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Updated: Jun 6, 2026
Neurodevelopmental Reflex Testing in Neonatal Rat Pups
Published on: April 24, 2017
Pre- and/or postnatal protein restriction in rats impairs learning and motivation in male offspring
L A Reyes-Castro1, J S Rodriguez, G L Rodríguez-González
1Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, 14000, Mexico.
Insights
Maternal low protein diets during pregnancy and lactation impair offspring
Area of Science:
- Neuroscience
- Developmental Biology
- Nutritional Science
Background:
- Suboptimal developmental environments can lead to lifelong health issues.
- The impact of intrauterine conditions on offspring learning and motivation is not well understood.
Purpose of the Study:
- To investigate the effects of maternal low protein diet during gestation and lactation on offspring associative learning and motivation.
- To determine if prenatal or postnatal nutritional challenges have differential impacts on behavioral development.
Main Methods:
- Mothers were fed either a control (20% casein) or low protein (10% casein) diet during pregnancy and/or lactation.
- Offspring behavior was assessed using operant conditioning (fixed ratio tasks) and a progressive ratio task to measure learning and motivation.
- Four experimental groups were established: CC (control pregnancy, control lactation), RR (restricted pregnancy, restricted lactation), CR (control pregnancy, restricted lactation), and RC (restricted pregnancy, control lactation).
Main Results:
- Offspring exposed to low protein diets showed impaired learning in fixed ratio-1 and fixed ratio-5 operant conditioning tasks.
- Maternal low protein diet during pregnancy and lactation significantly reduced offspring motivation and response for positive reinforcement.
- Prenatal nutritional restriction (RC group) particularly impaired associative learning, while both prenatal and postnatal restrictions affected motivation.
Conclusions:
- Perinatal exposure to an isocaloric low protein diet negatively programs offspring, leading to deficits in learning and motivation.
- The prenatal period appears to be a more vulnerable window for nutritional challenges impacting offspring behavioral development.
- These findings highlight the critical role of maternal nutrition during development for long-term offspring health and behavior.
Abstract:
Suboptimal developmental environments program offspring to lifelong health complications including affective and cognitive disorders. Little is known about the effects of suboptimal intra-uterine environments on associative learning and motivational behavior. We hypothesized that maternal isocaloric low protein diet during pregnancy and lactation would impair offspring associative learning and motivation as measured by operant conditioning and the progressive ratio task, respectively. Control mothers were fed 20% casein (C) and restricted mothers (R) 10% casein to provide four groups: CC, RR, CR, and RC (first letter pregnancy diet and second letter lactation diet), to evaluate effects of maternal diet on male offspring behavior. Impaired learning was observed during fixed ratio-1 operant conditioning in RC offspring that required more sessions to learn vs. the CC offspring (9.4±0.8 and 3.8±0.3 sessions, respectively, p<0.05). Performance in fixed ratio-5 conditioning showed the RR (5.4±1.1), CR (4.0±0.8), and RC (5.0±0.8) offspring required more sessions to reach performance criterion than CC offspring (2.5±0.5, p<0.05). Furthermore, motivational effects during the progressive ratio test revealed less responding in the RR (48.1±17), CR (74.7±8.4), and RC (65.9±11.2) for positive reinforcement vs. the CC offspring (131.5±7.5, p<0.05). These findings demonstrate negative developmental programming effects due to perinatal isocaloric low protein diet on learning and motivation behavior with the nutritional challenge in the prenatal period showing more vulnerability in offspring behavior.
