Breathing-Related Brain Defect Found in Victims of Sudden Infant Death Syndrome

A brain defect that affects breathing has been found in babies who died of sudden infant death syndrome. The babies had lower levels of neurotransmitters--signaling chemicals--in the part of the brain that controls breathing, a team from Harvard Medical School reports in the December issue of the Journal of Neuropathology and Experimental Neurology.

The researchers studied the brains of 79 babies who died of SIDS. Compared to infants who died of other causes, the SIDS victims had 52% less kainate in the arcuate nucleus, a region of the brain that helps control breathing and blood pressure. The same team had earlier found that SIDS babies had less activity at a second point where neurotransmitters hook onto brain cells, known as the muscarinic cholinergic receptor. They said their findings suggested that as carbon dioxide levels rise and oxygen levels fall in the bloodstream during sleep, the brains of certain babies may not get the signal to alter their breathing or blood pressure to compensate.