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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

Inset shows fiber tracts of the fimbria-fornix (blue).Graphs show quantified results of FA (top) and MD (bottom) in left and right fimbria fornix.
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pone.0124885.g004: Inset shows fiber tracts of the fimbria-fornix (blue).Graphs show quantified results of FA (top) and MD (bottom) in left and right fimbria fornix.

Mentions: Repeated-measures ANOVAs for FA of each fiber track yielded group-by-session interactions in the genu (F(2,55) = 4.95, p = .010) but not the splenium (F(2,55) = .88, p = .42) (Fig 3). Interactions were also significant for both the left (F(2,55) = 7.91, p = .0009) and right (F(2,55) = 6.09, p = .004) fimbria-fornix tract (Fig 4). In all cases, paired t-tests indicated that the interaction was attributable to a significant drop in FA from the first to the second DTI session followed by a return in FA, observed in the alcohol but not the control group. For MD, the alcohol effect, identified as group-by-session interactions, was limited to the fimbria-fornix: left (F(2,55) = 8.71, p = .0005) and right (F(2,55) = 11.40, p = .00007). In complement to FA, the interaction indicated a rise in MD followed by a return to baseline in the alcohol-treated group only. One control animal had an exceptionally high MD at DTI 2, but the results were the same with or without its data in the analysis. ANOVAs based on data from animals that completed two or more DTI sessions yielded the same results as the ANOVAs based on rats with complete sessions.


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)

Inset shows fiber tracts of the fimbria-fornix (blue).Graphs show quantified results of FA (top) and MD (bottom) in left and right fimbria fornix.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0124885.g004: Inset shows fiber tracts of the fimbria-fornix (blue).Graphs show quantified results of FA (top) and MD (bottom) in left and right fimbria fornix.
Mentions: Repeated-measures ANOVAs for FA of each fiber track yielded group-by-session interactions in the genu (F(2,55) = 4.95, p = .010) but not the splenium (F(2,55) = .88, p = .42) (Fig 3). Interactions were also significant for both the left (F(2,55) = 7.91, p = .0009) and right (F(2,55) = 6.09, p = .004) fimbria-fornix tract (Fig 4). In all cases, paired t-tests indicated that the interaction was attributable to a significant drop in FA from the first to the second DTI session followed by a return in FA, observed in the alcohol but not the control group. For MD, the alcohol effect, identified as group-by-session interactions, was limited to the fimbria-fornix: left (F(2,55) = 8.71, p = .0005) and right (F(2,55) = 11.40, p = .00007). In complement to FA, the interaction indicated a rise in MD followed by a return to baseline in the alcohol-treated group only. One control animal had an exceptionally high MD at DTI 2, but the results were the same with or without its data in the analysis. ANOVAs based on data from animals that completed two or more DTI sessions yielded the same results as the ANOVAs based on rats with complete sessions.

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