Objective      To study the effect of cuprizone (CPZ)-induced demyelination on callosal oligodendrocytes and motor function in C57BL/6 mice.       Methods      Six-week old male mice fed with normal diets served as a control group and 6 week old male mice fed with mixed diets containing

0.2% CPZ for 6 weeks served as an experimental group. Demyelination in central nervous system was induced. Demyelination in cerebral callosal region was identified with luxol fast blue (LFB) and myelin structural protein(MBP) immunohistochemical staining. Stability and reliability of the established model were assayed. Demyelinated callosal oligodendrocytes were observed with MBP+CC1 double immunostaining. Overall function of mice was observed by monitoring their body weight. Characteristics of motor function in cerebral callosal region were observed with behavioral tests (Rotarod and open-field test).       Results      The demyelination in cerebral callosal region was noticeable and the MBP level was significantly lower in experimental group than in control group (0.395±0.019vs0.242±0.016

P0.01) 6 weeks after induction of demyelination. Image and statistical analysis showed that the number of CC-1

+

was parallelly decreased with myelin protein of MBP

+

[(42.62±2.48)/100 μm

2

vs(25.04±3.68)/100 μm

2

P0.05

]

. The body weight was increased in control group but decreased in experimental group

which then became stable and gradually recovered. Behavioral experiments showed that the motor coordinating function and spontaneous activity were significantly lower in experimental group than in control group (Rotarod test: 156.17±22.17vs78.50±7.80; Open-field test: 240.91±29.52vs163.31±21.05; P0.05). However

no significant difference was found in exploration behavior of mice (3.7%/5.4%vs3.6%/5.3%

P0.05).       Conclusion      CPZ-induced demyelination is related with the loss of oligodendrocytes in mice and mainly influences their motor coordinating function and spontaneous activity but not their senior function of exploration behavior.