Naslov
Gangliosides are raft building constituents of paleocortex in amphibians

Autori
Viljetić, Barbara ; Bogdanović, Tomislav ; Mojsović, Ana ; Đikić, Domagoj ; Heffer-Lauc, Marija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Congress of the Croatian Society of Biochemistry and Molecular Biology with international (HDBMB 2008) : book of abstracts / Strelec, Ivica ; Glavaš-Obrovac, LJubica - Zagreb : Hrvatsko Društvo za Biotehnologiju, 2008

ISBN
978-953-95551-2-0

Skup
Kongres Hrvatskog društva za biokemiju i molekularnu biologiju

Mjesto i datum
Osijek, Hrvatska, 17.09.2008. - 20.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
gangliosides; myelin- associated glycoprotein; rafts

Sažetak
The major four gangliosides (GD1a, GD1b, GT1b and GM1) in mammalian brain are ten times more abundant then in any extra neuronal tissue. All mammalian brains also show very similar distribution ; GD1a, GD1b and GT1b are presenting in virtually all neuronal and astroglial plasma membranes, while GM1 characterize advanced stages in oligodendrocyte maturation. Gangliosides function as (1) organizers of lipid domains in outer membrane leaflet, (2) modulating receptors during signaling, or (3) as ligands themselves, in the case of GD1a/GT1b interaction with receptor MAG (marker of mature myelination). It is not clear which one of these functions preceded during evolution of brain. To get some insight in this problem, we examined frog brain, previously described as having low quantities of all glycosphingolipids. We extracted gangliosides from brains of six frogs (species Rana esculenta). Out of four major gangliosides, we found just GD1a and GD1b. GD1a is proved to be the ligand for oligodendrocyte receptor MAG, while GD1b is weak ligand of the same receptor. On paraformaldehide fixed brains, using immunohistochemistry for MAG and four major gangliosides, we established presence of just GD1a and GD1b. We also proved that amphibian brain oligodendrocytes do express MAG, unlike fish, but do not express GM1, as mammals do. Both, GD1a and GD1b are presented just on neurons of paleocortex, marking the entire olfactory pathway, from olfactory bulbs toward amygdale. This pathway is engaged in seasonal and mating behavior. Because both gangliosides (GD1a/GD1b) are presented on the same neurons, we presume that function of raft building preceded the ligand function in the case of amphibian brain. Olfaction is more important than vision, or any other sensory clue, to the frog and it is of particular neurobiological importance that glycosphingolipids are evolutionary present first as raft constituents in the olfactory pathway, while reptiles, birds and mammals have gangliosides in whole brain.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Temeljne medicinske znanosti

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