All cognitive impairments found in both HSD and OLD groups seem to be intrinsically linked to the reduced expression of Bdnf, a capital factor for neurogenesis, cellular differentiation, and hippocampal plasticity that promotes Ire1α phosphorylation and Xbp1 splicing toward UPR-pro-adaptive responses [74,75,76]. This evidence concerns the gene BDNF and Cognitive impairment.