Scientists have come closer to explaining the cause of SIDS, the devastating syndrome that takes the lives of seemingly healthy babies without warning.

The study is published in the Journal of the American Medical Association.

In an examination of several dozen SIDS cases, Dr. David Paterson and colleagues identified abnormalities in the part of the brain that governs breathing, heart rate, blood pressure, arousal and head turning.

The infants who fell victim to crib death may have suffocated due to their brain's inability to react to abnormally high levels of carbon dioxide or dangerously low levels of oxygen, the researchers speculated.

The difficulty seems to center on the chemical serotonin and the brain's ability to use and reuse it. In addition to being a mood regulator, seratonin is involved in the regulation of breathing.