Introduction

Abstract

Microglia are taking a central role in the Neuroscience arena nowadays, following a series of recent discoveries challenging their traditional portrayal as simple brain macrophages. Indeed, microglia have unique properties compared with other cells of the immune system, including their origin from the embryonic yolk sac, their capacity for self-renewal, and the extreme motility of their processes which closely interact with all the neighboring elements of the nervous parenchyma. In parallel, we have just begun to unravel novel roles for microglia during normal physiological conditions that are impacting our understanding of their crucial participation in pathological situations. Throughout the chapters of this book, some of the most intriguing open questions in microglial research today are transversally discussed. How is microglial population homeostasis maintained? Are there heterogeneous subpopulations of microglia? Can microglia respond to neuronal activity, and alter it? Do microglia interact with other types of immune cells? Are microglia beneficial or detrimental in diseases of the central nervous system? Are there novel tools to specifically manipulate microglia in a non-invasive manner? We do not have the answers yet for most of these questions, but in the next few years their investigation will will undoubtly continue to shape the future of Neuroscience in unexpected manners.