Brain aromatase, 5 alpha-reductase, and 5 beta-reductase change seasonally in wild male song sparrows: relationship to aggressive and sexual behavior.
Brain aromatase, 5 alpha-reductase, and 5 beta-reductase change seasonally in wild male song sparrows: relationship to aggressive and sexual behavior.
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野生雄性歌麻雀的脑芳香酶、5α-还原酶和 5β-还原酶随季节变化：与攻击性和性行为的关系。
DOI：
10.1002/neu.10225
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Saldanha,ColinJ
中科院分区：
文献类型：
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作者：
Soma,KiranK;Schlinger,BarneyA;Wingfield,JohnC;Saldanha,ColinJ
在许多物种中，领地性仅在繁殖季节表达，此时血浆睾酮（T）升高。相反，在歌麻雀（Melospiza melodia morphna），男性是高度领土在繁殖（春季）和非繁殖（秋季）季节，但不是在蜕皮（夏末）。在秋季，血浆性类固醇是基础的，去势对攻击性没有影响。然而，抑制芳香化酶减少非繁殖攻击，这表明神经类固醇代谢可能调节攻击行为。在野生雄性歌雀中，我们研究了芳香酶mRNA的神经分布以及芳香酶、5α-和5β-还原酶活性的季节性变化，这些酶分别将T转化为17β-雌二醇、5α-二氢睾酮（5α-DHT，一种有效的雄激素）或5β-DHT（一种无活性代谢物）。酶活性测定间脑，腹内侧端脑（vmTEL，其中包括鸟类杏仁核），尾内侧新纹状体（NCM），在春季，换羽，或秋季捕获的鸟类海马。芳香化酶和5β-还原酶以区域特异性方式季节性变化。间脑芳香化酶在春季高于换羽和秋季，类似于男性性行为的季节变化。芳香化酶活性的vmTEL是高的春季和秋季，但显着减少蜕皮，类似的季节性变化的侵略。5β-还原酶在蜕皮期间没有升高，这表明蜕皮期间的低攻击性不是雄激素失活增加的结果。这些数据强调了神经类固醇代谢与自由生活动物自然行为表达的相关性。© 2003 Wiley Periodicals，Inc. J Neurobiol 56：209-221，2003
In many species, territoriality is expressed only during the breeding season, when plasma testosterone (T) is elevated. In contrast, in song sparrows (Melospiza melodia morphna), males are highly territorial during the breeding (spring) and nonbreeding (autumn) seasons, but not during molt (late summer). In autumn, plasma sex steroids are basal, and castration has no effect on aggression. However, inhibition of aromatase reduces nonbreeding aggression, suggesting that neural steroid metabolism may regulate aggressive behavior. In wild male song sparrows, we examined the neural distribution of aromatase mRNA and seasonal changes in the activities of aromatase, 5α‐, and 5β‐reductase, enzymes that convert T to 17β‐estradiol, 5α‐dihydrotestosterone (5α‐DHT, a potent androgen), or 5β‐DHT (an inactive metabolite), respectively. Enzyme activities were measured in the diencephalon, ventromedial telencephalon (vmTEL, which includes avian amygdala), caudomedial neostriatum (NCM), and the hippocampus of birds captured during spring, molt, or autumn. Aromatase and 5β‐reductase changed seasonally in a region‐specific manner. Aromatase in the diencephalon was higher in spring than in molt and autumn, similar to seasonal changes in male sexual behavior. Aromatase activity in the vmTEL was high in both spring and autumn but significantly reduced at molt, similar to seasonal changes in aggression. 5β‐Reductase was not elevated during molt, suggesting that low aggression during molt is not a result of increased inactivation of androgens. These data highlight the relevance of neural steroid metabolism to the expression of natural behaviors by free‐living animals. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 209–221, 2003