Effects of Induced Depression on the Animal Model of Multiple Sclerosis: An Overlooked Disability
Depression is a common disabling symptom of MS with a lifetime prevalence of 50%.
The aim of this study is to investigate the impact of induced depression on cuprizone mouse model of demyelination.
Mice were divided into cuprizone with no intervention (Cup-O), cuprizone undergoing induced depression (Cup-Dep) and control groups (9 to 10 per group). Depression was induced by repeated open-space forced swim and was implemented 6 days prior to the testing period. Multiple sclerosis was induced by continuously feeding six-week-old C57BL/6 male mice a 0.2% cuprizone-enriched diet. Spatial learning and memory were tested using Morris water maze while rotarod was used to assess motor function.
Cognitive and motor deficits were established in cuprizone mouse model of demyelination as Cup-O had worse results than control group in Morris water maze (p<0.001) and rotarod (p<0.05). Induced depression was seen to exaggerate the aforementioned deficits; Cup-Dep showed a significantly declined performance in Morris water maze (p<0.001) and rotarod (p<0.05) in comparison to Cup-O.
Depression can further worsen the natural disease course of MS model. Therefore depression-ameliorating measures should be considered as a part of MS management plan based on the results of this study.