Biological importance of the retrograde axonal transport of nerve growth factor in sensory neurons.

Nerve growth factor is retrogradely transported in sympathetic and sensory neurons throughout life. Although this transport is known to be biologically significant in sympathetic neurons, such a function was not yet known in sensory ganglia. By using the neuropeptide substance P as a biochemical marker, we show that sensory ganglia from newborn and adult rats respond in nerve growth factor and that its retrograde axonal transport is biologically relevant, as indicated by an increase in substance P and in general protein content.