 Vasopressin is known to regulate many social behaviors including pair bonding and social recognition.While male rats typically have higher levels of vasopressin in the amygdala, MeCP2 reduction during the first 3 days of life causes a lasting reduction of vasopressin to female typical levels in this brain region that lasted through adulthood.Male rats with reduced MeCP2 levels also show a significant reduction of AR at two weeks following infusion, but this effect is gone by adulthood.