SIM1 and obesity due to melanocortin 4 receptor deficiency: In support, mice (Sim1-Cre:Bdnf lox/lox) with BDNF depletion in Sim1+ cells, which blanket the PVN and represent several molecularly defined neuronal subpopulations, exhibit hyperphagia, obesity, glucose intolerance, and hyperinsulinemia compared to control littermates fed a chow diet [36].