context-dependent links between song production and opioid-mediated analgesia in male european starlings (sturnus vulgaris)上下文相关的歌曲之间的联系生产和opioid-mediated镇痛在男性欧洲椋鸟(sturnus寻常的).pdfVIP

Context-Dependent Links between Song Production and Opioid-Mediated Analgesia in Male European Starlings (Sturnus vulgaris) Cynthia A. Kelm-Nelson*, Sharon A. Stevenson, Lauren V. Riters Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America Abstract Little is known about the neural mechanisms that ensure appropriate vocal behaviors within specific social contexts. Male songbirds produce spontaneous (undirected) songs as well as female-directed courtship songs. Opioid neuropeptide activity in specific brain regions is rewarding, at least in mammals, and past studies suggest that the opioid met-enkephalin in such areas is more tightly linked to undirected than female-directed song. Recent data using a song-associated place preference paradigm further suggest that production of undirected but not directed song is tightly linked to intrinsic reward. Opioids have analgesic properties. Therefore, if production of undirected song is closely linked to opioid-mediated reward, the production of undirected but not directed song should be associated with analgesia. Consistent with this prediction, in male starlings we identified a positive correlation between analgesia (decreased reactivity to a hot water bath) and undirected song (in non-breeding season condition males in affiliative flocks) but not female-directed song (in breeding season condition males presented with females). When breeding condition males were divided according to social status, a negative correlation was found in subordinate males (i.e. males that failed to acquire a nest box). These data are consistent with the hypotheses 1) that the production of undirected song is facilitated or maintained by opioids (and/or other neuromodulators that also induce analgesia) and 2) that production of female-directed song is n