: Environmental enrichment improves cognitive function and anxiety-like symptoms and decreases neuroinflammation in a focal cortical model of progressive multiple sclerosis

SILVA, BERENICE ANABEL; FERNANDO JUAN PITOSSI; LEAL MARIA CELESTE; MARIA ISABEL FARIAS; CARINA CINTIA FERRARI

Congreso; ECTRIMS 2018; 2018

Background. The beneficial effects of environmental enrichment (EE) were demonstrated in several neurodegenerative diseases, psychiatric disorders, aging and brain injury. The combination of both cognitive and physical activities enhances the cognitive performance in multiple sclerosis (MS) patients (Jimenez-Morales et al., 2017). EE reduce the expression of pro-inflammatory cytokines (mainly IL-1b and TNF-a) in LPS stimulated animals (Williamson et al., 2012). Additionally, EE ameliorates the peripheral and neuroimmune responses and improve remyelination during experimental autoimmune encephalomyelitis (EAE) progression in mice (Souza et al., 2018, Magalon et al., 2007). The chronic expression of interleukin 1beta (IL-1b) in the cortex along with peripheral stimulation induces cognitive impairment, anxiety-like symptoms, neuroinflammation and demyelination that lasts for 50 days (Silva et al., 2018)Aims. The aim of the present work is to study the influence of EE in the recovery of inflammatory focal cortical lesions induced by IL-1b on peripheral stimulated rats. Material and Methods. Adult rats injected in the cortex with adenovirus expressing IL-1b or bgalactosidase as control were peripherally stimulated with the same adenoviruses (Silva et al., 2018). The animals were distributed in either enriched environment or standard cages (SC) for 30 days. The enriched environment includes toys, tunnels, hiding places and running wheels. Therefore, we can evaluate the main enrichment paradigms: social interaction, cognitive and physical enrichment. We performed behavioural tests (novel object recognition, T Maze, sucrose preference, open field) and immunohistochemical analyses of the lesions.Results. EE improves cognitive impairment, anhedonia and reduce anxiety-like symptoms in peripherally stimulated IL-1 injected animals compared to control ones. Additionally, EE statistically attenuates the microglia and astroglia activation along with a diminished demyelination in EE animals compared to SC animals. Conclusions. Environmental enrichment attenuates cortical neuroinflammation and improves cognitive function along with a reduction in anxiety-like symptoms. Therefore, EE may act synergistically with other therapeutic agents to facilitate brain repair and general welfare.