"We found that the babies who died of SIDS had abnormalities in serotonin in regions of the brain stem that control breathing and heart rate and blood pressure during sleep."

VOA: standard.2010.02.08

Further down this line here are embryonic or let's say adult brain stem cells.

沿着这条线再往后一些就是胚胎,或者就说是成人脑中的干细胞吧

耶鲁公开课 - 生物医学工程探索课程节选

Stem cells have the ability to grow other cells, such as heart, nerve or brain cells.

VOA: special.2010.06.15

Researchers say the speech impediment appears to stem from a defectin the gene that regulates the way brain cells break down and recycle waste products.

VOA: standard.2010.02.11