Figure 1.

Schematic sequence of the model of partial sciatic nerve injury to study collateral sprouting of sensory neurons.

L3 and L4 DRG and spinal nerves and the sciatic nerve trunk are shown. Before L3 spinal nerve transection, intact L3 spinal nerve axons look rounded and some of them myelinated (A). Few days after injury, damaged L3 spinal nerve axons initiate the Wallerian degeneration program and axons lose their normal structure (B). Fourteen days after transection, collateral sprouts of intact L4 spinal nerve are found in L3 spinal nerve degenerated areas (C). To study the molecular mechanisms of collateral sprouting, after L3 spinal nerve injury, the L4 DRG can easily be removed and used for transcriptomic analysis (C). DRG: Dorsal root ganglion.