Developmental abnormalities of medullary "respiratory centers" in sudden infant death syndrome

Dendritic development and gliosis in the medullary magnocellular reticular nucleus and solitary and dorsal vagal nuclei of 15 cases with sudden infant death syndrome (SIDS) and 23 control subjects were compared using morphometric Golgi and immunohistochemical methods. Developmental delay of the normal diminution of dendritic spines was found in the magnocellular reticular nucleus and/or vagal nuclei of 50 to 80% of SIDS infants. Astrocytes reactive with antisera to glial fibrillary acidic protein also increased in those regions, although dendritic spine density was inconsistent with the presence of astrogliosis in 20 to 40% of the cases. This delayed neuronal maturation of dendritic spines suggests there are immature neural respiratory control mechanisms in SIDS.