The Role of the Svz Neurovascular Niche in Recovery from Neurodevelopmental Handicaps Associated with Preterm Birth

In the course of one year in the United States approximately 80000 individuals will suffer strokes, over 10000 will have spinal cord injuries, over 200000 will experience traumatic brain injury and of the 60000 very low birth weight preterm infants born, 5000 will test in the mentally retarded range. The impacts of these injuries to the patients, their families, the health care system and society are devastating. While survival from these injuries has improved over the years, treatments affecting recovery are still limited. Following all these injuries the repair/recovery process is thought to involve both angiogenesis and neurogenesis. During development and throughout our lifetime neuronal death, maintenance and neurogenesis occur in a tightly controlled fashion (1-4). The neurogenic zones, replete with neural stem cells (NSC) are found in the subventricular zones, located along the lateral aspects of the lateral ventricles and the subgranular zones (SGZ), located in the dentate gyrus of the hippocampus. These neurogenic zones are intimately associated with their local microvasculature beds (EC). Further, the behaviors of the neuronal stem cells and microvasculature in these zones are thought to be reciprocally co-regulated, in part, via oxygen tension, local NSC and EC soluble and solid phase factors including neurotrophins, vascular growth factors, cytokines and nitric oxide (5-9). Following injury, NSC, supported by their local vasculature, are thought to proliferate, migrate to and differentiate at injury sites, affecting variable degrees of structural and functional recovery (10). Unfortunately, in many instances recovery from injury is incomplete. THE ROLE OF THE SVZ NEUROVASCULAR NICHE IN RECOVERY FROM NEURODEVELOPMENTAL HANDICAPS ASSOCIATED WITH PRETERM BIRTH