Primary retinal and cortical glial cell cultures: effects of medium and serum on attachment and growth

Glial cells of the retina are anatomically distinctive and are thought to contribute importantly to retinal electrophysiology. However, no adequate preparation exists for studying them in isolation, in vitro. This report provides guidelines for primary retinal glial cultures (RET) and compares basal tissue culture features with those for neocortical glia (CX) and the well-studied rat glial line, C6. Cell attachment and growth of RET, CX, and C6 are unique. These differences are explored by the use of specific media and sera. RET attachment, unlike that for CX or C6, was far more sensitive to medium than serum. RET cells attached least quickly, CX most quickly; 4 hr after plating 20% of RET remained unattached. RET growth was poor and relatively insensitive to medium. In contrast, growth of CX or C6 was medium dependent. Serum had substantial effects on the growth of all three glial lines. Pig, goat, horse, and dog sera were particularly effective, often comparing favorably to fetal calf serum. Medium or serum optimal for cell attachment, typically, was not optimal for growth and serum effects were more dramatic than those of medium. By all measures, CX and C6, both derived from brain, were more alike than were the two rabbit primaries, CX and RET. The data reveal substantial differences between presumably similar cells and indicate a need for an empirically based choice of both basal-salt media and serum to optimize specific aspects of cell development in culture.