Immunohistochemical localization of protein kinase C delta during postnatal development of the cerebellum

In cerebella of neonatal rats, immunoreactivity of protein kinase C delta (PKC delta) was moderate to strong in radial glia, Bergmann fibers and astrocytes but was absent in neurons. Beginning on the 7th day, a few small clusters of Purkinje cells expressed weak PKC delta reactions in caudal lobules of the vermis. From 10 to 20 days, clusters of labeled Purkinje cells increased in number, size and intensity while astrocytes and palisades of aligned Bergmann glia gradually diminished in intensity. At 21 days, glial cells had weak reactions while Purkinje and stellate-basket cells had intensity and distribution patterns found in adults. A transient occurrence of PKC delta in glia and later appearance in selective groups of neurons strongly support a significant role for this enzyme in signal transduction.