The role of sex steroid and telecephalic nuclei.HVc of the song-pathway in songbird.

雄性孟加拉雀有两种鸣唱行为（直接鸣叫.DS和非直接鸣叫.US）。为了检验这是否是由于睾酮（T）依赖性的差异，我们研究了2-4个月期间粪便T水平以及DS和US的量的发育变化。DS出现在83 - 94日龄之间，在粪便T水平升高后4-16日龄。2，我们确定血浆雌二醇（E_2）水平为SD的内分泌因子，雄性求偶行为为SD的释放因子，当E_2水平较低时，SD持续时间较短，而当E_2水平较高时，SD持续时间并不一定较长。视觉刺激和听觉刺激同样能有效地诱发SD。我们观察了成年雄性大鼠HVc内微量注射兴奋性神经递质后的长期效应，头端核团的HVc可以控制鸣唱音节的顺序，而RA核团可以编码每个音节的语音特性。

1, The male Bengalese finch has two types of song behavior (direct song.DS and undirect song.US).In order to examine whether this results from a difference in testosterone (T) dependency, we studied developmental changes in the fecal T level and the amounts of DS and US during the 2-4 month period.DS appeared between 83 and 94 days of age 4-16 days after a rise in the facal T level.2, We settled plasma level of estradiol (E2) as endocrine factor of SD,and settled male courtship behavior as releasing factor of it.When E2 level was low, duration of SD was short, but duration of SD was not always long though E2 level was high.Visual stimuli of male was also effective to elicit SD as well as auditory stimuli.3, To identify the site for sequencing of consecutive syllables, we examined long-lasting effects after a microinjection of excitofoxic agent into HVc of male adults.The HVc of telecephalic nuclei could control the sequence of song syllables, while RA nuclei could encode phonetic properities of each syllable.