Nerve fibers can't grow along injured spinal cords because scar tissue gets in the way.

神经纤维没法沿着损伤的脊髓生长，因为伤处有疤痕组织阻挡。

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Stem cell therapy, which is entering early-stage human trials, turns stem cells into other cell types, like healthy nerve cells, to treat spinal cord injury, blindness and other ailments.

正在进行人体前期试验的干细胞疗法，可以通过干细胞替代的方式，治疗脊髓损伤、眼盲和其他疾病。

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From the infection site, it moves through nerve cells toward the spinal cord and brain.

狂犬病病毒会从感染处通过神经细胞扩散并感染脊髓与大脑。

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It is not yet known whether it is possible to generate extensive neuroplasticity in a system that has been injured for a long time and now contains many more complications such as abundant scar tissue, large holes in the spinal cord and where many spinal nerve cells and long range nerve fibres have died or degenerated.

BBC: 'Hope' for the paralysed?

Even nerve cells in the spinal column might be regenerated, allowing the paralyzed to walk again.

CNN: GROWN TO ORDER

For example, fresh nerve cells could alleviate spinal-cord injuries, or newly made heart cells could repair a site scarred by a heart attack.

WSJ: Experiment Brings Human Cloning One Step Closer