Growing evidence suggests that insulin and leptin play significant physiological roles in cognition (Paz-Filho et al., 2008; Morrison, 2009; Gray et al., 2014; Arnold et al., 2018), and these signaling pathways may be promising therapeutic targets to alleviate cognitive impairment accompanied by obesity and MetS (Mejido et al., 2020). This evidence concerns the gene LEP and metabolic syndrome.