Do white cells matter in white matter damage?

Support is provided for the hypothesis that activated leukocytes, especiall y monocytes/macrophages, contribute to cerebral white matter damage in extr emely low gestational age newborns. Much of the evidence is indirect and co mes from analogies to brain diseases in adults, and from models of brain da mage in adult and newborn animals. If the recruitment of circulating cells to the brain contributes to white matter damage in extremely low gestationa l age newborns, then minimizing the transendothelial migration of circulati ng cells by pharmacological manipulation might prevent or reduce the occurr ence of neonatal white matter damage and the disabilities that follow.