Genetic manipulation of microglia during brain development and disease

Microglia are unique cells in the central nervous system (CNS) and of particular importance for the development and homeostasis thereof. Recently, genetic manipulation of microglia in vivo has led to valuable insights about the origin of microglia and their behavior under steady-state conditions. Nevertheless, in pathological settings, their resting and surveillant nature can rapidly turn into either a beneficial or detrimental state significantly shaping disease courses. Therefore, it is tempting to manipulate these cells under pathological conditions in vivo and thereby decipher their contribution to the outcome of frequent neurological diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS). In this review, we will discuss which transgenic mouse models are currently available and can thus be used to genetically label microglia, to modulate their gene expression or to deplete them during development and under healthy conditions. Furthermore, the hallmarks of neurological disease models and how genetic manipulation of microglia will expand our knowledge about the underlying disease mechanisms will be discussed. This article is part of a Special Issue entitled: Neuro Inflammation edited by Helga E. de Vries and Markus Schwaninger. (C) 2015 Elsevier B.V. All rights reserved.