Differentiating limb tissue affects neurite growth in spinal cord cultures.

Limb bud mesenchyme enhances and directs the growth of tadpole spinal cord nerve fibers in tissue culture. This effect on elongating neurites may involve alterations in nerve-substratum interactions by the presence of undifferentiated target tissues. The relationship between nerve fibers and their potential innervation sites can explain directed nerve growth to the developing limb.