Original scientific paper
Distribution of Major Brain Gangliosides in Olfactory Tract of Frogs
Barbara Viljetić
Ivan Večeslav Degmečić
Vinko Krajina
Tomislav Bogdanović
Ana Mojsović-Ćuić
Domagoj Đikić
Katarina Vajn
Ronald L. Schnaar
Marija Heffer
Abstract
Gangliosides are major cell-surface determinants in the central nervous system (CNS) of vertebrates, found both in neuronal and glial cell membranes. Together with cholesterol and glycosylphosphatidylinositol (GPI) – anchored proteins, gangliosides are involved in organization of plasma membrane microdomains. Based on biochemical studies, frog brain was previously described as having low quantities of gangliosides and their distribution pattern in specific brain regions was unknown. Using highly specific monoclonal antibodies generated against four major brain gangliosides (GM1, GD1a, GD1b and GT1b), we examined the distribution of these molecules in CNS of four different species of frogs (Rana esculenta, Rana temporaria, Bufo bufo and Bufo viridis). We also studied the distribution of myelin- associated glycoprotein (MAG), an inhibitor of axonal regeneration, which is a ligand for gangliosides GD1a and GT1b. Our results show that ganglioside GD1a is expressed in neurons of olfactory bulb in all studied animals. In the brain of Rana sp., GD1a is expressed in the entire olfactory pathway, from olfactory bulbs to amygdala, while in Bufo sp. GD1a is restricted to the main olfactory bulb. Furthermore, we found that most of myelinated pathways in frogs express MAG, but do not express GD1a, which could be one of the reasons for better axon regeneration of neural pathways after CNS injury in amphibians in comparison to mammals.
Keywords
gangliosides; myelin-associated glycoprotein (MAG); membrane microdomains; amphibians
Hrčak ID:
64055
URI
Publication date:
31.1.2011.
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