Emerging roles of microglia cells in the regulation of adult neural stem cells.

Microglia cells were first described as a component for the brain with few beneficial functions. The classical point of view implied that these cells had inflammatory properties more than benefits for brain homeostasis. To date, this assumption has changed and new roles of microglia cells are continuously discovered. Although, the main function of microglia cells is to provide a cellular defense against harmful or pathogen agents (bacteria, viruses, fungi, toxins, etc.), recent evidence indicates that microglial cells are dynamic modulators of synaptic pruning, brain development and neurogenesis by maintaining a balance of local cell population. In this commentary, we summarized the emerging role of the relationship between microglia cells and the neural stem cells resident in the ventricular-subventricular zone (V-SVZ), the largest neurogenic niche in the adult brain.