Similarly, ChABC infusion via osmotic minipump combined with Schwann-cell seeded guidance channels also resulted in significant anatomical evidence of regeneration KU57788 through the graft compared with that seen without ChABC treatment [303]. Furthermore, in a study which combined a Schwann cell bridge, implanted between a thoracic complete transection, with both olfactory ensheathing glia and ChABC (delivered rostrocaudally), an increase in serotonergic fibres (although not those of descending tracts such as CST or reticulospinal
tract fibres) were seen to exit the bridge caudally. This resulted in functional recovery which was absent without ChABC application [304]. It has subsequently been shown that propriospinal interneurones and fibres from various brain stem nuclei, including vestibular, reticular
and raphe nuclei, regenerated through the tissue bridge into the caudal spinal cord [305]. Based on the body of evidence that manipulating the SB203580 research buy ECM with ChABC increases plasticity [121–123,252,255] (reviewed in [46,306]) it has been utilized in combination with rehabilitation/training paradigms. For example, following a C4 dorsal funiculus lesion and ChABC treatment (delivered intraparenchymally rostral and caudal to the lesion followed by five bolus intrathecal infusions on alternative days) a synergistic effect of intensive voluntary forepaw motor rehabilitation and ECM modification was reported (in comparison with either treatment alone) on promoting
recovery of impaired limb function [307]. However, additional locomotor rehabilitation, requiring different sensorimotor skills, was found to negatively affect recovery of the forepaw. This correlates with previous findings in which ‘self-training’ or training on one task can prove detrimental to performance on another following spinal cord injury [308,309]. Following moderate thoracic spinal contusion injury to the mouse, however, a single injection of ChABC into the lumbar enlargement combined with voluntary wheel running rehabilitation did not improve SDHB general motor recovery [310]. Based on the lack of functional effects seen by this group and others following a single intraspinal injection of ChABC [249,264], together with the length of time the enzyme remains active in vivo [271,272] and the time frame in which the ECM is known to remodel following CSPG digestion [164], longer-term administration of ChABC may prove more efficacious in a combined therapy involving ECM modification and rehabilitative training to promote and refine activity-dependent plasticity.