A method for long-term culture of murine dorsal root ganglia neurons was developed which provided cultures containing 80% neurons. The Cells exhibited formaldehyde induced catecholamine fluorescence. DRG neurons incorporated {('3)H}-N-acetyl-mannosamine into GT1b-GD1b, GD2-GD1a, GM1 and GM2 with GM2 containing the greatest amount of label. The major ganglioside species of adult murine DRG was GD1a, with lesser amounts of TT1b, GD1b, GT1a, GD2 and GM1. GD1a content of adult DRG was similar to that of adult cerebrum. Fiber tracts of the CNS and PNS appeared to have similar ganglioside components which included a diverse monosialoganglioside population. The PNS areas examined had lower relative concentrations of polysialylated gangliosides and lower total sialic acid than did CNS regions. This suggests that certain gangliosides were associated with defined regions of the murine nervous system. Murine S20Y neuroblastoma cells express some of the differentiated properties of neurons in the postconfluent state. The number of argyrophilic processes and AChE and CAT activities increased from the pre- to the postconfluent state. Membrane-associated sialic acid content decreased with increasing cell density. {('125)I}-WGA binding by S20Y cells increased (TURN)40% with increasing cell density, while {('125)I}-Con A binding showed no significant change. WGA bound glycoproteins from KCl extracts of plasma membranes from either postconfluent or preconfluent S20Y cells were identified by their mobility on SDS-PAGE. Higher molecular weight WGA bound glycoconjugates were present in the postconfluent extracts. The observed density dependent changes may be indicative of those which normally occur as neurons differentiate. The effect(s) of the addition of specific gangliosides to S20Y cells was examined. GD1a induced the most profound reduction in proliferative capacity while GM1 induced expression of microvilli on the cell surface as visualized by scanning electron microscopy. These specific ganglioside effects correlate to some degree with the morphological changes observe in neural development in vivo which occur coincidentally with increases in GM1 and GD1a content.
