SV2B and obesity due to melanocortin 4 receptor deficiency: Among the presynaptic vesicle proteins analyzed, i.e., synaptic vesicle glycoproteins 2A and 2C (SVA and SVC, respectively) (Figure S1), only synaptic vesicle glycoprotein 2B (SV2B) showed alterations related to obesity and age (Figure 6).