TY - JOUR
T1 - MRI signature in a novel mouse model of genetically induced adult oligodendrocyte cell death
AU - Mueggler, Thomas
AU - Pohl, Hartmut
AU - Baltes, Christof
AU - Riethmacher, Dieter
AU - Suter, Ueli
AU - Rudin, Markus
N1 - Funding Information:
This work was supported by the Swiss National Science Foundation and the National Center for Competence in Research (NCCR) Neural Plasticity and Repair . We thank the Light Microscopy Center of the ETH Zurich, Switzerland , for excellent support.
PY - 2012/1/16
Y1 - 2012/1/16
N2 - Two general pathological processes contribute to multiple sclerosis (MS): acute inflammation and degeneration. While magnetic resonance imaging (MRI) is highly sensitive in detecting abnormalities related to acute inflammation both clinically and in animal models of experimental autoimmune encephalomyelitis (EAE), the correlation of these readouts with acute and future disabilities has been found rather weak. This illustrates the need for imaging techniques addressing neurodegenerative processes associated with MS. In the present work we evaluated the sensitivity of different MRI techniques (T 2 mapping, macrophage tracking based on labeling cells in vivo by ultrasmall particles of iron oxide (USPIO), diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI)) to detect histopathological changes in a novel animal model making use of intrinsic, temporally and spatially controlled triggering of oligodendrocyte cell death. This mouse model allows studying the MRI signature associated to neurodegenerative processes of MS in the absence of adaptive inflammatory components that appear to be foremost in the EAE models. Our results revealed pronounced T 2 hyperintensities in brain stem and cerebellar structures, which we attribute to structural alteration of white matter by pronounced vacuolation. Brain areas were found devoid of significant macrophage infiltration in line with the absence of a peripheral inflammatory response. The significant decrease in diffusion anisotropy derived from DTI measures in these structures is mainly caused by a pronounced decrease in diffusivity parallel to the fiber indicative of axonal damage. Triggering of oligodendrocyte ablation did not translate into a significant increase in radial diffusivity. Only minor decreases in MT ratio have been observed, which is attributed to inefficient removal of myelin debris.
AB - Two general pathological processes contribute to multiple sclerosis (MS): acute inflammation and degeneration. While magnetic resonance imaging (MRI) is highly sensitive in detecting abnormalities related to acute inflammation both clinically and in animal models of experimental autoimmune encephalomyelitis (EAE), the correlation of these readouts with acute and future disabilities has been found rather weak. This illustrates the need for imaging techniques addressing neurodegenerative processes associated with MS. In the present work we evaluated the sensitivity of different MRI techniques (T 2 mapping, macrophage tracking based on labeling cells in vivo by ultrasmall particles of iron oxide (USPIO), diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI)) to detect histopathological changes in a novel animal model making use of intrinsic, temporally and spatially controlled triggering of oligodendrocyte cell death. This mouse model allows studying the MRI signature associated to neurodegenerative processes of MS in the absence of adaptive inflammatory components that appear to be foremost in the EAE models. Our results revealed pronounced T 2 hyperintensities in brain stem and cerebellar structures, which we attribute to structural alteration of white matter by pronounced vacuolation. Brain areas were found devoid of significant macrophage infiltration in line with the absence of a peripheral inflammatory response. The significant decrease in diffusion anisotropy derived from DTI measures in these structures is mainly caused by a pronounced decrease in diffusivity parallel to the fiber indicative of axonal damage. Triggering of oligodendrocyte ablation did not translate into a significant increase in radial diffusivity. Only minor decreases in MT ratio have been observed, which is attributed to inefficient removal of myelin debris.
KW - Axonal injury
KW - Demyelination
KW - Diffusion tensor imaging
KW - Magnetic resonance imaging
KW - Mouse brain
KW - Oligodendrocyte cell death
KW - T hyperintensities
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U2 - 10.1016/j.neuroimage.2011.09.001
DO - 10.1016/j.neuroimage.2011.09.001
M3 - Article
C2 - 21945466
AN - SCOPUS:83055194328
VL - 59
SP - 1028
EP - 1036
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
IS - 2
ER -