Immunostaining of ganglioside GD1b, GD3 and GM1 in rat cerebellum: Cellular layer and cell type specific associations

We have studied the cellular distribution of gangliosides GD1b, GD3 and GM1 in rat cerebellum by immunostaining, using monoclonal antibodies and confo cal microscopy. Antibodies against astroglial, neuronal and synaptic vesicl e associated molecules were used for colocalization analyses. In the gray m atter, the anti-GD1b antibody stained thin strands in the molecular layer ( ML), interpreted as Bergman glia fibers based on colocalized staining with anti-glial fibrillary acidic protein (GFAP), The neuropil in the granule (G L) and Purkinje (PL) cell layers was also anti-GD1b positive. The anti-GD3 antibody stained the ML, the neuropil in the GL and PL and also the granule and Purkinje cell bodies, appearing intracytoplasmically and vesicle assoc iated. Anti-GD1b and anti-GD3 staining in the GL glomeruli were colocalized with anti-synaptophysin staining. The anti-GM1 antibody stained cell bodie s in the ML but they could not be characterized in colocalization experimen ts. The GL and PL were not stained with the anti-GM1 antibody. In the white matter, different staining patterns were seen for the gangliosides, the an ti-GM1 staining being the most intense. This study shows cellular layer and cell type specific associations of the investigated gangliosides and local ization of GD1b and GD3 at synaptic sites, warranting further studies on th eir role in synaptic mechanisms. (C) 2000 Wiley-Liss, Inc.