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Altered anatomical network in early blindness revealed by diffusion tensor tractography.

Shu N, Liu Y, Li J, Li Y, Yu C, Jiang T - PLoS ONE (2009)

Bottom Line: Compared with controls, early blind subjects showed a decreased degree of connectivity, a reduced global efficiency, and an increased characteristic path length in their brain anatomical network, especially in the visual cortex.Moreover, we revealed some regions with motor or somatosensory function have increased connections with other brain regions in the early blind, which suggested experience-dependent compensatory plasticity.From the results, we suggest that analyzing the brain's anatomical network obtained using diffusion MRI data provides new insights into the understanding of the brain's re-organization in the specific population with early visual deprivation.

View Article: PubMed Central - PubMed

Affiliation: LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. Diffusion MRI studies have revealed the efficient small-world properties and modular structure of the anatomical network in normal subjects. However, no previous study has used diffusion MRI to reveal changes in the brain anatomical network in early blindness. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 17 early blind subjects and 17 age- and gender-matched sighted controls. We established the existence of structural connections between any pair of the 90 cortical and sub-cortical regions using deterministic tractography. Compared with controls, early blind subjects showed a decreased degree of connectivity, a reduced global efficiency, and an increased characteristic path length in their brain anatomical network, especially in the visual cortex. Moreover, we revealed some regions with motor or somatosensory function have increased connections with other brain regions in the early blind, which suggested experience-dependent compensatory plasticity. This study is the first to show alterations in the topological properties of the anatomical network in early blindness. From the results, we suggest that analyzing the brain's anatomical network obtained using diffusion MRI data provides new insights into the understanding of the brain's re-organization in the specific population with early visual deprivation.

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Related in: MedlinePlus

Representation of the reconstructed IFO fasciculi for a normal and blind subject.The tracked fibers are overlaied on the individual's anatomical image (T1-weighted). Left: normal subject NC07; right: blind subject EB09.
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pone-0007228-g005: Representation of the reconstructed IFO fasciculi for a normal and blind subject.The tracked fibers are overlaied on the individual's anatomical image (T1-weighted). Left: normal subject NC07; right: blind subject EB09.

Mentions: Through statistical comparison of nodal properties, we revealed most of altered brain regions were located in the inferior frontal and occipital lobe in the anatomical network, to further investigate whether these changes were related to the alterations of the integrity of the white matter tracts connecting these two regions, we reconstructed the long-distance anatomical connections between the inferior frontal lobe and the occipital lobe: the inferior fronto-occipital (IFO) fasciculus. For each subject, the bilateral IFO fasciculi can be well reconstructed (Figure 5). Through the statistical analysis of the mean fractional anisotropy (FA) in IFO fasciculi between groups, we found that the early blind subjects have significantly lower FA values than the sighted subjects (p = 0.002) (Figure 6). The analysis results also revealed there was a significant main effect of hemisphere (p = 0.005) and no significant group-by-hemisphere interaction (p>0.1).


Altered anatomical network in early blindness revealed by diffusion tensor tractography.

Shu N, Liu Y, Li J, Li Y, Yu C, Jiang T - PLoS ONE (2009)

Representation of the reconstructed IFO fasciculi for a normal and blind subject.The tracked fibers are overlaied on the individual's anatomical image (T1-weighted). Left: normal subject NC07; right: blind subject EB09.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2747271&req=5

pone-0007228-g005: Representation of the reconstructed IFO fasciculi for a normal and blind subject.The tracked fibers are overlaied on the individual's anatomical image (T1-weighted). Left: normal subject NC07; right: blind subject EB09.
Mentions: Through statistical comparison of nodal properties, we revealed most of altered brain regions were located in the inferior frontal and occipital lobe in the anatomical network, to further investigate whether these changes were related to the alterations of the integrity of the white matter tracts connecting these two regions, we reconstructed the long-distance anatomical connections between the inferior frontal lobe and the occipital lobe: the inferior fronto-occipital (IFO) fasciculus. For each subject, the bilateral IFO fasciculi can be well reconstructed (Figure 5). Through the statistical analysis of the mean fractional anisotropy (FA) in IFO fasciculi between groups, we found that the early blind subjects have significantly lower FA values than the sighted subjects (p = 0.002) (Figure 6). The analysis results also revealed there was a significant main effect of hemisphere (p = 0.005) and no significant group-by-hemisphere interaction (p>0.1).

Bottom Line: Compared with controls, early blind subjects showed a decreased degree of connectivity, a reduced global efficiency, and an increased characteristic path length in their brain anatomical network, especially in the visual cortex.Moreover, we revealed some regions with motor or somatosensory function have increased connections with other brain regions in the early blind, which suggested experience-dependent compensatory plasticity.From the results, we suggest that analyzing the brain's anatomical network obtained using diffusion MRI data provides new insights into the understanding of the brain's re-organization in the specific population with early visual deprivation.

View Article: PubMed Central - PubMed

Affiliation: LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. Diffusion MRI studies have revealed the efficient small-world properties and modular structure of the anatomical network in normal subjects. However, no previous study has used diffusion MRI to reveal changes in the brain anatomical network in early blindness. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 17 early blind subjects and 17 age- and gender-matched sighted controls. We established the existence of structural connections between any pair of the 90 cortical and sub-cortical regions using deterministic tractography. Compared with controls, early blind subjects showed a decreased degree of connectivity, a reduced global efficiency, and an increased characteristic path length in their brain anatomical network, especially in the visual cortex. Moreover, we revealed some regions with motor or somatosensory function have increased connections with other brain regions in the early blind, which suggested experience-dependent compensatory plasticity. This study is the first to show alterations in the topological properties of the anatomical network in early blindness. From the results, we suggest that analyzing the brain's anatomical network obtained using diffusion MRI data provides new insights into the understanding of the brain's re-organization in the specific population with early visual deprivation.

Show MeSH
Related in: MedlinePlus