Intraventricular hemorrhage is a common cause of morbidity and mortality in premature
infants. The rupture of the germinal zone into the ventricles entails loss of neural stem cells
and disturbs the normal cytoarchitecture of the region, compromising late
neurogliogenesis. Here we demonstrate that neural stem cells can be easily and robustly
isolated from the hemorrhagic cerebrospinal fluid obtained during therapeutic
neuroendoscopic lavage in preterm infants with severe intraventricular hemorrhage. Our
analyses demonstrate that these neural stem cells, although similar to human fetal cell
lines, display distinctive hallmarks related to their regional and developmental origin in the
germinal zone of the ventral forebrain, the ganglionic eminences that give rise to interneurons and oligodendrocytes. These cells can be expanded, cryopreserved, and differentiated in vitro and in vivo in the brain of nude mice and show no sign of tumoral
transformation 6 months after transplantation. This novel class of neural stem cells poses
no ethical concerns, as the fluid is usually discarded, and could be useful for the development of an autologous therapy for preterm infants, aiming to restore late neurogliogenesis
and attenuate neurocognitive deficits. Furthermore, these cells represent a valuable tool
for the study of the final stages of human brain development and germinal zone biology