Abstract
Purpose : It has been reported that exercise reduces activation of cytotoxic microglia, thereby, ameliorating neurodegeneration in Alzheimer's disease. We aimed at studying if that is also the case in spinocerebellar ataxia (SCA) model mice. Method : We quantified numbers of IbaI-positive microglia and/or CD68-positive cytotoxic microglia in the cerebellum of wild type (WT), SCA type1 knock in (SCA1-KI), SCA type3 transgenic (SCA3), heterozygous Staggerer (+/sg ) and homozygous Staggerer (sg/sg) mice with or without exercise. Rotarod test was used for exercise. Result : Proliferation of IbaI-positive microglia was found in SCA3 and sg/sg mice without exercise. Exercise differentially changed the number of IbaI-positive microglia in SCA3 and sg/sg. The number was decreased in SCA3 mice, whereas, increased in sg/sg mice after exercise. CD68-positive cytotoxic microglia, which was selectively found in sg/sg, was also increased in sg/sg mice after exercise. Conclusion : Exercise differentially affected numbers of microglia in SCA model mice. Thus, exercise might not always suppress activation of cytotoxic microglia. It is advisable to search for an optimal type of exercise that fits well with a patient to accomplish suppression of cytotoxic microglia.
