The initiation of maternal care in rodents involves a two-step process; first, OT leads to long-term depression in amygdala to suppress social avoidance of infant stimuli (Gur et al., 2014), and next, OT connects with DA through striatal neurons that encode for both OT and dopamine D1 receptors (Olazábal and Young, 2006). This evidence concerns the gene DRD1 and major depressive disorder.