COMPARTMENTATION OF THE CEREBELLAR CORTEX BY PROTEIN-KINASE-C DELTA

Six isozymes of protein kinase C were analysed in the rat cerebellum u sing immunohistochemistry. The results revealed a non-uniform distribu tion of protein kinase C delta among Purkinje, basket, and stellate ce lls. Serial-section mapping of the delta immunoreactivity revealed tha t (i) the number and intensity of labeled Purkinje cells increased fro m rostral to caudal while labeled basket-stellate cells decreased caud ally; (ii) the majority of Purkinje cells were labeled in the nodulus, flocculus, and paraflocculus while the anterior lobules were mostly n egative; and (iii) labeled Purkinje cells formed distinct parasagittal bands in lobules 6-9 of the paravermis and vermis. The banding of pro tein kinase C delta within subsets of Purkinje cells suggests units of cerebellar circuitry with specific signaling properties through prote in phosphorylation. The visual-vestibular regions of the cerebellum co ntained the highest amount of the isozyme.