Lack of labelling of microglial cells following microinjection of [3H] ?-alanine: An electron microscopic autoradiographic study

Abstract
Following axotomy of the facial nerve, the uptake of [3H] β-alanine into different types of glial cells in the facial nucleus was studied by autoradiography. A marked proliferation of microglial cells, predominantly in a satellite position to neurons, was accompanied by a localization of [3H] (β-alanine over astrocytes and oligodendrocytes but not over microglial cells. Microglial cells therefore appear to be a functionally distinct cell type and should not be classified with the macroglia.