The effect of exclusive breastfeeding on synaptogenesis and cell survival in mouse offspring

The first thousand days of life are critical for determining a child's cognitive development in humans. Breastfeeding may provide the nutrients needed for brain development. Cognitive function has been widely associated with neuronal turnover, driven by synaptogenesis and apoptosis. To explore this hypothesis, this study aimed to examine the effect of exclusive breastfeeding (EBF) on cognitive function and neuronal turnover in the dentate gyrus of the mice hippocampus. We conducted cognitive function assessments using the Morris Water Maze (MWM) test. We also examined neuronal apoptosis with TUNEL assay and synaptogenesis using PSD-95 antibodies. The newborn mice (mixed gender) aged 0 days were randomly divided into two groups. The first group received exclusive breastfeeding (EBF, n = 14), while the second group (MF, n = 14) received mixed breast milk and formula milk. At postnatal day 21 (PND21), the MWM test was performed, followed by an assessment of neuronal apoptosis and synaptogenesis. In the MWM test, the escape latency of the EBF group was shorter than the MF group. There was a significant increase in PSD-95 expression and a decrease in TUNEL expression in the EBF group (p < 0.001) than in the MF group. In conclusion, exclusive breastfeeding is associated with higher cognitive function. Exclusive breastfeeding affects neuronal turnover by increasing synaptogenesis and decreasing apoptosis in the dentate gyrus of the hippocampus. This has both scientific and clinical implications, pointing to nutritional practices early in life that could optimise the attainment of cognitive potential.