Abstract
Gangliosides have been measured in three parts of the brain (forebrain, cerebellum and brainstem) in three species namely man, the pig and the rat at different stages of normal development. Sub fractionation of gangliosides into the four major types was carried out in each brain part by thin-layer chromatography. DNA content was studied as a measure of cellularity. Samples of the three brain parts from malnourished children were studied. Brain parts from pigs undernourished prenatally (runts) and pigs malnourished postnatally (protein deficient or calorie deficient) and also from animals rehabilitated for different periods of time were included in this study. The brain of rats undernourished postnatally and of the offspring of rats reared from weaning on a moderately low protein diet and also those of the offspring of rats which were on a low protein diet during gestation and lactation were used in this investigation. The studies of the ganglioside content of the three parts of the brain of normal pigs and rats showed that there are differences in the pattern of development in each part. In the development curve for the forebrain, there were two peaks in both species. However, there was an overall similarity in the pattern for each of the brain parts in these two species. The large difference was in the timing of the first peak in the curve for the forebrain. In all three species, the principal ganglioside in the forebrain was a disialoganglioside, G[3], and that in the cerebellum was the trisialoganglioside, G[1]. The ganglioside content was found to be low for the chronological age in all three parts of the brain of the malnourished children and animals; the value was particularly low for weight in the forebrain of malnourished children, the cerebellum of the undernourished pigs and the brainstem of the severely malnourished rats. Incorporation of [14]C-glucosamine into the brain gangliosides of the severely malnourished rats, in vivo, resulted in a low total activity compared to the controls. The G3 ganglioside, which normally accounts for the largest proportion of the major gangliosides in the forebrain, was proportionally reduced considerably in the forebrain of malnourished children. Rehabilitation for different periods of time did not particularly correct the ganglioside content of the cerebellum in the undernourished pigs.