Chronic testosterone treatment impairs vocal learning in male zebra finches during a restricted period of development

摘要: To study the effects of chronic exposure to testosterone on song behavior development, we administered various amounts juvenile male zebra finches during different periods acquisition. We report that development profoundly impairs learning in males. The hormone do not seem be dose related but vary according period life which is administered. Exposure starting before day 40 and lasting until adulthood decreases number syllables birds' repertoire increases phrases per bout singing. In addition these changes “syntactical” features song, acoustic abnormalities are also present males begin receive first month life. Administration only 3 weeks produces has no effect size or structure. Birds receiving between 20 d age develop both a reduced size, their bouts contain normal phrases. produce behavioral abnormalities. These results indicate requires low levels circulating provide support for idea vocal entails progressive sequence events.