Therefore, our findings suggest that DTI modifications and the presence of WMH would be two inter-dependent processes but occurring within different temporal windows. DTI changes would reflect the early phase of white matter changes and WMH would appear as a consequence of those changes.
    Full-text · Article · Feb 2016 · Frontiers in Aging Neuroscience
  • Source
    • "The thalamic nuclei are connected with the cerebral cortex via reciprocal connections in a topographically organized fashion. This has been portrayed in the classical anatomical literature (e.g.,Parent, 1996) and recently with the advent of diffusion imaging (Behrens et al., 2003;Johansen Berg et al., 2005;Makris et al., 1999). Cortico-striatal Tracts. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We have developed a novel method to describe human white matter anatomy using an approach that is both intuitive and simple to use, and which automatically extracts white matter tracts from diffusion MRI volumes. Further, our method simplifies the quantification and statistical analysis of white matter tracts on large diffusion MRI databases. This work reflects the careful syntactical definition of major white matter fiber tracts in the human brain based on a neuroanatomist's expert knowledge. The framework is based on a novel query language with a near-to-English textual syntax. This query language makes it possible to construct a dictionary of anatomical definitions that describe white matter tracts. The definitions include adjacent gray and white matter regions, and rules for spatial relations. This novel method makes it possible to automatically label white matter anatomy across subjects. After describing this method, we provide an example of its implementation where we encode anatomical knowledge in human white matter for 10 association and 15 projection tracts per hemisphere, along with 7 commissural tracts. Importantly, this novel method is comparable in accuracy to manual labeling. Finally, we present results applying this method to create a white matter atlas from 77 healthy subjects, and we use this atlas in a small proof-of-concept study to detect changes in association tracts that characterize schizophrenia.
    Full-text · Article · Dec 2015 · Brain Structure and Function
  • Source
    • "Although the VIM-related FC networks identified in the ET patients and the HCs are highly consistent with the individual anatomical connectivity networks revealed by invasive tract-tracing and noninvasive DTI studies of normal non-human primates [Asanuma et al., 1983a; Yamamoto et al., 1983] and healthy humans [Behrens et al., 2003; Johansen-Berg et al., 2005; Kincses et al., 2012], we must use caution when interpreting these findings, especially when applying them at an individual level. Additionally , to reveal the characteristic profiles of ET, a homogenous entity is necessary because growing evidence has suggested that ET is not a single disease but rather is a family of diseases or a syndrome [Louis et al., 2014]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The clinical benefits of targeting the ventral intermediate nucleus (VIM) for the treatment of tremors in essential tremor (ET) patients suggest that the VIM is a key hub in the network of tremor generation and propagation and that the VIM can be considered as a seed region to study the tremor network. However, little is known about the central tremor network in ET patients. Twenty-six ET patients and 26 matched healthy controls (HCs) were included in this study. After considering structural and head-motion factors and establishing the accuracy of our seed region, a VIM seed-based functional connectivity (FC) analysis of resting-state functional magnetic resonance imaging (RS-fMRI) data was performed to characterize the VIM FC network in ET patients. We found that ET patients and HCs shared a similar VIM FC network that was generally consistent with the VIM anatomical connectivity network inferred from normal nonhuman primates and healthy humans. Compared with HCs, ET patients displayed VIM-related FC changes, primarily within the VIM-motor cortex (MC)-cerebellum (CBLM) circuit, which included decreased FC in the CBLM and increased FC in the MC. Importantly, tremor severity correlated with these FC changes. These findings provide the first evidence that the pathological tremors observed in ET patients might be based on a physiologically pre-existing VIM - MC - CBLM network and that disruption of FC in this physiological network is associated with ET. Further, these findings demonstrate a potential approach for elucidating the neural network mechanisms underlying this disease. Hum Brain Mapp, 2015. © 2015 Wiley Periodicals, Inc.
    Full-text · Article · Oct 2015 · Human Brain Mapping
Show more