The Sudden Infant Death Syndrome which affects babies under a year could be caused by a brain anomaly – the serotonin deficit.  Serotonin, a monoamine neurotransmitter, is primarily found in the central nervous systems and in the gastrointestinal tract.

The researchers at Children’s Hospital Boston discovered that babies who died in their sleep had few serotonin receptors in their blood. The anomalies were discovered in the lower part of the brain, in the rachidian bulb.

Serotonin and the way it’s processed in the brain helps coordinate breathing, carbon dioxide sensibility, temperature sensibility, cardiac rhythm and arterial pressure. Babies who suffer from these anomalies could die in their sleep because these functions can’t be controlled by the nervous system.

If a baby sleeps face down or has their face covered by bedding, they are thought to re-breathe exhaled carbon dioxide, therefore they are breathing in less oxygen. Normally, this rise in carbon dioxide activates nerve cells in the brainstem, which in turn stimulate respiratory and arousal centres in the brain so that the baby does not asphyxiate.

To avoid SIDS doctors recommend sleeping the baby face up, avoid sleeping two babies in the same bad and also to quit smoking during pregnancy or around the baby. However to better explain what causes the abnormalities and how they can be prevented more research is needed.