The invention relates to a composition comprising: (i) one or more of uridine and cytidine, or salts, phosphates, acyl derivatives or esters thereof and (ii) a lipid fraction comprising at least one of docosahexaenoic acid (22:6 DHA), eicosapentaenoic acid (20:5 EPA) and docosapentaenoic acid (22:5 DPA), or esters thereof, for use in preserving or improving functional synaptic connectivity and/or preserving brain network organization in a subject in need thereof.