Medial amygdala ERα expression influences monogamous behavior of male prairie voles in the field

Formation of long-term pair-bonds is a complex process, involving multiple neural circuits, and is context- and experience-dependent. While laboratory studies using prairie voles have identified the involvement of several neural mechanisms, efforts to translate these findings into predictable field outcomes have been ambiguous at best. Here we test the hypothesis that inhibition of estrogen receptor alpha (ERα) in the medial amygdala of male prairie voles would significantly increase the expression of social monogamy in the field. Prairie vole populations of equal sex ratio were established in outdoor enclosures with males bred to overexpress ERα and display reduced prosocial behavior. Medial amygdala ERα expression was knocked down in half the males per population. Knockdown-males displayed a greater degree of social monogamy in five of the eight indices assessed. This study demonstrates the robust nature of ERα in playing a critical role in the expression of male social monogamy in a ...