MRI identification of the rostral-caudal pattern of pathology within the corpus callosum in the cuprizone mouse model.
OBJECTIVE
To characterize and compare histological and MRI-based changes within the corpus callosum (CC) in the cuprizone mouse model of multiple sclerosis (MS).


METHODS
A total of 12 C57/BL6 mice were fed cuprizone from eight weeks of age for four weeks. One cohort of six cuprizone and two control mice were scanned with a T2-weighted (T2W) sequence. The other cohort of six cuprizone and four control mice were scanned using a dual-echo sequence for T2-mapping and a diffusion-weighted sequence with two orthogonal diffusion encoding directions to calculate water diffusivities parallel and perpendicular to the CC fiber (apparent diffusion coefficients [ADC](parallel) and ADC(perpendicular)). After the mice were killed, the rostral-caudal pattern of CC demyelination and other pathologies were examined using Luxol Fast Blue, neurofilament staining, and immunohistochemistry for microglia and were correlated with MRI.


RESULTS
In contrast to control mice, T2W imaging (T2WI) hyperintensity, reduced ADC(parallel), and elevated ADC(perpendicular) were detected in the CC of cuprizone-fed mice, particularly in the caudal segment. The T2 value was increased in the entire CC. Marked demyelination, as well as axonal injury, microglia accumulation, and cellular infiltration were found in the caudal section of the cuprizone mouse CC. The rostral-caudal pattern of abnormalities within the CC in MRI measurements correlated well with histopathological findings.


CONCLUSIONS
Noninvasive MRI using quantitative T2 and ADC mapping accurately characterized the rostral-caudal pattern of CC demyelination and other pathologies in cuprizone challenged mice, and thus could provide an effective way to assess the structural response to experimental therapeutics being designed for the treatment of MS.
Wu
Qi-Zhu
QZ
Howard Florey Institute, University of Melbourne, Victoria, Australia.
Yang
Qing
Q
Cate
Holly S
HS
Kemper
Dennis
D
Binder
Michele
M
Wang
Hong-Xin
HX
Fang
Ke
K
Quick
Melissa J
MJ
Marriott
Mark
M
Kilpatrick
Trevor J
TJ
Egan
Gary F
GF
D000818:Animals; D003337:Corpus Callosum / Q000473:pathology*; D003471:Cuprizone; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000473:pathology*; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D008996:Monoamine Oxidase Inhibitors; D009103:Multiple Sclerosis / Q000139:chemically induced / Q000473:pathology
D008996:Monoamine Oxidase Inhibitors; D003471:Cuprizone