[Frontiers in Bioscience S3, 846-856, June 1, 2011]

The good, the bad and the ugly. Macrophages/microglia with a focus on myelin repair

Axinia Doring1, Voon Wee Yong1

1University of Calgary, Department of Clinical Neuroscience, Hotchkiss Brain Institute, Calgary, Canada


1. Abstract
2. Introduction
3. Representation of Macrophages/Microglia in the CNS in health and after Injury
4. Detriments of Macrophages/Microglia activity after CNS Injury
5. Benefits of Macrophages/Microglia activity after CNS Injury
6. Dichotomy of Macrophages/Microglia activity after CNS Injury
7. Promotion of Macrophages/Microglia activity after CNS Injury
8. Conclusion
9. Acknowledgements
10. References


A feature of most neurological disorders is demyelination, whereby myelin is lost from axons partly through stripping by macrophages/microglia. Spontaneous remyelination by oligodendrocytes that mature from oligodendrocyte precursor cells occurs following demyelination, even in the chronic inflammatory disorder of the central nervous system, multiple sclerosis. If remyelination does not occur or is prevented, then one consequence besides the loss of saltatory nerve conduction is the degeneration of axons. Thus, promoting remyelination is a desired result. In this article, we review the data that despite a reputation as "bad" factors for CNS wellbeing, including the promotion of neuroinflammation and demyelination, some aspects of macrophages/microglia activity are indeed "good", and can engender repair from the "ugly" phenomenon of demyelination. We discuss factors that help promote the benefits of macrophages/microglia activity for remyelination.