CONCURRENT ISOLATION AND CHARACTERIZATION OF OLIGODENDROCYTES, MICROGLIA AND ASTROCYTES FROM ADULT HUMAN SPINAL-CORD

A cellular preparation of highly enriched oligodendrocytes was obtaine d from adult human spinal cord by Percoll gradient centrifugation foll owed by either differential adhesion or fluorescence-activated cell so rting after immunostaining with an antibody against galactocerebroside (O1). The adherent and O1-negative cell fractions were >96% microglia . The non-adherent and O1-positive fractions were >96% positive for th e oligodendrocyte markers O4 and O1, 0-2% positive for glial fibrillar y acidic protein, and were devoid of neuronal or microglial markers. I f the oligodendrocyte fraction was co-cultured with purified dissociat ed rat dorsal root ganglion neurons, the oligodendrocytes adhered to t he axons and their numbers increased over a 4 week period. However, my elin sheaths were not produced around axons in these cultures. In cont rast. if the oligodendrocyte cell fraction was grown alone in culture for >3 weeks, the number of oligodendrocytes decreased and a layer of astrocytes developed underneath the oligodendrocytes. The oligodendroc ytes could be eliminated from these cultures by subsequent passaging, thus producing cultures of pure astrocytes. The astrocytes accumulated both K+ and glutamate with kinetic properties similar to those report ed for rodent astrocytes. We suggest that these astrocytes arose in pa rt from an O4/O1-positive precursor which did not initially express gl ial fibrillary acidic protein. These results define a relatively simpl e method by which highly enriched populations of oligodendrocytes, ast rocytes and microglia can be obtained from adult human spinal cord,