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Updated: Jul 30, 2026
Neurodevelopmental Reflex Testing in Neonatal Rat Pups
Published on: April 24, 2017
Late effects of early nutritional manipulations
O Koldovský1, P Hahn, M Hromadová
1Department of Pediatrics, University of Arizona, Tucson, USA.
Insights
Early life interventions like premature weaning or dietary changes in rats significantly impact adult metabolic health, affecting cholesterol, hormones, and body composition. These findings highlight the long-term consequences of neonatal experiences on later-life health.
Area of Science:
- Endocrinology
- Metabolic Health
- Developmental Biology
Background:
- Neonatal interventions can have lasting effects on adult physiology.
- Early life nutrition and stress exposure are critical determinants of long-term health outcomes.
- Understanding these early-life effects is crucial for preventing metabolic diseases.
Purpose of the Study:
- To investigate the long-term metabolic consequences of early neonatal interventions in rats.
- To examine the effects of premature weaning and altered litter size/diet on adult metabolic parameters.
- To explore the relationship between early life experiences and later-life endocrine and metabolic health.
Main Methods:
- Two rat models were used: premature weaning and dietary manipulation (small vs. large litters).
- Metabolic parameters including plasma cholesterol, thyroid function, and adrenal corticosterone were assessed in adulthood.
- Body composition and hormonal responses to stimuli were evaluated in adult rats.
Main Results:
- Premature weaning led to earlier spermiogenesis degeneration, elevated adult cholesterol, and altered thyroid radioiodine uptake and corticosterone production.
- Rats from small litters (indicating early nutritional restriction) exhibited higher adult plasma cholesterol, insulin, and body fat.
- Neonatal overfeeding or underfeeding affected diurnal corticosterone patterns and lipolysis/lipogenesis regulation.
Conclusions:
- Early neonatal interventions, including weaning timing and nutritional status, profoundly influence adult metabolic health in rats.
- These findings suggest that early life programming plays a significant role in the development of metabolic disorders.
- Further research into early life interventions is warranted to optimize long-term health and prevent disease.
Abstract:
Effects of early neonatal interventions on metabolic parameters later in life (s.c. late effects) were studied in rats using two models; namely, (a) the effects of premature weaning and (b) the effects of "dietary" manipulations during the suckling period (s.c. small vs. large litters). (a) Premature weaning of rats caused an earlier degeneration of spermiogenesis and elevated plasma cholesterol levels in adult animals when compared to levels found in animals weaned 12 days later (on day 30 after birth). In adult rats, radioiodine uptake in thyroid glands was lower in the group weaned prematurely. Premature weaning was followed by a decrease of corticosterone production in adrenal glands in adult animals; in female adult prematurely weaned rats, an elevated response of adrenal cortex to stressors was observed. Several other studies explored the "immediate" effects of early, premature weaning. (b) Early exposure to high fat diet evoked a hypercholesterolaemic response in adulthood following brief exposure to HF diet. Rats from litters reduced to 3 or 4 pups per mother on postnatal day 3 exhibited 2 days later plasma levels of cholesterol higher than in rats raised in large litters of 8 or 14. The difference between small and large litters was preserved for the whole lifespan of the animals. In adulthood, rats from small litters were fatter and had higher levels of plasma cholesterol and insulin. Other studies suggester that early dietary experience may regulate the pattern of drug metabolism in adult life. An inhibition of diurnal plasma corticosterone variation was found in rats overfed during the neonatal period and an increased stimulation of lipolysis by norepinephrine and lipogenesis by insulin was demonstrated in neonatally underfed rats. Interesting studies were reported in longitudinally studies in children: at the age of 9-12 year breast-fed children (for more than 6 months) had the highest cholesterol levels; on the other hand significantly increased levels of APO B, Apo A1, ATH index and Apo/B Apo A1 quotient (p < 0.05) were found in the nonbreast-fed group (27 references).
