The above results are of substantial interest since the dominating role of the 5-HT2AR protomer, a 5-HT receptor known to enhance depression, may do so in part by reducing OXTR protomer signaling, which improves social behaviors and mood, provided that this antagonistic allosteric cross-talk also exists in the brain OXTR heteroreceptor complexes [65,66,67,68]. Here, OXTR is linked to major depressive disorder.