An enzyme found in the placenta is likely playing an important role in translating stress experienced by a mother early in pregnancy into a reprogramming of her developing baby's brain, research suggests. "People think that the placenta only serves to promote blood flow between a mom and her baby, but that's really not all it's doing," the lead investigator said. "It's a very dynamic endocrine tissue and it's sex-specific, and we've shown that tampering with it can dramatically affect a baby's developing brain."