Completely transected rat lower thoracic spinal cord was bridged either immediately or lingeringly by microsurgically linking T7 intercostal nerves to L3 dorsal root stumps to establish a bridged bypass.The surgical sites were treated locally with a neurotrophin/growth factor cocktail.Following the surgery, partial hind limb locomotion and visceral function were gradually recovered.Regenerating nerve fibers were then traced to pass through linking sites, grow into L3 dorsal root stumps, enter the spinal cord and eventually contact with neurons in the gray matter of the spinal cord between L2 and L4.Electrostimulating bridged nerves could trigger evoked potentials in sciatic nerve, bladder, and colon, and induce hind limb motions.After the bridged nerves transected, the evoked potentials and hind limb locomotion disappeared, urinary retention and feces incontinence occurred again.Our observations demonstrate that physical and functional linkages between the segments of injured spinal cords have been established by bridging by-pass.This is first evidence that the peripheral nerves grow into the central nerve system.More importantly, this innovative strategy is potentially applicable for clinic.