Reductions in calbindin and NPY markers were found in the frontal cortex of MDD patients (Widdowson et al., 1992; Rajkowska et al., 2007; Maciag et al., 2010; Tripp et al., 2011, 2012), as well as in the PFC and hippocampus of rats submitted to different rodent models of depression, including CUS, BDNF mutant mice, or the Flinders sensitive line of rat (Caberlotto et al., 1999; Nowak et al., 2010; Zadrozna et al., 2011; Melas et al., 2012; Tripp et al., 2012; Czéh et al., 2015, 2018; Banasr et al., 2017; Varga et al., 2017). This evidence concerns the gene BDNF and major depressive disorder.