The fate of newly synthesized proteins in nerve and glial cells following nerve injury as shown by electron microscope radioautography.

Following peripheral crush of hypoglossal nerve the fate of newly synthesizing proteins in corresponding nerve and glial cells was traced out using light and high resolution radioautography after intraventricular injection of 3H-leucine. Radioautographic analysis was applied on the normal and chromatolytic neurons and their glial surroundings 45 min after injection of labelled precursor. Both chromatolytic neurons and surrounding glia showed higher incorporation of labelled proteins than those of control nerve and glial cells. Relative specific radioactivity (RSR) of ergastoplasm and lysosomes were increased in the chromatolytic neurons, whereas RSR of nuclei, mitochondria and Golgi apparatus were decreased. Contrary to neurons, RSR of corresponding compartments in experimental glial cells except lysosomes showed reciprocal values in comparison with control glial cells. The higher RSR of mitochondria and Golgi apparatus in experimental glial cells depended mostly on the astrocytes, whereas those of nuclei and lysosomes were related first of all with microglial cells. These findings are correlated with present concepts of the complex interdependency between neurons and glia in which mutual regulatory controls and influences are exerted.