Serotonin may be at the root of Sudden Infant Death Syndrome (SIDS)

Reporting in the July 4 issue ofScience, Italian researchers explain how alterations in normal serotonin levels in a mouse model resulted in sudden death for many of the mice. And, just prior to death, the mice experienced changes in their heart rate and their temperature that were similar to the changes suspected to occur in SIDS.

"This mouse model is important. Causing dysfunction in brainstem serotonin can lead to death in a majority of affected animals," Marian Willinger, a SIDS expert with the U.S. National Institute of Child Health and Human Development, said at a press conference Thursday. She added that the severe cardiac and thermal regulation changes that occurred in the mice are similar to risk factors associated with SIDS. For example, she said, stomach sleeping is more likely to cause heart rate variability than back sleeping. Over-bundling babies, and thus overheating them, is also a known risk factor for SIDS, she said.