RESUMO
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 pair-bond 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.
Assuntos
Proteínas Aviárias/genética , Corte , Dopamina/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Aves Canoras/fisiologia , Vocalização Animal , Animais , Proteínas Aviárias/metabolismo , Condicionamento Operante , Feminino , Tentilhões/fisiologia , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismoRESUMO
An operant conditioning paradigm is used to test the song preference of female zebra finches. Finches are placed in a two-chambered cage with a connecting opening and indicate their preference for a song by landing on a perch within each chamber. By interrupting the infrared beam from a photoelectric sensor above each perch, the bird activates the playback of a song through a speaker located on each side of the cage. Freely available software is used to trigger the song playback from each perch. To determine the song preference of each animal, her chamber preference is first identified by triggering no song playback when she lands on each perch. This chamber preference is then compared to her song preference. A minimum activity threshold is set to ensure the preference is real. Using this method, we show that paired females prefer the song of their partner. This method was used to understand the contribution of dopamine to the formation and maintenance of song preference.