OBJECTIVETo study the effect of hyperbaric oxygenation (HBO) on the differentiation of the implanted human neural stem cells (hNSCs) into neurons in neonatal rats following hypoxic-ischemic brain damage (HIBD).

METHODSHIBD model was prepared by ligation of the left common carotid artery, followed by 8% hypoxia exposure in 7-day-old Sprague-Dawley rat pups. Three days later, the rats received implantation of hNSCs into the left cerebral ventricles. Then the survived rats were randomly divided into two groups: transplantation alone and transplantation+HBO (n=8 each). HBO treatment was administered (1.8 ATA, 1 hr once daily for 10 days) in the transplantation+HBO group 1 hr after hNSCs transplantation. Brains were removed 10 days after transplantation. Frozen coronal sections were prepared for immunofluorescence analysis to detect the neural differentiation of the transplanted cells in the cerebral cortex and hippocampus.

RESULTSDifferentiated neurons of implanted cells distributed mainly in the cortex and the hippocampus of the injured side. There was no difference in the number of neurons in the cortex between the two groups, while the number of neurons in the hippocampus significantly increased in the transplantation+HBO group compared with that in the transplantation alone group (231.4+15.1 vs 162.6+5.6; P<0.05).

CONCLUSIONSHBO treatment may promote the differentiation of implanted hNSCs into neurons in the hippocampus of neonatal rats following HIBD.