Effect of C2-ceramide, PACAP, or both on cerebellar granule cell velocity. The curves represent the mean velocity measured in control conditions (black curve, n = 90) or in the presence of 20 μM C2-ceramide (red curve, n = 90), 10-7 M PACAP (blue curve, n = 80), or PACAP plus C2-ceramide (green curve, n = 85). ***, P < 0.001 vs. control; ###, P < 0.001 vs. C2-ceramide.