Dietary blueberry supplementation affects growth but not vascularization of neural transplants

Transplantation of neural tissue has been attempted as a treatment method for neurodegenerative disorders. Grafted neurons survive to a lesser extent into middle-aged or aged hosts, and survival rates of <10% of grafted neurons is common. Antioxidant diets, such as blueberry, can exert powerful effects on developing neurons and blood vessels in vitro, but studies are lacking that examine the effects of these diets on transplanted tissues. In this study, we examined the effects of a blueberry diet on survival, growth, and vascularization of fetal hippocampal tissue to the anterior chamber of the eye of young or middle-aged female rats. Previous work from our group showed significant increase in neuronal survival and development with blueberry diet in grafts. However, the effects of antioxidant diet on vascular development in grafts have not been explored previously. The age of the host affected individual vessel morphology in that aged hosts contained grafts with thick, undeveloped walls, and wider lumen. The blood-brain barrier also appeared to be affected by the age of the host. The blueberry diet did not affect vessel morphology or density of vessel-associated protein markers but gave rise to significantly increased growth capacity, cytoarchitecture, and the final size of hippocampal grafts.