Abstract
BACKGROUND/AIM: Neurogenesis is a complex process to generate new neurons from neural progenitor cells. Neural progenitor cells are observed in two principal neurogenic regions of the forebrain, the subventricular zone and the subgranular zone of the hippocampal dentate gyrus. The cerebral cortex also plays a role as the neurogenic zone under hypoxic conditions. Hypoxia has many effects on neurogenesis, but the effect of chronic prenatal hypoxia on paired box 6 (Pax6), a protein that plays an important role in neurogenesis, has not been studied in vivo. In the present study, we used a rat model to evaluate the effect of hypoxia on Pax6 immunoreactivity. MATERIALS AND METHODS: Hypoxia status was induced by unilateral uterine-artery ligation in pregnant rats. The fetuses were obtained from the uterine horn on the twenty-first day of pregnancy and immunohistochemistry of the fetal brain was examined regarding anti-hypoxia-induced factor 1α and Pax6 antibody. RESULTS: The density of HIF1α-IR cells in the hypoxia group was greater than the density of HIF1α-IR cells in the control group in the subventricular zone, subgranular zone, and cerebral cortex. The density of Pax6-IR cells in the hypoxic group was higher in both the subventricular zone and the subgranular zone than in the control group. However, the density of Pax6-IR cells in the cerebral cortex was lower in fetuses that experienced hypoxia than in control fetuses. CONCLUSION: These results suggest that Pax6 immunoreactivity showed diverse patterns in the neurogenic zone after prenatal hypoxia and Pax6 has important effects on neurogenesis.