Microglial cells in the brain of Pleurodeles waltl (Urodela, Salamandridae) after wallerian degeneration in the primary visual system using Bandeiraea simplicifolia isolectin B4-cytochemistry

• Published in: Glia Vol. 10; no. 2; p. 101
• Main Authors: Naujoks-Manteuffel, C, Niemann, U
• Format: Journal Article
• Language: English
• Published: United States 01.02.1994
• Subjects: Animals; Brain - cytology; Denervation; Immunohistochemistry; Lectins; Microglia - cytology; Nerve Regeneration; Optic Nerve - cytology; Plant Lectins; Pleurodeles - anatomy & histology; Retinal Ganglion Cells - physiology; Visual Pathways - cytology; Wallerian Degeneration
• ISSN: 0894-1491
• DOI: 10.1002/glia.440100204

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.