Cover legend: In the mouse cerebellum, posttetanic potentiation is mediated by calcium-sensitive protein kinase C (PKC) α and β. In PKCα/β double knockouts, antibodies against the only other calcium-sensitive isoform, PKCγ, label postsynaptic Purkinje cells exclusively, suggesting that no calcium-sensitive PKC is expressed in presynaptic granule cells. Nevertheless, granule cells compensate to maintain normal neuronal behavior. For more information, see the article by Fioravante et al. (pages 13004–13009).