Macrophages and microglia in the nervous system

The origin and differentiation of microglial cells during development

“…These events were described by del Rio-Hortega (1932), and received later support from morphological observations of intermediate forms between ameboid and rami®ed microglial cells (Ling, 1981;Perry et al, 1985;Leong and Ling, 1992;Wu et al, 1992Wu et al, , 1993Cuadros et al, 1994). The transformation of ameboid microglia into rami®ed microglia is now largely accepted (Perry and Gordon, 1988;Ling and Wong, 1993;Davis et al, 1994;Barron, 1995). In vitro studies have shown that cultured microglial cells become rami®ed under certain conditions, such as culture on astrocyte monolayers (Sievers et al, , 1996Tanaka and Maeda, 1996), when certain factors are added to the culture medium (Suzumura et al, 1991;Giulian et al, 1995;Fujita et al, 1996;Eder et al, 1997), and in the presence of certain extracellular matrix molecules Giulian et al, 1995).…”

GM1 induces p38 and microtubule dependent ramification of rat primary microglia in vitro

“…Because their morphological changes are related to physiologically important activities (Giulian and Baker, 1986;Perry and Gordon, 1988;Streit and Kreutzberg, 1988), it is important to identify factors that can influence their morphological changes in order to understand the behavior of microglia in physiological and pathological events. In the present study, we observed that Gmix induced ramified morphological changes in cultured rat primary microglia, which were different from those induced by other agents, such as LPS or IFN-γ, and that the effect of Gmix on the ramified morphological changes of microglia was due to GM1, one of the gangliosides in Gmix.…”

“…These ramified microglia can be transformed into the ameboid type when pathologically stimulated in vivo (Akiyama et al, 1988;Flaris et al, 1993;Streit and Kreutzberg, 1988). Since the morphological change of microglia has been shown to be linked to functional phenotypes both in vivo and in vitro (Giulian and Baker, 1986;Perry and Gordon, 1988;Streit and Kreutzberg, 1988), the elucidation of mechanisms involved in their morphological changes is of potential clinical importance. Nevertheless, in vitro studies on ramified microglia have been hampered because microglia isolated from primary cultures of neonatal rat cerebral cortex are more highly transformed than ramified microglia of the normal central nervous system (CNS) (Giulian and Baker, 1986).…”

Microglia/Macrophages Migrate through Retinal Epithelium Barrier by a Transcellular Route in Diabetic Retinopathy

“…5 Microglial cells, the main resident sentinel immune cells, are located in the inner part of the retina, around vessels in the healthy retina. [7][8][9][10][11][12] These cells become activated and migrate in the subretinal space in several retinopathies such as diabetic retinopathy, 13,14 age-related macular degeneration, 15 and aging. 5,16,17 The activation of microglia induced by hyperglycemia has been associated with the early development of DR.…”