The entire carcass of cattle not inspected and passed for human consumption is also prohibited, unless the cattle are less than 30 months of age, or the brains and spinal cords have been removed.

In able-bodied people, these "walking circuits" spring into action when they receive a signal from the brain, but if the spinal cord is damaged, the message from the brain never arrives.

The virus moves from a leg bitten by a rabid dog up the long axons leading to the spinal cord, then jumps to dendrites of other nerves and travels up to the brain, where it causes horrific damage.

Many observers do, however, see this research as a step along the road to reconnecting the brains and limbs of those with severed spinal cords, by growing new nerve cells to bridge the gap.

These send signals through the spinal cord to the muscles to give us the ability to move.