Study sees serotonin-SIDS link

Mice genetically engineered to overproduce the brain chemical serotonin died at an early age after developing symptoms similar to sudden infant death syndrome, suggesting improper regulation of serotonin might play a role in SIDS in humans.

The majority of the mice died after being unable to regulate their heart rate and body temperature, scientists reported Friday in the journal Science.

Dr. Cornelius Gross, a study author and head of the project at the European Molecular Biology Laboratory in Monterotondo, Italy, said that the work could prompt clinical research “to devise diagnostic tests to try to identify those kids most likely to … die of SIDS.”

SIDS is a condition in which seemingly healthy babies between 1 month and 1 year old die without warning or explanation. It kills approximately 2,700 infants in the U.S. each year.

The mice were part of a study on serotonin’s role in aggression and anxiety, but after they began dying a fellow scientist suggested that it might be related to SIDS.

“This was a chance discovery,” Gross said.

Serotonin, in addition to affecting mood, regulates bodily functions such as temperature, respiration and heart rate.

Their findings support autopsy-based results reported from 2006 in which researchers from Children’s Hospital Boston led by Dr. Hannah Kinney found that infants who died of SIDS had abnormal serotonin-producing cells in their brain stems.