A study by Yale physicians suggests that sudden infant death syndrome (SIDS) may be linked to a defect in a neuron that alerts the body to high carbon dioxide levels.
“When someone falls asleep with their face in a pillow, carbon dioxide levels rise,” said George B. Richerson, M.D., Ph.D., HS ’91, associate professor of neurology and physiology. “The normal response is to wake up slightly, turn the head and breathe harder. There is evidence that some infants who die of SIDS lack this normal protective response.”
SIDS strikes one in 1,000 infants and is the leading cause of death of children between two weeks and one year of age. Physicians have identified risk factors including lying face down, prematurity, low birth weight and a recent, mild upper-respiratory infection. Previous studies had found abnormalities in serotonin-containing neurons in the brains of infants who died of SIDS. Richerson and his co-investigators reported in Nature Neuroscience that, in rats, serotonergic neurons are situated next to large arteries in the brain, an ideal location for sensing carbon dioxide levels in arterial blood.