In addition, given that obesity is associated with insulin dysregulation, altered NAc excitatory transmission, cognitive deficits, and some psychiatric diseases (Biessels and Reagan, 2015; Kullmann et al., 2016; Stoeckel et al., 2016), we also determined how high-fat diet-induced obesity alters insulin's ability to influence NAc excitatory transmission. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.