Target-dependent survival of tadpole spinal cord neurites in tissue culture.

Survival of nerve fibers growing from frog tadpole spinal cord explants in tissue culture was examined as a function of the absence or presence of target limb tissue. Neuritic outgrowth was maintained in serum-free medium for significantly longer times when cord was co-cultured with young limb tissue or limb conditioned medium than when grown alone. The results are suggested to be relevant to possible mechanisms controlling the loss of neurons from the spinal motor centers during in vivo development.