CELL-DEATH DURING DEVELOPMENT OF A FOREBRAIN NUCLEUS INVOLVED WITH VOCAL LEARNING IN ZEBRA FINCHES
CELL-DEATH DURING DEVELOPMENT OF A FOREBRAIN NUCLEUS INVOLVED WITH VOCAL LEARNING IN ZEBRA FINCHES
复制标题
DOI：
10.1002/neu.480200702
复制
发表时间：
1989-10-01
期刊：
影响因子：
--
通讯作者：
SENGELAUB, DR
中科院分区：
文献类型：
--
作者：
BOTTJER, SW;SENGELAUB, DR
外侧MAN(新纹状体前部的大细胞核)是一种前脑核，已知只有在学习过程的有限时期才与幼年雄性斑雀的发声学习有关：LMAN的损伤在50天前完全扰乱斑雀的鸣叫行为，但对年长的幼鸟或成年鸟几乎没有影响。与其他歌曲控制区一样，lMAN的发展被推迟到学习歌曲行为的时候。外侧MAN在25至55天龄之间经历了大量神经元的丧失，这段时间包括发声的初始阶段以及lMAN损伤变得无效的时间间隔。在这项研究中，我们测量了神经元丢失的时间进程和在细胞丢失期间lMAN内固缩细胞的发生率。在20天到35天之间，lMAN的神经元明显丢失，在此之后，成年神经元的数量就建立起来了。20天时固缩的发生率最高，大约在活细胞丢失最明显的时候，这表明lMAN中神经元的丢失可归因于细胞死亡。神经元的丧失早在lMAN的损害在干扰发声行为方面变得无效之前就发生了。因此，在损伤失去效力时(大约50-60天)，在细胞损失期后，lMAN中剩余的神经元显然会经历实质性的功能变化。
Lateral MAN (magnocellular nucleus of the anterior neostriatum) is a forebrain nucleus that is known to be importantly involved with vocal learning in juvenile male zebra finches only during a restricted period of the learning process: lesions of lMAN completely disrupt song behavior in zebra finches prior to 50 days of age but have little or no effect in older juvenile or adult birds. The development of lMAN, as of other song-control regions, is delayed until the time that song behavior is being learned. Lateral MAN undergoes a substantial loss of neurons between 25 and 55 days of age, a time that encompasses initial stages of vocal production as well as the interval during which lMAN lesions become ineffective. In this study, we measured both the time course of neuronal loss and the incidence of pyknotic cells within lMAN during the period of cell loss. There is a pronounced loss of neurons from lMAN between 20 and 35 days, after which the adult number of neurons is established. The incidence of pyknosis is greatest at 20 days, around the time when the loss of live cells is also most pronounced, suggesting that the loss of neurons from lMAN is attributable to cell death. The loss of neurons occurs well before lesions of lMAN become ineffective in disrupting vocal behavior. Thus the neurons remaining in lMAN after the period of cell loss apparently undergo a substantial change in function at the time lesions lose effectiveness (about 50-60 days).