Region-specific changes in Mus musculus brain size and cell composition under chronic nutrient restriction

Area of Science:

• Neuroscience
• Developmental Biology
• Nutritional Science

Background:

• Nutrition is a critical environmental factor influencing tissue and organ development.
• Nutrient restriction during development may lead to differential resource allocation, potentially sparing brain growth.
• The extent and regional specificity of this brain-sparing effect remain unclear.

Purpose of the Study:

• To investigate the impact of maternal nutrient restriction on brain development in offspring.
• To analyze morphological changes and cell composition across different brain regions.
• To determine if brain sparing occurs uniformly or is region-specific.

Main Methods:

• Maternal exposure to nutrient restriction during pregnancy and lactation in mice.
• High-resolution magnetic resonance imaging (MRI) for morphological analysis.
• Isotropic fractionator method for cell composition analysis.
• Diffusion tensor imaging (DTI) for white matter organization assessment.

Main Results:

• Brain regions exhibited differential sensitivity to maternal protein restriction, showing distinct patterns of volume reduction.
• The cerebellum showed significant reductions in absolute and relative volume.
• Cerebral cortex volume was relatively preserved, indicating region-specific sparing.
• Alterations in cell composition and white matter organization were also region-specific.
• Observed changes were not directly correlated with regional metabolic rates or growth trajectories.

Conclusions:

• Maternal nutrient restriction leads to region-specific alterations in offspring brain development.
• The cerebellum is particularly vulnerable, while the cortex shows relative preservation.
• These findings highlight the microstructural and macrostructural mechanisms underlying regional brain sparing in response to undernutrition.