Primary neurons derived from wildtype mice were co-cultured with astrocytes for 1, 3 and 6 days. Subsequently, the cells were fixed and immunostained with an isoform specific monoclonal antibody against CK-B (21E10). Confocal images display the subcellular distribution of CK-B after A) 1 day, B) 3 days and C) 6 days. Image bars represent 10 μm. D) Lysates were prepared from wildtype and CK-B deficient neurons (7 div) and zymogram analysis was applied to determine enzymatic CK activity.