Act locally and think globally: Intracerebral testosterone implants induce seasonal-like growth of adult avian song control circuits
Act locally and think globally: Intracerebral testosterone implants induce seasonal-like growth of adult avian song control circuits
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DOI：
10.1073/pnas.192308799
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发表时间：
2002-09-17
影响因子：
11.1
通讯作者：
Lent, K
中科院分区：
文献类型：
--
作者：
Brenowitz, EA;Lent, K
成年鸣禽鸣唱行为的调节神经回路的形态具有明显的季节性可塑性，主要是对血浆睾酮（T）水平变化的响应。大多数鸣唱核都有雄激素受体。来自端脑核HVc（也称为“高音中枢”）的传入输入对于直接传出靶核RA和X区的季节性生长是必要的。我们在这里问是否T刺激生长的HVc是足以诱导其传出核的增长。在光敏成年雄性白冠麻雀的HVc或RA附近单侧放置脑内T植入物一个月。HVc附近的T植入物使同侧（而非对侧）HVc、RA和X区显著生长，并增加了同侧HVc中的神经元数量。RA附近的T植入物未产生同侧RA、HVc或X区的选择性生长。脑内T植入物没有提高血浆T水平，也没有刺激两个外周雄激素敏感的目标，空洞和泄殖腔隆起的增长。这些结果表明，季节性增长的成人歌曲电路的结果直接作用于HVc，然后刺激RA和X区的增长transsynaptically。
There is pronounced seasonal plasticity in the morphology of the neural circuits that regulate song behavior in adult songbirds, primarily in response to changes in plasma testosterone (T) levels. Most song nuclei have androgen receptors. Afferent input from the telencephalic nucleus HVc (also known as the "high vocal center") is necessary for seasonal growth of the direct efferent target nuclei RA and area X. We asked here whether T-stimulated growth of HVc is sufficient to induce growth of its efferent nuclei. Intracerebral T implants were placed unilaterally near HVc or RA in photosensitive adult male white-crowned sparrows for one month. The T implant near HVc produced significant growth of the ipsilateral (but not contralateral) HVc, RA, and area X, and increased neuronal number in the ipsilateral HVc. The T implant near RA did not produce selective growth of ipsilateral RA, HVc, or area X. Intracerebral T implants did not elevate plasma T levels, nor did they stimulate growth of two peripheral androgen sensitive targets, the syrinx and the cloacal protuberance. These results suggest that seasonal growth of the adult song circuits results from T acting directly on HVc, which then stimulates the growth of RA and area X transynaptically.