Keratan Sulfate Proteoglycans in Plasticity and Recovery after Spinal Cord Injury

A, Descending supraspinal tracts (corticospinal, rubrospinal, etc.; blue) synapse on premotor interneurons and motor neurons in the spinal cord (both in green) controlling locomotion. B, Contusion injury largely severs these connections and disrupts axonal conduction in spared fibers (red). Limited plasticity (pink) may allow some restoration of function through propriospinal neurons (purple), which can form relay circuits. C, Blocking the inhibitory action of KSPGs with K-II treatment could enhance this plasticity or promote branching past the lesion to reestablish direct supraspinal input. Additionally, K-II might also promote conduction in spared fibers.