MAPT and neurodegenerative disease: While PNN digestion with chondroitinase ABC (ChABC) has enabled restoration of function after focal lesions such as stroke and spinal cord injury (Bradbury et al., 2002; Soleman et al., 2012), it is not established whether re-activation of plasticity by ChABC might restore CNS function following the diffuse neuronal loss and damage that accompanies neurodegenerative disease caused by tau pathology.