Activity-dependent distribution of protein kinase C-delta within rat cerebellar Purkinje cells following unilateral labyrinthectomy

Protein kinase C isoforms PKC-delta and PKC-gamma are expressed in Purkinje cells in the uvula-nodulus of the cerebellum. We examined the effect of Pu rkinje cell activity on the transcription, expression and intracellular dis tribution of PKC-delta and PKC-gamma. Relative changes in activity were ind uced by unilateral labyrinthectomy (UL), decreasing the activity of Purkinj e cells on the side of the labyrinthectomy relative to the contralateral si de with intact vestibular input. After a UL, there was decreased immunolabe ling of Purkinje cell axon terminals in the ipsilateral caudal vestibular c omplex by antisera to PKC-delta, but not PKC-gamma. Western blots prepared from the uvula-nodulus and caudal vestibular complex showed an increase in the cytosolic PKC-delta and a decrease in membrane-associated PKC-delta in the ipsilateral uvula-nodulus 12-48 h after the UL. Hybridization histochem istry and semiquantitative reverse transcription polymerase chain reaction (RT-PCR) demonstrated no change in transcription of PKC-delta mRNA in the u vula-nodulus 1-240 h after unilateral labyrinthectomy. We conclude that bot h PKC-delta and PKC-gamma are constitutively expressed in Purkinje cells. T he targeting of PKC-delta, but not PKC-gamma, to Purkinje neuron synaptic t erminals is influenced by activity.