Comparison of neural precursor cell fate in second trimester human brain and spinal cord

Neural transplantation holds promise for the treatment of traumatic brain a nd spinal cord injury by replacing lost cellular elements as well as repair ing neural damage. Fetal human stem cells derived from central nervous syst em (CNS) tissue are potential transplantable sources for all cell types fou nd in the mature human nervous system including neurons, astrocytes and oli godendroglia. Although nearly all areas of the fetal human neuraxis contain undifferentiated neural precursor cells, the phenotypic fate of the daught er cells might vary from one region to another during a specific developmen tal period. The purpose of this study was to compare the various cell types derived from neural precursors cultured from second trimester fetal human brain and spinal cord. To this end, brains (n = 8) and spinal cords (n = 8) of 15-24 week fetuses were dissociated and grown in culture medium supplem ented with epidermal growth factor (EGF) basic fibroblast growth factor (FG F) and leukemia inhibitory factor (LIF). The proliferating precursor cells from both brain and spinal cord grew as spherical masses that were plated o n laminin-coated dishes after seven days in culture. During the next 5-7 da ys, the cells that emerged from these spheres were fixed and processed for immunocytochemistry. Brain derived spheres gave rise to cells expressing an tigens specific for neurons (MAP-2ab and neuron specific-intermediate filam ents), astrocytes (GFAP) and oligodendrocytes (A007). in contrast, cells th at emerged from spinal cord derived spheres were only immunoreactive for GF AP. These data suggest that neuroepithelial precursor cells from different CNS regions, although similar in their responsiveness to proliferative grow th factors, might differ in their ability to generate different cell types in the adult CNS.