Objective　　 To investigate the changes of cerebral cortex volume and myelinated fibers in the cerebral cortices of cuprizone(CPZ)-induced schizophrenia-like mice. 　　Methods　　 Six-week old male C57BL/6 mice were divided into a CPZ group and a control group. The mice in the CPZ group were fed with mixed standard rodent chow containing 0.2% CPZ

while those in the control group were fed with standard lab chow. After six weeks

behavioral tests were performed to confirm the success of schizophrenia-like animal model. Then the cerebral cortex volume and myelinated fibers in the cerebral cortices were determined with transmission electron microscopy and stereological methods. 　　Results　　 Mice in the CPZ group showed schizophrenia-like performance. Stereological results showed that there was no significant change in the volume of the cerebral cortex between CPZ group and control group (P0.05). Compared with the control group

the length density and total length of myelinated fibers in the cerebral cortices of the CPZ group significantly decreased by 64.3% and 68.9%

respectively (P0.01). Compared with the control group

the mean diameter of myelinated fibers in the CPZ group significantly increased by 17.8% (P0.01)

and the total length of the myelinated fibers with diameters of 0.2 to less than 0.4 μm

0.4 to less than 0.6 μm and 0.6 to less than 0.8 μm significantly decreased by 4.317

3.313 and 0.940 km

respectively (P0.01). There was no significant difference in the total length of other myelinated fibers between the two groups. 　　Conclusion　　 In CPZ group

the total length of myelinated fibers in cerebral cortex decreases but the mean diameter of the myelinated fibers increases

which is due to the loss of small-diameter myelinated fibers.