[In vivo labeling of rat neural progenitor cells in subventricular zone with superparamagnetic iron oxide for tracking of magnetic resonance imaging].

Objective: To explore the feasibility of in vivo labeling of adult rat neural progenitor cells (NPCs) in subventricular zone (SVZ) with superparamagnetic iron oxide particles (SPIOs) for tracking of magnetic resonance imaging (MRI).

Methods: A total of 7 SD rats were stereotactically injected with 3 µl SPIOs (7 mg Fe/ml) into anterior horn of right lateral ventricle and then 5-bromo-2'-deoxyuridine (BrdU) was injected intraperitoneally once daily for 1 week. MRI was performed at 1, 3, 7 and 14 days post-injection. After the final MRI scan, all rats were transcardially perfused and their brains removed and fixed. The sections were processed for Prussian blue iron staining and Prussian blue plus BrdU immunohistochemical staining.

Results: In all experimental animals, SPIOs were predominantly located in the anterior horn of right lateral ventricle and partial SPIOs entered the ventricular system. A needle path and a distribution of SPIOs along rostral migratory stream (RMS) towards olfactory bulb (OB) were depicted at the sagittal view of T2(*)WI, moderate MR artifact was visible and SPIOs tracking NPCs were successful (success rate of 100%). The result of staining showed SPIOs labeling NPCs were effective. And the labeling rates were 75.5%, 42.3%, 23.6% in SVZ, RMS and OB respectively.

Conclusion: Effective in vivo labeling of adult rat NPCs in SVZ with SPIOs is feasible. And dynamical migration of labeling NPCs along RMS towards OB may be visualized on MRI.