Effects Of ICV Sphingomyelin On Movement And Behavior In Mice

Parkinson's disease(PD)is a common neurodegenerative disease.The symptoms include motor dysfunction and behavioral disorders,but its mechanism is to be studied.Lipid metabolism disorders may participate in the abnormal performance of PD.Sphingomyelin(SM)is the main ingredient of brain myelin sheath.Ceramide(Cer)and SM have similar structures and are important signaling molecules.These lipid metabolism disorders in the brain might lead to abnormal movements and behaviors in animal models.Therefore,by intracerebroventricular SM or Cer in mice,I tested the corresponding changes in animal movements and behaviors as the effect of SM or Cer on brain dysfunction with reference to PD and its potential underlying mechanism.Using the C57/B6 J strain of mice aged 10 months,equal numbers of male and female animals were injected with SM or Cer,icv.The behaviors of mice were compared with those before the injection at different time.Through mating behavior,open field test and other tests,their behaviors of potential impulse control disorder(ICD)and anxiety were detected.Their changes in the motor function were investigated by the rotarod test.These behavioral investigations could partially provide evidence to reflect some characteristics of PD,and help to analyze possible change and effect of sphingolipid metabolism in PD model of mice.The study found that male mice had the dyskinesia of motor balance disorder after the injection of SM into the ventricle,but did not have significant ICD behavior.After the injection of Cer,male mice had the dyskinesia of motor balance disorder,increased mating activity,anxiety and reduction in motor ability.However,after the injection of the same dosages of sphingolipids,female mice did not have these PD-like behaviors.I tested the behaviors of female mice in a time course within one week after the injection and found that female mice did not have the PD-like behaviors in response to ICV SM or Cer.The experimental results showed that ICV SM or Cer in the brain of mice would lead to abnormal movements and behaviors of male mice potentially reflecting the phenotype characteristic of PD.The behaviors of female mice were not affected by the content of sphingolipid,suggesting the gender difference between male mice and female mice.This model can further provide the theoretical basis for the pathogenesis of sphingolipid in some PD model in mice.