Can what a mother eats affect her baby? Claudia Buss of the Charité – Universitätsmedizin Berlin and the University of California, Irvine and her colleagues conducted a longitudinal study of mothers and their newborn babies, and discovered that increased production of the cytokine interleukin-6 (IL-6) in mothers can lead to alterations in the brain connectivity of her offspring.
Buss and coworkers took blood samples of pregnant women and measured levels of the cytokine IL-6 early in pregnancy, during the middle of the pregnancy, and near the end of their pregnancy. Shortly after the birth of their babies, Buss and others conducted MRI scans of the newborns. “This is the only way that we will be able to understand prenatal influences that are not confounded by post-natal influences,” Buss said at a November 17th press conference at the Society for Neuroscience (SfN) annual meeting in Washington, DC. In particular, Buss and her team looked for patterns of synchronized activity in the default mode network (DMN). The DMN is a network of brain regions that are active when the individual is not focused on the outside world and the brain is awake, but at rest. During goal-oriented activity, the DMN is deactivated and another network called the task-positive network (TPN) is activated. The DMN may correspond to task-independent introspection, or self-referential thought, while the TPN corresponds to action. Dysfunction of the DMN has been linked to psychiatric disorders.
The group found that the infant DMN “doesn’t look like adult network, but it’s emerging,” Buss said. “It’s there in an immature state.” More importantly, higher maternal gestational IL-6 concentration predicted reduced DFM connectivity. The infant brain was “less strongly connected under conditions of high maternal IL-6 concentrations,” Buss said.
In another study by neuroscientists at Duke University showed that the maternal diet of mice can cause inflammatory and behavior changes in offspring. Staci Bilbo of Duke University and her team found that a high-fat diet in the mother can lead to inflammation in the body’s fat tissue as well as immune changes in brain that may be linked to psychiatric disorders like anxiety and depression. The researchers fed mice either a low-fat diet or a high-fat diet, either enriched or not enriched for branched chain amino acids (BCAAs). Bilbo’s group examined the mothers’ brains midway through pregnancy and found increased expression of inflammatory cytokines in the hypothalamuses of mice fed a high-fat diet. These changes were also accompanied by postpartum increases in depressive-like behaviors in mice fed a BCAA-enriched diet and an increase in anxiety-like behaviors in mice fed a high-fat diet.
According to Bilbro, the offspring of these mothers showed “striking” differences in the expression of inflammatory cell types and in the behavior of the newborn pups. Infants born to moms fed a high-fat diet showed decreased expression of microglia markers and increased anxiety-like behaviors. However, mice born to moms on a high-fat, high-BCAA diet showed increased expression of a marker for astrocytes.
“Maternal diet does matter,” said Bilbo. “We believe [these changes] may be contributing to both metabolic changes as well as mood changes” in the moms and their offspring.