Plasticity After Spinal Cord Injury: Relevance to Recovery and Approaches to Facilitate It

Abstract

Summary: Motor, sensory, and autonomic functions can spontaneously return or recover to varying extents in both humans and animals, regardless of the traumatic spinal cord injury (SCI) level and whether it was complete or incomplete. In parallel, adverse and painful functions can appear. The underlying mechanisms for all of these diverse functional changes are summarized under the term plasticity. Our review will describe what is known regarding this phenomenon after traumatic SCI and focus on its relevance to motor and sensory recovery. Although it is still somewhat speculative, plasticity can be found throughout the neuraxis and includes various changes ranging from alterations in the properties of spared neuronal circuitries, intact or lesioned axon collateral sprouting, and synaptic rearrangements. Furthermore, we will discuss a selection of potential approaches for facilitating plasticity as possible SCI treatments. Because a mechanism underlying spontaneous plasticity and recovery might be motor activity and the related neuronal activity, activity-based therapies are being used and investigated both clinically and experimentally. Additional pharmacological and gene-delivery approaches, based on plasticity being dependent on the delicate balance between growth inhibition and promotion as well as the basic intrinsic growth ability of the neurons themselves, have been found to be effective alone and in combination with activitybased therapies. The positive results have to be tempered with the reality that not all plasticity is beneficial. Therefore, a tremendous number of questions still need to be addressed. Ultimately, answers to these questions will enhance plasticity's potential for improving the quality of life for persons with SCI.

One-year clinical study of NeuroRegen scaffold implantation following scar resection in complete chronic spinal cord injury patients

“…Thus, the length of scar was determined in vivo and it was safely removed under neural electrophysiology monitoring in complete SCI patients. For incomplete SCI patients, spontaneous plasticity events in spared neuronal circuits may occur post-traumatically, including intact or injured axon collateral sprouting or synaptic rearrangement (Onifer et al, 2011;Perez, 2015;Tansey, 2010), which may result in scar tissue mixed together with normal neural tissue. For this reason, dissecting scar tissue in incomplete SCI patients is still a challenge.…”

Editorial

“…More regenerated axons exit the peripheral nerve graft and form functional synapses when ChABC is placed at an appropriate target. Importantly, this approach also promotes functional axon collateral and regenerative sprouting, as described in the article by Onifer, Smith, and Fouad [18]. Although there are other impediments to axon regeneration in the injured spinal cord environment and intrinsic to the axons themselves, the glial scar can also be attenuated with cell cycle inhibitors and matrix metalloproteinases inhibitors, which is discussed in the articles by Wu, Stoica, and Faden, as well as by Zhang, Chang, Hansen, Basso, and Noble-Haeusslein [10,11] respectively.…”

“…The article by Onifer, Smith, and Fouad [18] indicates that the underlying mechanisms known to be responsible for these functional changes are collectively referred to as plasticity. This ranges from the properties of spared neuronal circuitries being altered to synaptic rearrangements.…”

“…On the other hand, facilitatory approaches can enhance plasticity and lead to improved function. Onifer, Smith, and Fouad [18] discuss the pros and cons of some activity-based, pharmacological, and gene-delivery approaches that are currently being investigated.…”

Robotic Technology for Spinal Cord Injury: Upper Extremity

“…Bu konuda yeni araştırmalara ihtiyaç vardır, 4. Beyin arayüz cihazları ile oluşan beyindeki reorganizasyonun inhibisyona veya araya girerek yeni uygulamaları öğrenme-yi etkileyebileceği düşünülmektedir.…”