Tritiated leucine incorporation in the developing hamster facial nucleus with injury: An autoradiographic study

Tritiated leucine incorporation was examined after axotomy of the hamster facial nerve in development in an attempt to correlate structural maturation of the nucleolus with levels of competence in the metabolic response to axon section. Changes in neuronal tritiated leucine incorportation were characterized by autoradiographic examination of the facial neuronal population after axotomy as specific stages in nucleolar development. The ability to increase incorporation over the normal as a result of injury in development coincided with the time of final nucleolar maturation, between 20 and 24 days postnatal age. Thus, there was a correlation between a specific morphologic event, the appearance of the adult nucleolar configuration, and the appearance of the mature protein metabolic response to injury of increased leucine incorporation.