OXTR and Prader-Willi syndrome: Given the manifold effects that physiological and psychological changes such as lactation [63, 64], anxiety [23, 42, 65, 66], maternal separation [67–69] or social isolation [70, 71] have on the number of OT cells, projections and/or OTR expression levels, one could speculate that some of the neonatal clinical manifestations of PWS and SYS also are linked to a dysfunctional OT system, which subsequently results in some of the behavioral abnormalities observed in PWS and SYS patients.