SEX STEROID-OPIOID INTERACTIONS ASSOCIATED WITH THE TEMPORAL COMPONENT OF AVIAN CALLING PATTERNS

Isolation from conspecifics in young, precocial birds predictably indu ces distress vocalizations (DV) and androgens change this type of voca lization into male typical ''crowing'' (CR). In addition, opioid pepti des are known to exert potent effects on avian vocal behavior. Here we investigate the organizational and activational correlates of sex-ste roid actions on opioid-receptor organization and their relevance to th e temporal evolution of DV and on. From the effects of pre- and postna tal steroid applications and postnatal [H-3]etorphin binding studies, we find that early steroidal effects become manifested at the behavior al level by changing the characteristic duration of vocalizations. In the male quail this extension of calling duration is accompanied by a clear decrease in opiate binding, whereas in the female there is a mod erate increase in binding sites. The transition from DV to CR (within hours) induced by testosterone is correlated with ''upregulation'' of opiate receptor sites within unilateral brainstem areas of young male quail. Based on these findings, we suggest that organizational steroid effects change the characteristic duration of isolation-induced vocal izations and these effects appear to be manifested at the level of opi oid-receptor distribution. (C) 1996 Academic Press.