Western Blot analysis of rat cortical lysate showing specific immunolabeling of the ~50kD Gap-43 protein phosphorylated at Ser41 using G8990-03 in the first lane (-). Phosphospecificity is shown in the second lane (+) where immunolabeling is completely eliminated by blot treatment with lambda phosphatase (λ-Ptase, 1200 units for 30 min).