LEP and obesity due to melanocortin 4 receptor deficiency: In addition, the fact that leptin insensitivity was observed in VMH neurons of LepR-Cre Slc7a5fl/fl mice before the onset of obesity (Figure 5) alongside impairment in BCAA uptake in the VMH (Figure 2) led us to examine whether LAT1 in LepR-expressing VMH neurons was indeed important for the control of energy and bone homeostasis.