title: Quantifying the early stages of remyelination following cuprizone-induced demyelination.
abstract: The demyelinating toxin cuprizone is used increasingly in mouse studies of central nervous system remyelination. The value of this model for such studies depends on an accurate description of its quantifiable features. We therefore investigated histology and ultrastructure during the early oligodendrocyte differentiation phase of remyelination in mice given cuprizone and allowed to recover for 2 weeks. Limiting the dose of cuprizone to 0.2% overcame significant mouse morbidity and weight loss seen with a 0.4% dose, but the distribution of cuprizone-induced demyelination was anatomically variable. The caudal corpus callosum and dorsal hippocampal commissure mostly demyelinated at this dose, but the rostral corpus callosum and rostral cerebellar peduncles did not. This variable response, together with small axon diameters and hence thin myelin sheaths, hindered analysis of the progress of early remyelination. The proportion of myelinated and unmyelinated axons in defined regions followed expected trends, but there was pronounced variation between animals. Furthermore, group mean G ratios did not change as expected during the early stages of remyelination, and regression analysis revealed a complex relationship between axon diameter and myelin sheath thickness during this period. We also noted axonal pathology that persisted for at least 2 weeks after cuprizone withdrawal.
authors.affiliation: Department of Clinical Veterinary Medicine and Cambridge Centre for Brain Repair, University of Cambridge, United Kingdom.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Stidworthy
authors.forename: Stephane
authors.initials: S
authors.lastname: Genoud
authors.forename: Ueli
authors.initials: U
authors.lastname: Suter
authors.forename: Ned
authors.initials: N
authors.lastname: Mantei
authors.forename: Robin J M
authors.initials: RJ
authors.lastname: Franklin
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism / Q000473:pathology; D002614:Chelating Agents; D003337:Corpus Callosum / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D003471:Cuprizone; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D016548:Prosencephalon / Q000378:metabolism / Q000473:pathology; D012044:Regression Analysis; D012727:Sex Characteristics; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D003471:Cuprizone