Dorsal root ganglia and nerve growth factor: a model for understanding the mechanism of GM1 effects on neuronal repair.

The experimental strategy of adding monosialoganglioside GM1 to a culture medium of fetal chick dorsal root ganglia (DRG) was utilized as a model system in which to examine the potential role of GM1 in modulation of neuronal cell responsiveness to nerve growth factor (NGF). Data indicate that the addition of GM1 to DRG explants or to DRG dissociated neuronal cells in culture enhances NGF-induced neurite outgrowth, neurite complexity, and neuronal cell survival following NGF withdrawal. The GM1 molecule apparently facilitates the acquisition or maintenance of the NGF-induced specific neuronal properties. Results are consistent with the hypothesis that the presence of GM1 molecules on the neuronal cell surface, either endogenous or following stable insertion of exogenous molecules, plays a prominent role in the modulation of functional neuronal cell behavior in response to varying neuronotrophic signals. This may prove to be relevant for the comprehension of GM1 effects on the facilitation of central nervous system repair processes.