SYP and myeloid sarcoma: To study the effect of MS on the brain, specifically the hippocampal inflammatory response during adolescence, we examined: (i) the anxiety- and depressive-like behavior, and the spatial memory; (ii) the expression of genes involved in inflammation-induced depression and synaptic dysfunction in hippocampus (Cox-2 (Muller, 2019), 5ht6r (Rasenick, 2016) and Synaptophysin (Cui et al., 2020)); and (iii) the regional hippocampal microglia activation (in DG, CA1 and CA3) and the hippocampal cytokine concentrations in both female and male mice at 6 weeks of age.