For several years, scientists in the lab of Tamas Horvath, D.V.M., Ph.D., have studied UCP2, a protein that facilitates the metabolism of fatty acids. Breast milk is rich in fatty acids, and UCP2 helps neurons in the brains of newborn animals utilize these nutrients.
Horvath and colleagues in Spain and Brazil have now discovered that UCP2 levels are significantly lower in mice delivered by Caesarean section than those born vaginally, a difference that may persist into adulthood. As reported August 8 in PLoS One, mice with impaired UCP2 function have smaller nerve cells in the hippocampus, a brain region involved in memory, and these cells make far fewer connections with other neurons. Moreover, mice with low UCP2 levels perform differently on behavioral and memory tests.
Because UCP2 gene expression is induced by cellular stress, the authors suggest that reduced oxygen levels and restricted blood flow experienced by animals during vaginal birth may trigger production of the protein.
“The increasing prevalence of C-sections driven by convenience rather than medical necessity may have a previously unsuspected lasting effect on brain development and function in humans as well,” says Horvath, the Jean and David W. Wallace Professor of Biomedical Research and chair of the Department of Comparative Medicine.