Microglia Roles in Synaptic Plasticity and Myelination in Homeostatic Conditions and Neurodevelopmental Disorders

Microglia are the immune cells of the brain, involved in synapse formation, circuit sculpting, myelination, plasticity, and cognition. Being active players during early development as well as in adulthood, microglia affect other cells directly by their long processes and unique receptors and indirectly by secreting growth factors and cytokines. In this review, we discuss the roles of microglia in neurodevelopmental disorders, synaptic plasticity, myelination, and homeostatic conditions throughout human and mouse development. Within these processes, we specifically focus on the contribution of altered microglial interactions with neurons and oligodendrocytes, altered cytokine and growth factor activities, and alterations in the complement system. We conclude by highlighting future perspectives and providing an overview of future research on microglia.