Fetal Undernutrition Research Articles

Vulnerability of developing brain. V. Effects of fetal and postnatal undernutrition on regional brain enzyme activities in three-week-old rats.

Extract: Normal and undernourished 3-week-old rats were examined for activity of crude mitochondrial acetylcholinesterase (a marker for nerve-ending particles) in four brain areas. Littermates of these animals were used for determination of four other brain enzymes which are known to increase in activity during rat brain growth. Significant deficits (in units per gram wet weight) in crude mitochondrial acetylcholinesterase activity were found in the forebrain (normal = 2085, malnourished = 1444), brainstem (normal = 709, malnourished = 536), and olfactory lobes (normal = 74, malnourished = 46) of undernourished animals. When enzyme activities were expressed in terms of tissue wet weight, whole brain butyrylcholinesterase, fumarate hydratase, and β-galactosidase were found to be unaffected by undernutrition, whereas 5'-nucleotidase activity was higher in undernourished (730 units/g dry weight) than in control animals (660 units/g dry weight). The results lend support to the hypothesis that those constituents of the brain which show a large increase in concentration during brain growth are those most likely to be affected by growth retardation in early life. Speculation: Undernutrition during the period of rat brain growth when interneuronal connectivity is being established may result in a deficit in the number of nerve-ending particles in the brain. This could imply that an impaired formation of synaptic connections may account for some of the functional changes which result from growth restriction at this time.

Vulnerability of developing brain. VI. relative effects of foetal and early postnatal undernutrition on reflex ontogeny and development of behaviour in the rat

Mother rats were either fed ad libitum or undernourished for much of pregnancy and throughout lactation. Their offspring were cross-fostered at birth, such that the young were nutritionally deprived during only one period, either gestation or the suckling period. The growth and development of these rats were compared with those of rats from an earlier investigation which were fully fed or undernourished during both periods. Food restriction during gestation caused a 10% deficit in birth weight, but from the fifth postnatal day the growth rate was almost entirely determined by the postnatal nutritional regime. The effect of nutritional deprivation during gestation on reflex ontogeny and the development of physical features was negligible, while that of postnatal underfeeding was highly significant with respect to most characteristics maturing after day 10. Only the appearance of certain aspects of exploratory behaviour showed evidence of being retarded by gestational restriction. Nutrition during the suckling period was a major determinant of the frequency of upward responding in the open field. Balancing ability at 21 days tended to be impaired in rats underfed during the suckling period. The results are discussed in relation to the vulnerable period hypothesis of brain growth and development and its application to the human species.

Metabolism of volatile fatty acids by liver and portal-drained viscera in sheep.

Metabolism of volatile fatty acids by liver and portal-drained viscera in sheep.

INTRA-UTERINE UNDERNUTRITION AND BRAIN DEVELOPMENT

The guinea pig, like the human, initiates the period of rapid brain growth in utero and thus provides a model for measuring the effects of maternal malnutrition on intra-uterine brain growth. In these studies the newborn of undernourished guinea pig mothers showed significant reductions in body weight and brain weight, cellularity, protein, cholesterol, cerebroside, and sulfatide contents. The reductions in wet brain weight and protein content were significant for cerebellum but not for cerebrum. Animals undernourished in utero and fed normally after birth showed normal whole brain weight, cerebroside and sulfatide contents, and normal cerebrum cellularity by adulthood. However, the type of cells increasing in the cerebrum during postnatal rehabilitation is unknown. Wet weight and cellularity were still diminished by 22% and 17%, respectively, in the adult cerebella. The results suggest that adequate postnatal nutrition will offset some, though not all of the brain biochemical changes resulting from fetal undernutrition.