Blood and cerebrospinal fluid samples will be subjected to the procedures required for the isolation of the different components immediately after the withdrawal. Subsequently, the levels of microRNAs, cytokines, chemokines, cell growth factors, neuronal damage markers (tau, phosphorylated and truncated tau, neurofilaments) and mitochondrial (lactate) and free d-amino acids (Objective 1) will be determined. Furthermore, synaptic alterations will be evaluated in the ex vivo chimeric model of MS, using the patch-clamp technique (Objective 2). Genotyping studies will be conducted in order to identify single nucleotide polymorphisms (SNPs) in coding and / or regulating regions of genes (microRNAs or proteins) involved in alterations of the synaptic transmission of MS and its murine experimental model (i.e. SLC1A3 [4], NGFB [15], PDGFA [7], etc.), which correlate with specific clinical parameters (i.e. EDSS, BREMS, disease progression index, MS type, disease activity, etc.) and with the levels of potential biomarkers identified