Objective       To investigate the changes of the myelinated fibers in the corpus callosum of the cuprizone (CPZ)-induced mouse model of schizophrenia

and the relationship between the demyelination changes and the behavioral abnormalities in this animal model.       Methods       Nineteen male C57BL/6 mice were randomly divided into 2 groups

control group (n=10) and  CPZ-treated group (n=9).The mice in

the later group were fed with a diet of 0.2% (w/w) CPZ mixed into standard rodent chow for 6 weeks. The mice in control group were fed standard lab chow and lab water. The behavioral changes of the animals were investigated with a series of behavioral tests. The changes of the corpus callosum and the myelinated fibers in the corpus callosum were studied with immunohistochemical assay

transmission electron microscopy and stereological methods.       Results      The CPZ-treated mice displayed more activities in the central area of open field （P＜0.05）and in the open arms of elevated plus maze（P＜0.05）

which suggested that the anxiety behavior in the CPZ-treated mice was reduced when compared to the control. Morris water maze demonstrated that there was no working memory deficit in the CPZ-treated mice compared to the control（P＞0.05）. There was no abnormality in the motor function and basic exploration ability in the CPZ-treated mice when compared to the control. There were demyelination changes in the corpus callosum of the CPZ-treated mice. There was no significant difference in the total volume of the corpus callosum between the CPZ-treated mice and the control（12.66±1.07 vs 13.53±2.79 mm

3

）. The length density and total length of the myelinated fibers in the corpus callosum were significantly decreased in CPZ-treated mice than control mice（0.70±0.17 vs 1.47±0.17 km/mm

3

9.06±2.56 vs 19.75±3.70 km

P0.05）.       Conclusion      CPZ-treated mice display schizophrenia-like behaviors and demyelination change in the corpus callosum.