Brain levels of most sphingomylein species were increased and most ceramides species decreased following long-term inhibition of nSMase2. Summary data showing the effects of inhibiting nSMase2 on sphingomyelin and ceramide content of (A, B) hippocampus, (C, D), striatum, (E, F) cortex and (G, H) cerebellum (n = 12 treated with GW4869, 13 treated with vehicle). * = p < 0.05; ** = p < 0.01 decreased compared with control, # = p < 0.05; ## = p < 0.01 increased compared with control. ANOVA with Tukey post hoc comparisons. Values represent mean ± S.D.