Wheat germ agglutinin inhibits nerve fiber growth and concanavalin A stimulates nerve fiber initiation in cultures of dorsal root ganglia neurons.

Treatment of dorsal root ganglion (DRG) neurons with the lectin wheat germ agglutinin (WGA; 25 micrograms/ml), which binds to N-acetylglucosamine containing glycoconjugates, inhibits nerve fiber growth in culture. DRG neurons treated with WGA have significantly reduced total output in nerve fiber length per neuron as well as reductions in the average length of the individual nerve fibers extended. The inhibition of nerve fiber growth by WGA is concentration-dependent, specific, reversible and not mimicked by treatment with several metabolic poisons. In contrast, treatment with the lectin concanavalin A (25 micrograms/ml), which binds to mannose-containing glycoconjugates, increases the number of nerve fibers produced per neuron. These results suggest that lectins which bind to distinct carbohydrate moieties can differentially regulate nerve fiber growth.