While it is well established that the axons of adult neurons have a lower capacity for regrowth, some regeneration of certain CNS populations after
spinal cord injury (SCI) is possible if their axons are provided with a permissive substrate, such as an injured peripheral nerve. While some axons readily regenerate into a peripheral nerve graft (PNG), these axons almost always stall at the distal interface and fail to reinnervate spinal cord tissue. Treatment of the
glial scar at the distal graft interface with
chondroitinase ABC (ChABC) can improve regeneration, but most regenerated axons need further stimulation to extend beyond the interface. Previous studies demonstrate that pharmacologically inhibiting kinesin-5, a motor
protein best known for its essential role in mitosis but also expressed in neurons, with the pharmacological agent
monastrol increases axon growth on inhibitory substrates in vitro. We sought to determine if
monastrol treatment after an SCI improves functional axon regeneration. Animals received complete thoracic level 7 (T7) transections and PNGs and were treated intrathecally with ChABC and either
monastrol or
DMSO vehicle. We found that combining ChABC with
monastrol significantly enhanced axon regeneration. However, there were no further improvements in function or enhanced c-Fos induction upon stimulation of spinal cord rostral to the transection. This indicates that
monastrol improves ChABC-mediated axon regeneration but that further treatments are needed to enhance the integration of these regrown axons.