CNS Plasticity in Injury and Disease

Copyright © 2016 Brandon A. Miller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Plasticity is a defining characteristic of the central nervous system (CNS). The ability of the CNS to physically change over the life of the organism, including myelination, neu-ronal proliferation, and synaptic changes, remains a topic of research in every subdiscipline of neuroscience from molecular to developmental neuroscience. The lay public also seeks a better understanding of neural plasticity. The recent BRAIN Initiative launched by the United States government (http://braininitiative.nih.gov/about.htm) aims to improve understanding of CNS plasticity by funding projects focused on neuronal circuitry, imaging, and neural modulation. While the CNS has incredible plasticity compared to other organ systems, it also has unique sensitivity to injury. CNS injury and disease, from developmental injuries that occur in utero to environmental insults from toxins and trauma, can have a devastating effect on the organism. Ironically , some of the very mechanisms underlying CNS plasticity confer its sensitivity to injury. For example, neurotransmitter receptors that form the basis for learning and memory can be targets of excess excitatory neurotransmitters that induce cell death in many forms of CNS injury. CNS plasticity allows for recovery from injuries by both adaptation of the organism and cellular regeneration. However, these attempts at regeneration are often incomplete and unsuccessful. This was observed by the Nobel Prize winner Santiago Ramón y Cajal in the early 20th century and continues to be the basis of ongoing research on brain and spinal cord injury. The articles in this special issue illustrate diverse examples of CNS plasticity, both in response to injury and as avenues for recovery. The scope of diseases discussed, motor neu-ron disease, stroke, viral infection, and spinal cord injury, illustrates that a better understanding of basic mechanisms of neural plasticity could lead to better treatments for numerous CNS diseases. Spinal cord injury has received much attention as a target for regenerative therapies. In their paper in the issue, V. Buzoianu-Anguiano and colleagues show that a combination of degenerated peripheral nerve and bone marrow stromal cell transplantation improves axonal regrowth and myeli-nation after spinal cord injury. Other papers in this issue address neural plasticity in diseases where it is less frequently examined. The paper by V. Atluri and colleagues highlights the neuronal …