Abstract
Microglia is increasingly recognized to play a crucial role in the pathogenesis of psychiatric diseases. In particular, microglia may be the cellular link between inflammation and behavioral alterations: by releasing a number of soluble factors, among which pro-inflammatory cytokines, that can regulate synaptic activity, thereby leading to perturbation of behavior. In multiple sclerosis (MS), the most common neuroinflammatory disorder affecting young adults, microglia activation and dysfunction may account for mood symptoms, like depression and anxiety, that are often diagnosed in patients even in the absence of motor disability. Behavioral studies in experimental autoimmune encephalomyelitis (EAE), the animal model of MS, have shown that emotional changes occur early in the disease and in correlation to inflammatory mediator and neurotransmitter level alterations. However, such studies lack a full and comprehensive analysis of the role played by microglia in EAE-behavioral syndrome. We review the experimental studies addressing behavioral symptoms in EAE, and propose the study of neuron-glia interaction as a powerful but still poorly explored tool to investigate the burden of microglia in mood alterations associated to MS.
Highlights
Multiple Sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), which represents the leading cause of non-traumatic disability in young adults in Western countries (Compston and Coles, 2008)
In a study published in 2012, we showed anxiety-like behavior in pre-symptomatic EAE mice (Haji et al, 2012) by open field test (OFT) and elevated plus maze (EPM) behavioral tasks
By studying mice with mild-EAE phenotype, we demonstrated the occurrence of depressive-like (TST and forced swimming tests (FST)) and motivation-based behaviors in the acute phase of the disease in correlation with striatal and hippocampal microgliosis
Summary
Multiple Sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), which represents the leading cause of non-traumatic disability in young adults in Western countries (Compston and Coles, 2008). In addition to physical impairment, MS is frequently associated to mood disorders, like anxiety and depression even in non-disabled patients (Marrie et al, 2009). Recent studies in MS animal model, the experimental autoimmune encephalomyelitis (EAE), have shown that activated microglia, by releasing proinflammatory cytokines, can alter brain synaptic transmission before the appearance of motor symptoms (Centonze et al, 2009, 2010). EAE-behavioral syndrome: implications for microglia conditions in both humans and animal models (Price and Drevets, 2010; Frick et al, 2013), raising the possibility that microglia may have a crucial role in mediating mood disorders in MS. This paper briefly discusses the current studies about anxious- and depressive-like behaviors in the EAE model and proposes the contribution of microglia to EAE mood disorders, as an important but quite unexplored field for future research
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
