Proposed mechanisms involved in the increase of SMN expression induced by ERK inhibition in the spinal cord of severe SMA-like mice. A, Activation profile of ERK/Elk-1 and AKT/CREB signaling pathways in lumbar spinal cord of vehicle-treated SMA-like mice compared with control. Large characters indicate activated molecules. B, Activation profile of ERK/Elk-1 and AKT/CREB signaling pathways in lumbar spinal cord of U0126-treated SMA-like mice compared with vehicle-treated SMA-like mice. Large characters indicate activated molecules.