Neuronal Mechanism of Song Control System in Bird.

鸟鸣是一种刻板的行为，但它的发展取决于感官反馈和学习。鸣唱是在鸟类个体发育过程中逐渐发展起来的。当歌曲的所有方面，包括它的持续时间，频率范围和组成声音的形式，都变得固定时，这首歌被称为“结晶”。尽管成年鸟类每年都会经历一个类似于亚鸣唱和可塑鸣唱年龄相结合的阶段，但它们在余生中每年都会忠实地重现结晶化的歌声。歌声是一种受激素控制的行为。鸟儿对睾丸激素的反应是鸣叫。对歌唱过程中鸣唱系统神经元的记录表明，HVc和RA这两个前脑核团依次构成了发声系统的前脑运动通路。血管催产素（vasotocin，AVT）是一种神经肽，对记忆和学习有重要的生理作用。应用免疫组织化学技术对斑胸草雀和孟加拉雀脑内AVT细胞和纤维进行了定位研究。Vabotocin免疫反应（ir-VT）细胞和纤维形成了一个经典的下丘脑神经垂体系统的男性和女性。Ir-VT纤维仅见于男性的鸣唱控制系统的HVc和RA区。在外侧隔和间脑背侧，VT免疫反应阳性率男性高于女性。

Birdsong is a stereotyped behavior, yet its development depends on sensory feedback and learning. Song develops gradually during a birds ontogeny. When all aspects of song, including its duration, frequency range, and the form of the component sounds, become fixed, the song is said to be "Crystallized". Although adult birds annually go through a phase akin to combination of subsong and plastic song ages, they faithfully reproduce the crystallized song every year for the rest of their life.Song is a hormonally controlled behavior. The birds sang in response to testosterone. Recording to neurons within the song system during singing shows that two of the forebrain nuclei, HVc and RA, in that order, constitute the forebrain motor pathway in vocal system for song control. One of neuropeptides, vasotocin(AVT)is known to have powerful physiological effect with regards to memory and learning. We examined localization of AVT cells and fibers in the zebra finch and bengalese finch brain with immunohistochemical technique. Vabotocin immunoreactive(ir-VT)cells and fibers formed a classical hypothalamic neurohypophyseal system in males and females. Ir-VT fibers were found in HVc and RA regions of song control system of only male. In lateral septum and dorsal diencephalon, the VT immunoreactivity was higher in males than in females.