MRI detection of the migrating neuronal precursors in normal and hypoxic-ischemic neonatal rat brain by in vivo cell label with MPIO

Abstract

In this study,10-day-old normal rats (n=6) and hypoxic-ischemic (H-I) neonatal rats (n=6) were injected with the micronsized iron oxide particles (MPIOs) into the anterior lateral ventricle. 2D and 3D gradient echo MRI was performed with a 7T animal scanner in hour 3, day 3, day 7 and day 14 after the MPIOs injection. Then animals were sacrificed for double staining with iron and mature neurons. In normal neonatal rat brain, the migrating pathway of the endogenous neural progenitor cells (NPCs) with MPIO is mainly along the rostral migratory stream to the olfactory bulb. In H-I neonatal rat brain, the migration of endogenous NPCs with MPIO is mainly toward injured boundary. MRI can facilely detect the above migrations in 2 weeks. Therefore, in vivo magnetic cell labeling of endogenous NPCs with MPIO and subsequently non-invasive, serial MRI monitoring should open up a new approach to probe into the mechanism of cell migration in the developmental brain under physiological and pathologic states.