Months after the spinal cord is severed in lampreys, the fish can swim again without any therapeutic intervention (Cohen et al., 1989), but they seem unique among vertebrates in being able to spontaneously reconnect damaged neurons. Nevertheless, in the wake of several research breakthroughs, there is more hope than ever for an effective treatment to help severed neuronal pathways in the spinal cord reconnect with their targets. Four main strategies for reconnecting the brain and spinal cord in humans are being investigated (see Figure 1):
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