Children of mothers whose diet during pregnancy was deficient in the essential nutrient choline have lower performance on cognitive tests. Cognition is rooted in the brain’s cortex, but a direct link between maternal dietary choline levels and cortical development in offspring had not been demonstrated. Experimental evidence of this link, and identification of a physiological mechanism, would greatly enhance our understanding of the importance of proper nutrition during pregnancy. Just-published research from Dr. Zeisel’s laboratory (Wang et al., 2016) shows that a maternal low-choline diet causes severe alterations of cortical growth and development in offspring and provides mechanistic insight into how this happens.
What they did
In this study, Zeisel’s group fed pregnant mice a diet with either normal or low levels of choline from post-fertilization days 11 through 17. Much of the mouse embryonic brain development occurs during this period. Wang et al. found that the offspring of mice fed the low choline diet had smaller brains and reduced thickness of the cortex. They then measured the number of neural progenitor cells in the cortex and found that the count was significantly reduced in offspring of low choline-fed mice (Figure 1). Neural progenitor cells give rise to most of the cells in the cortex, so a relative loss of these cells can have huge consequences for cortical development.
Wang et al. now show that a maternal diet low in choline during critical stages of embryonic brain development results in offspring with decreased brain size, fewer neurons, and altered cortical layering. The origins of these effects appear to be altered cell cycling, where low choline conditions decrease the proliferation of neural progenitor cells and increase early cell cycle exit. A connection between maternal choline intake level and offspring cognitive abilities has been known for several decades, but the physiological mechanisms were not determined. These new findings are important because they show that low maternal choline intake impairs normal growth and development of the cortex, the part of the mammalian brain most responsible for cognition, and because they identify involvement of a specific molecular signaling pathway. The results emphasize the importance of good maternal nutrition on children’s long-term health.
Wang, Y., Surzenko, N., Friday, W.B., & Zeisel, S.H. (in press). Maternal dietary intake of choline regulates development of the cerebral cortex in the offspring. FASEB J.