Brain gangliosides during the life span (embryogenesis to senescence) of the rat.

The concentration of gangliosides, sialoglycoproteins and proteins was studied in the whole brains and single brain structures (cortex, olfactory bulb, corpora quadrigemina region equals midbrain, cerebellum, thalamic region and oblongated medulla) of female rats from 14 developmental stages ranging from day 8 of gestation to more than 3 years of age. The content of protein- and ganglioside-bound neuraminic acid showed a peak at 3 weeks of age and then decreased with aging, whereas that of proteins increased until senescence. All over the life span the developmental profiles of 12 individual gangliosides in the different brain structures (cortex, corpora quadrigemina region approximately midbrain, cerebellum, thalamic region, medulla) and in whole brain samples were followed. There are distinct differences between the brain structures. Additionally each brain region is characterized by specific developmental ganglioside profiles. However, some ganglioside changes are common to all regions: GD3 in general is a marker for cell division and migration, whereas the polar ganglioside fractions GQ1b and GP1 are characteristic for nerve cell sprouting and arborization. Especially in the cortex GD1a seems to be the marker for synaptogenesis and GM1 and GM4 for myelination. The results were discussed in view of the main morphological patterns of differentiation.