Ganglioside changes in the chicken optic lobes as biochemical indicators of brain development and maturation

The development profiles of 16 different gangliosides of the optic lobes of the chicken were followed from the sixth day of incubation to the tenth posthatching week and correlated to known morphological development. Several, previously undetected novel fractions occurred between the sixth and the tenth embryonic days. According to their migration rates on TLC-plates 4 of them may be GT3, GT2, GT1c, GQ1c. Three even more slowly migrating fractions represent penta-, hexa-, and septa-sialogangliosides. At the sixth day of incubation, characterized by maximal proliferation of neuroepithelial cells, the optic lobes contained predominantly GD3. Up to the eleventh day of incubation, parallel to decreased mitotic activity, maximal cell migration and neuron differentiation, GD3, GD2, and GT3 decreased in favor of newly detected polysialogangliosides. Thereafter, up to handling, parallel to increased growth and arborization of dendrites and axons as well as synaptogenesis, the newly detected polysialogangliosides decreased in favor of GD1b, GT1b, GQ1b, and GD1a. At hatching the myelin-specific GM4 appeared, reaching about 8% of total ganglioside sialic acid after 10 weeks. Likewise a fraction, migrating somewhat faster than GM1, increased. This band, named GM1', is suggested to be also myelin-associated. The other monosialogangliosides were always minor fractions, none exceeding 4% of total ganglioside sialic acid.