Effects of undernutrition during early life on granule cell numbers in the rat dentate gyrus

Abstract

Undernutrition during early life is known to affect the morphology of the hippocampal formation. Recent advances in stereological techniques have made it possible to make relatively unbiased estimates of total cell numbers in well-defined brain regions. It was decided to use these methods to determine the effects of different levels of undernutrition during early postnatal life on the granule cells of the rat dentate gyrus. Male hooded Long Evans rats were undernourished between the 16th day of gestation and 30 postnatal days of age to two different levels. The daily food intake of level-1 and level-2 rats represented about 60 and 40%, respectively, of that eaten by well-fed, age-matched controls. Nutritional rehabilitation of the rats was commenced when they had reached 30 days of age by placing them on an ad libitum diet. Groups of control and experimental rats were killed at 70 and 212 days of age. The Cavalieri principle was used to determine the granule cell layer volume within the dentate gyrus, and the "dissector" method was used to determine numerical densities of these granule cells. These estimates were used to calculate the total numbers of granule cells. There were between 260,000 and 320,000 granule cells within the dentate gyrus of 70-day-old control and experimental rats. By 212 days of age, well-fed controls had an average of about 834,000 granule cells. The level-1 and level-2 previously undernourished rats had about 515,000 and 595,000 granule cells, respectively. Two-way analysis of variance procedures showed significant main effects of nutrition and age as well as a significant interaction between them.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic effects of early protein undernourishment and renourishment in wistar rats

“…It is known that protein or protein-calorie undernourishment affects different organs and systems by either direct (cellularity and function) or indirect (growth and organism development) involvement, both in humans and in well-controlled experimental models (BAPTISTA JS et al, 2013;BEDI, 1991;GOMES et al, 2006;MONTE, 2000). Understanding the metabolism of animals subjected to malnutrition elucidates many aspects of this complex syndrome, helping scientists and health professionals with reliable data on the evolutionary, functional and morphological impairments, and on recovery from the disease.…”

Effects of combined pre- and post-natal protein deprivation on the myenteric plexus of the esophagus of weanling rats: A histochemical, quantitative and ultrastructural study

“…Macroscopically, there is an indication that in the central nervous system (CNS) that cortical thickness itself is more affected by malnutrition than the cerebrum as a whole [29] . Nevertheless, if the severe malnutrition causes nerve cell loss in some regions of the CNS (e.g., dentate gyrus) [30] , the cerebral cortex seems protected from neuronal loss [31] . Previous data concerning malnutrition on the ENS of rats is also conflicting: there is evidence showing that it determines a decrease in the number of myenteric neurons in the jejunum [1] , a increase of these cells in the small intestine as a whole [4] or yet does not alter the number of myenteric neurons in the colon of protein-deprived young animals [3] .…”

Nutritional Regulation of IGF-I Expression during Brain Development in Mice

“…In rodents, undernutrition during early life results in reduced brain weight, reduced total cell number, reduced and delayed myelination, increased density of cortical neurons, loss of axon terminals in the cerebral cortex, and substantial deficits in the synapse-to-neuron ratio in some brain regions, indicating a reduction in the total synapse number (1)(2)(3)(4)(5)(6)(7). In addition to the duration and severity of undernutrition, the developmental time when undernutrition occurs is crucial to the degree of injury (1,2,8).…”