[Roles of Microglia in Neurodegenerative Diseases].

Recent advances in glial research have elucidated the roles of microglia under various contexts in health and disease. Microglial activation used to be considered only as a consequence of neuronal damage. However, a series of studies using mouse models of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease selectively affecting motor neurons, indicated that microglia actively influence the disease course. In this review, we summarize the growing evidence that microglia play a critical role in the survival and demise of motor neurons in ALS. These observations suggest microglia as a promising therapeutic target of neurodegenerative diseases.