New method of purification for establishing primary cultures of ensheathing cells from the adult olfactory bulb.

Ensheathing cells exclusively enfold olfactory axons. The ability of olfactory axons to reinnervate the adult mammalian olfactory bulb throughout the lifetime of an organism is believed to result from the presence of this unique glial cell in the olfactory system. This theory has been substantiated by research demonstrating the ability of transplanted ensheathing cells to promote axonal regrowth in areas of the central nervous system that are normally nonpermissive. A simple method for purifying ensheathing cells resulting in a large yield of cells is therefore invaluable for transplantation studies. We have developed such a method based on the differing rates of attachment of the various harvested cell types. The greatest percentage of cells (70.4%) that attached during the first step of the separation was determined to be fibroblasts. The remainder of the cells were classified as astrocytes (20.8%) and ensheathing cells (6.8%). The percentage of attached astrocytes (67.6%) was greatly increased during the second purification step while the percentage of fibroblasts decreased greatly (27.9%) and the percentage of ensheathing cells (5.3%) slightly decreased. In the final cultures, 93.2 % of the attached cells were ensheathing cells, while astrocytes (5.9%) and fibroblasts (1.4%) were only minor components. This simple, inexpensive method of purifying ensheathing cells will facilitate their use in central nervous system regeneration research.