Effect of veratridine on the release of neurotrophic factors in nerve tissue cultures.

The depolarizing agent veratridine was shown to affect the level of neurotrophic substances in combined cultures of neonatal rat hippocampus and chick embryo spinal ganglia. In this experimental model, the level of neurotrophic factors in rat hippocampus explants increased as a result of increases in neuronal activity mediated by veratridine. The effects of these neurotrophins on neurite growth in the sensitive spinal ganglion neurons in the combined cultures were evaluated using morphometric methods. Neurite-stimulating effects were seen when veratridine was added to the nutritive medium at a concentration of 90 nM. Antibody to nerve growth factor blocked the action of veratridine. These results demonstrate a role for neuron activity as a regulatory mechanism controlling the expression of neurotrophins.