Brain Stem Changes Linked to Sudden Infant Death
Serotonin responsive neurons, receptors altered in medulla of SIDS victims
TUESDAY, Oct. 31 (HealthDay News) -- Abnormalities in a region of the brain stem containing serotonergic neurons and critical for respiratory drive may play an important role in sudden infant death syndrome (SIDS), according to a report in the Nov. 1 issue of the Journal of the American Medical Association.
David Paterson, Ph.D., from Harvard Medical School in Boston, and colleagues used autopsy tissue to measure the number and density of serotonergic neurons and serotonin receptors in the brain stem of infants who died from SIDS. Depending on the assay, 16 to 31 SIDS cases were used and compared to six to 10 controls.
SIDS cases had significantly higher serotonergic neuron counts and density, but lower numbers of serotonin receptor binding sites in the medulla compared with control cases. Male SIDS cases had significantly lower serotonin receptor binding sites in the raphe obscurus compared with females, perhaps identifying a reason for the higher prevalence of SIDS in boys.
"Recognizing that 5-HT influences a broad range of physiological systems including the regulation of breathing, the cardiovascular system, temperature and the sleep-wake cycle, the study by Paterson et al extends the available literature in support of the underlying hypothesis that SIDS is the result of 5-HT-mediated dysregulation of the autonomic nervous system," writes Debra Ellyn Weese-Mayer, M.D., of Rush University Medical Center in Chicago, in an accompanying editorial.