Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities be...

Microglia control excitatory synapses, but their role in inhibitory neurotransmission has been less well characterized. Herein, we show that microglia control the strength of glycinergic but not GABAergic synapses via modulation of the diffusion dynamics and synaptic trapping of glycine (GlyR) but not GABAA receptors. We further demonstrate that microglia regulate the activity-dependent plastic...

Recent findings challenge the concept that microglia solely function in disease states in the central nervous system (CNS). Rather than simply reacting to CNS injury, infection, or pathology, emerging lines of evidence indicate that microglia sculpt the structure of the CNS, refine neuronal circuitry and network connectivity, and contribute to plasticity. These physiological functions of microg...

Single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate in cytotoxic levels within organs of various animal models and cell types, which emerge as a wide range of promising biomedical imaging. Septic encephalopathy (SE) is an early sign of sepsis and associated with an increased rate of morbidity and mortality. Microglia activation plays an important role in neuroinflammation,...

Over the last decade, the concept and nomenclature of microglial phenotype polarization has been carried over from the peripheral macrophage literature. However, it is not entirely correct to view these two cell types as overlapping. Microglia, although related to macrophages, have several differences and their own unique repertoire of features. In particular, microglia arise from a distinct ea...

To investigate differences among brain-derived microglia and other classes of immune cells, we compared the morphologies and growth properties of mononuclear phagocytes isolated from tissues of the newborn rat. Scanning EM shows that microglia from postnatal rat brain are covered with spines (typically > 20 per cell body) in a distinctive manner which contrasts the smooth surfaces of bone marro...

A precise knowledge of the early events inducing maturation of resting microglia into a competent APC may help to understand the involvement of this cell type in the development of CNS immunopathology. To elucidate whether signals from preactivated T cells are sufficient to induce APC features in resting microglia, microglia from the adult BALB/c mouse CNS were cocultured with Th1 and Th2 lines...

PURPOSE To determine whether donor-derived microglial cells play a role in dictating the immunogenicity of immature neuronal retinal tissue transplanted intraocularly. METHODS Neonatal neural retinas (aged <24 hours) from C57BL/6 or BALB/c mice were implanted in the anterior chamber or the subretinal space of adult syngeneic or allogeneic eyes. After 12 and 35 days of engraftment, retinal gra...

Microglia in the brain and macrophages in peripheral organs are cell types responsible for immune response to challenges. Indoleamine 2,3-dioxygenase 1 (IDO1) is an immunomodulatory enzyme of the tryptophan pathway that is expressed in the brain. The higher activity of IDO1 in response to immune challenge has been implicated in behavioral disorders. The impact of IDO1 depletion on the microglia...

Minocycline, a tetracycline with anti-inflammatory properties, has been reported to down-regulate the activity of microglia, whose activation occurs in inflammatory and degenerative diseases of the central nervous system, such as multiple sclerosis and Alzheimer's disease. In these disorders, a T cell component is also evident, and we have demonstrated previously that the interaction of activat...