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Dynamic responses of selective brain white matter fiber tracts to binge alcohol and recovery in the rat.

Pfefferbaum A, Zahr NM, Mayer D, Rohlfing T, Sullivan EV - PLoS ONE (2015)

Bottom Line: Binge alcohol followed by a week of sobriety resulted in rapidly reversible decreases in fractional anisotropy (FA), a measure of the coherence of fiber tracts, in callosal genu and fimbria-fornix but not splenium; and increases in mean diffusivity (MD), an index of freely diffusing water in tissue, selective to the fimbria-fornix.These effects were confirmed with tract-based spatial statistics (TBSS).The directionality of changes in DTI metrics reproduce those observed in human alcoholism.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Program, SRI International, Menlo Park, CA, United States of America; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States of America.

ABSTRACT
To determine the dynamics of white matter vulnerability to excessive alcohol consumption, diffusion tensor imaging (DTI) was used in an animal model of alcohol exposure. Quantitative, in vivo fiber tracking results are presented from rats with DTI conducted at 3 time points: baseline; after 4 days of intragastric alcohol to blood alcohol levels of ~250 mg/dL; and after one week of recovery. Binge alcohol followed by a week of sobriety resulted in rapidly reversible decreases in fractional anisotropy (FA), a measure of the coherence of fiber tracts, in callosal genu and fimbria-fornix but not splenium; and increases in mean diffusivity (MD), an index of freely diffusing water in tissue, selective to the fimbria-fornix. These effects were confirmed with tract-based spatial statistics (TBSS). The directionality of changes in DTI metrics reproduce those observed in human alcoholism. That a single exposure to binge alcohol can cause substantial transient changes detectable in DTI metrics demonstrates the potential for rapid neuroplasticity.

No MeSH data available.


Related in: MedlinePlus

FA maps with circles indicating regions of the genu (right) and splenium (middle) of the corpus callosum and fimbria-fornix (left) used for fiber tract quantification of FA and MD.
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pone.0124885.g002: FA maps with circles indicating regions of the genu (right) and splenium (middle) of the corpus callosum and fimbria-fornix (left) used for fiber tract quantification of FA and MD.

Mentions: To improve the precision of target locations, an automated 5-point, 3-dimensional local maximum search within the FA image ensured location of the target within the center of the given fiber track. The identified point was then expanded to a target, which was a 7 x 7 plane, 3-voxels thick, perpendicular to fiber orientation. Thresholds used included an FA value limit of .17 and an angle maximum of 37°. Tracking sources were automatically defined as planes parallel to the genu and splenium targets and anterior/posterior to the fimbria-fornix. Quantitative fiber tracking routines and parameters, developed by Mori and Xu [51,52] and distributed by G. Gerig [53] (www.ia.unc.edu/dev/download/fibertracking), were used and produced pictorial fiber bundle representations. Quantification of the mean FA and MD of the fibers were similar to those we have previously used in vivo in the human brain [7,54] and rat brain [44]. Mean FA and MD were calculated for fibers of the genu and splenium of the corpus callosum, and left and right fimbria-fornix tracts (Fig 2).


Dynamic responses of selective brain white matter fiber tracts to binge alcohol and recovery in the rat.

Pfefferbaum A, Zahr NM, Mayer D, Rohlfing T, Sullivan EV - PLoS ONE (2015)

FA maps with circles indicating regions of the genu (right) and splenium (middle) of the corpus callosum and fimbria-fornix (left) used for fiber tract quantification of FA and MD.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403879&req=5

pone.0124885.g002: FA maps with circles indicating regions of the genu (right) and splenium (middle) of the corpus callosum and fimbria-fornix (left) used for fiber tract quantification of FA and MD.
Mentions: To improve the precision of target locations, an automated 5-point, 3-dimensional local maximum search within the FA image ensured location of the target within the center of the given fiber track. The identified point was then expanded to a target, which was a 7 x 7 plane, 3-voxels thick, perpendicular to fiber orientation. Thresholds used included an FA value limit of .17 and an angle maximum of 37°. Tracking sources were automatically defined as planes parallel to the genu and splenium targets and anterior/posterior to the fimbria-fornix. Quantitative fiber tracking routines and parameters, developed by Mori and Xu [51,52] and distributed by G. Gerig [53] (www.ia.unc.edu/dev/download/fibertracking), were used and produced pictorial fiber bundle representations. Quantification of the mean FA and MD of the fibers were similar to those we have previously used in vivo in the human brain [7,54] and rat brain [44]. Mean FA and MD were calculated for fibers of the genu and splenium of the corpus callosum, and left and right fimbria-fornix tracts (Fig 2).

Bottom Line: Binge alcohol followed by a week of sobriety resulted in rapidly reversible decreases in fractional anisotropy (FA), a measure of the coherence of fiber tracts, in callosal genu and fimbria-fornix but not splenium; and increases in mean diffusivity (MD), an index of freely diffusing water in tissue, selective to the fimbria-fornix.These effects were confirmed with tract-based spatial statistics (TBSS).The directionality of changes in DTI metrics reproduce those observed in human alcoholism.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience Program, SRI International, Menlo Park, CA, United States of America; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States of America.

ABSTRACT
To determine the dynamics of white matter vulnerability to excessive alcohol consumption, diffusion tensor imaging (DTI) was used in an animal model of alcohol exposure. Quantitative, in vivo fiber tracking results are presented from rats with DTI conducted at 3 time points: baseline; after 4 days of intragastric alcohol to blood alcohol levels of ~250 mg/dL; and after one week of recovery. Binge alcohol followed by a week of sobriety resulted in rapidly reversible decreases in fractional anisotropy (FA), a measure of the coherence of fiber tracts, in callosal genu and fimbria-fornix but not splenium; and increases in mean diffusivity (MD), an index of freely diffusing water in tissue, selective to the fimbria-fornix. These effects were confirmed with tract-based spatial statistics (TBSS). The directionality of changes in DTI metrics reproduce those observed in human alcoholism. That a single exposure to binge alcohol can cause substantial transient changes detectable in DTI metrics demonstrates the potential for rapid neuroplasticity.

No MeSH data available.


Related in: MedlinePlus