The evolutionary conservation of neural mechanisms for forming and maintaining pair bonds is unclear. Oxytocin, vasopressin and dopamine (DA) transmitter systems have been shown to be important in pair-bond formation and maintenance in several vertebrate species. We examined the role of dopamine in formation of song preference in zebra finches, a monogamous bird. Male courtship song is an honest signal of sexual fitness; thus, we measured female song preference to evaluate the role of DA in mate selection and pairbond formation, using an operant conditioning paradigm. We found that DA acting through the D2 receptor, but not the D1 receptor, can induce a song preference in unpaired female finches and that blocking the D2 receptor abolished song preference in paired females. These results suggest that similar neural mechanisms for pair-bond formation are evolutionarily conserved in rodents and birds.

A central tension in pediatric research ethics arises from our desire to protect children from harm while also allowing progress toward discoveries that could improve child health. A prime example of this tension is research on a controversial yet increasingly common practice: the use of cannabis by women to treat nausea and vomiting of pregnancy. Studies of cannabis use in pregnancy face a combination of ethical hurdles because of the inclusion of pregnant women and involvement of a schedule I controlled substance. Given the growing need for research on the safety and efficacy of cannabis for nausea and vomiting of pregnancy, we reflect on the multiple historical contexts that have contributed to the challenge of studying cannabis use during pregnancy and make a case for the ethical rationale for such research.