BDNF and obesity due to melanocortin 4 receptor deficiency: Indeed, a similar phenomenon was found in BDNF studies: deletion of Bdnf in the adult PVH caused much more robust hyperphagia and obesity than deletion of Bdnf in the PVH during embryonic development using Cre recombinase driven by Sim1 promoter (Balthasar et al., 2005; An et al., 2015).