Microglial cells in the brain of Pleurodeles waltl (Urodela, Salamandridae) after wallerian degeneration in the primary visual system using Bandeiraea simplicifolia isolectin B4-cytochemistry.
In the brain of the salamander Pleurodeles waltl, microglial cells were investigated cytochemically with isolectin B4 (IB4) of Bandeiraea simplicifolia after optic nerve transection and during subsequent regeneration. Double-labeling with an antibody directed against the glial fibrillary acidic protein of astrocytes revealed no immunoreactivity in microglial cells and confirmed the absence of non-radial, free astroglial cells in the tectum. After two days, IB4-labeled microglial cells began to populate the rostral parts of the primary visual system. The origin of these early vimentin-immunoreactive microglial cells seemed to be mainly IB4-labeled cells in a perivascular position and meningeal macrophages. After 12 days, microglial cells infiltrated the tectum in four layers: one in the ependyma, one in the outermost periventricular grey, and two in the degenerating visual neuropil where activated microglial cells displayed a ramified morphology. After 3 weeks, microglial cells accumulated within the degenerating neuropil while reducing their processes. After 7 weeks, the number of microglial cells was still increased on the affected side. The subarachnoid space above the neuropil where regenerating retinal afferents arrived was filled with IB4-labeled macrophages. Only very few microglial cells were seen in co-existence with Müller cells in the lesioned and intact retinae, whereas microglial cells and macrophages were IB4-labeled in the optic nerve head and at the ora serrata.
Naujoks-Manteuffel
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Institute of Brain Research, University of Bremen, Germany.
Niemann
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U
D000818:Animals; D001921:Brain / Q000166:cytology*; D003714:Denervation; D007150:Immunohistochemistry; D037102:Lectins; D017628:Microglia / Q000166:cytology*; D009416:Nerve Regeneration; D009900:Optic Nerve / Q000166:cytology; D037121:Plant Lectins; D010999:Pleurodeles / Q000033:anatomy & histology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D014795:Visual Pathways / Q000166:cytology*; D014855:Wallerian Degeneration
C045475:Griffonia simplicifolia lectins; D037102:Lectins; D037121:Plant Lectins