An Experimental Study On Survival And Differentiation Of The Transplanted Neural Stem Cell In Ventral Horn Of Spinal Cord After Brachial Plexus Avulsion,and The Protection To The Injured Motoneurons

[Objective]: To study the survival, migration and differentiation of the transplantedneural stem cells, the protection on ventral horn motoneurons, and thenitricoxidesynthase (NOS) expression change after brachial plexus avulsion.[Methods]: Neural stem cells from spinal cord of neonatal rats were isolated,cultured, expanded, and labeled by BrdU before transplantation. 60 adult healthy SDrats were randomly divided into three groups after brachial plexus avulsion (RootsC_5-7): one group was transplanted with living neural stem cells into C₆ ventral hornright after root avulsion, and a second group transplanted with dead stem cells, whilethe third one received no transplantation. In 1, 2, 4, 8, 12 weeks after injury, animalswere perfused and spinal cords were dissected out for histology andimmunohistochemistry assay.[Results]: After transplanted into ventral horn of spinal cord, the neural stem cellscould survive, migrate for at least one segment of spinal cord and differentiate intoneurons and astrocytes. The number of motoneurons in the ventral horn decreasedmarkedly after brachial plexus avulsion. The survival rate of motoneurons in livingneuronal stem cell transplantation group was higher than in the other two groups 2, 4,8, 12 weeks after injury along with a decreased nitricoxidesynthase expression.[Conclusion]: After being transplanted into the ventral horn of spinal cord in the ratssuffered from brachial plexus avulsion, The neural stem cells survived, migrated anddifferentiated, and the stem cells engraft markedly reduced the secondary ventral hornmotoneurons death by decreasing the nitricoxidesynthase expression.