Microglia in the Monkey and Rabbit Retina

Microglial responses to focal lesions of the rabbit retina: Correlation with neural and macroglial reactions

“…In the normal rabbit retina there is debate as to whether there is a complete population of microglia throughout the OPL which in some cases do not express NDP-ase or whether the NDP-ase accurately reflects the OPL population (Boycott and Hopkins, 1981;Hume , 1983;Schnitzer, 1989;Terubayashi et al, 1984;Vrabec, 1970). We have recently demonstrated that different strains of rabbit have quite different numbers of NDP-ase positive microglia in the OPL, ranging from a complete coverage to only rare cells, as in the strain used in the current study (Humphrey and Moore, 1995).…”

Embryonic and postnatal development of microglial cells in the mouse retina

“…The distribution of microglial cells in the adult retina has been described in fish (Dowding et al, 1991;Salvador-Silva et al, 2000), amphibians (Goodbrand and Gaze, 1991), birds (Navascués et al, 1994;Won et al, 2000;Cuadros et al, 2006), and mammals, including rabbits (Ashwell, 1989;Schnitzer, 1989;Humphrey and Moore, 1996), mice (Zhang et al, 2005b), rats Harada et al, 2002;Zhang et al, 2005a), monkeys (Vrabec, 1970;Boycott and Hopkins, 1981), and humans (Penfold et al, 1991(Penfold et al, , 2001Provis et al, 1995;Yang et al, 2000;Gupta et al, 2003). It has been observed in these species that microglial cells in the adult normal retina appear in the ganglion cell layer (GCL) and all fibrous layers, whereas they are scarce in the inner nuclear layer (INL) and absent in the outer nuclear layer (ONL).…”

Retinal Microglia in Cases of Choroidal Melanoblastoma

“…3). Within the inner layers of the retina the picture of microglial elements does not differ from normal except for their number: They arc rather rare -especially in the third case -where we found only few of them along the capillaries at the boundary between the inner nuclear and inner plexiform layer, where they are plentiful in a normal retina [12). It would seem likely that many of them moved to the outer surface of the retina.…”

“…In such a case, their long axis is oriented perpen dicularly to the outer retinal surface. Under normal conditions they are situated with their long axis parallel to the surface, accumulating at the line of synapses within the outer plexiform layer [12]. The expansions of such displaced elements in melanoblastomas penetrate between the outer segments of receptors, sometimes a whole microglial cell being found an intensively stained microglial element in a flat section through the outer nuclear layer.…”

“…Several authors tried to study the reactions of the retinal microglia to various pathologic conditions [11,[13][14][15]. However, even until the present time some doubts persisted about the existence of retinal microglia in normal conditions [12], In the last time, opinions about the microglia in general arc changing [3]. We decided, therefore, to follow the reactions of micro glial elements in the retina in cases of human choroidal melanoblastoma, where the first moderate changes concern only the outermost parts of retinal receptors.…”