White Matter Plasticity Keeps the Brain in Tune: Axons Conduct While Glia Wrap
- 1Montreal Neurological Institute, Mcgill University, Canada
- 2Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, United Kingdom
Precise timing of neuronal inputs is crucial for brain circuit function and development, where it contributes critically to experience-dependent plasticity. Myelination therefore provides an important adaptation mechanism for vertebrate circuits. Despite its importance to circuit activity, the interplay between neuronal activity and myelination has yet to be fully elucidated. In recent years, significant attention has been devoted to uncovering and explaining the phenomenon of white matter plasticity. Here, we summarize some of the critical evidence for modulation of the white matter by neuronal activity, ranging from human diffusion tensor imaging studies to experiments in animal models. These experiments reveal activity-dependent changes in the differentiation and proliferation of the oligodendrocyte lineage, and in the critical properties of the myelin sheaths. We discuss the implications of such changes for synaptic function and plasticity, and present the underlying mechanisms of neuron-glia communication, with a focus on glutamatergic signalling and the axomyelinic synapse. Finally, we examine evidence that myelin plasticity may be subject to critical periods. Taken together, the present review aims to provide insights into myelination in the context of brain circuit formation and function, emphasizing the bidirectional interplay between neurons and myelinating glial cells to better inform future investigations of nervous system plasticity.
Keywords: activity-dependent, myelin, oligodendrocites, Axon, Glutamate, plasticity, conduction velocity
Received: 16 Jun 2018;
Accepted: 30 Oct 2018.
Edited by:Egidio D‘Angelo, University of Pavia, Italy
Reviewed by:Lester Melie-Garcia, Lausanne University Hospital (CHUV), Switzerland
Davide Lecca, Università degli Studi di Milano, Italy
Copyright: © 2018 Chorghay, Káradóttir and Ruthazer. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Edward S. Ruthazer, Montreal Neurological Institute, Mcgill University, Montreal, Quebec, Canada, firstname.lastname@example.org