An immunocytochemical investigation of non-neuronal enolase in cerebellum: a new astrocyte marker.

Immunohistochemical methods were used to study in the optical and electron microscopes the localization of the so-called 'non-neuronal enolase' (the alpha apha-isoenzyme) in adult mouse cerebellum. Three separate methods, including a novel modification involving sequential incubation with biotin-conjugated sheep anti-rabbit serum and avidin-conjugated peroxidase to reveal tissue-bound specific antibody, gave similar results. The enolase was found exclusively in astrocytes: astrocyte perikaryal cytoplasm and processes were heavily labelled and nuclei were frequently stained. The extensive network of astrocyte processes in the granular layer and white matter and the Bergmann fibres in the molecular layer are readily visualized by these methods. Neither neurons nor oligodendrocytes were found to be labelled. The results are discussed in relation to the possible existence of a hybrid form of the enolase and the biochemistry of cerebellar glial cells.