Induced cell death in a thalamic nucleus during a restricted period of zebra finch vocal development
Induced cell death in a thalamic nucleus during a restricted period of zebra finch vocal development
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在斑胸草雀声音发育的受限时期诱导丘脑核细胞死亡
作者：
F. Johnson;SW Bottjer
前脑核的离散网络是雄性斑胸草雀声音学习和产生的基础。该网络中的三个核团形成了一条对于青少年的声音学习特别重要的神经通路：鸟类纹状体的 X 区投射到前丘脑 (DLM) 的内侧背外侧核，后者又投射到前新纹状体的外侧大细胞核 (IMAN)。幼鸟中任何这些核的损伤都会扰乱正常的发声发育，而成年鸟中的相同损伤对已经学会的鸣叫没有影响。由于大量研究表明，发育中的神经系统中神经元的存活取决于对传出目标的访问，因此我们研究了 DLM 神经元的存活在发声学习过程中受到类似调节的可能性。因此，DLM (IMAN) 的传出目标在不同发声阶段（20、40、60 天和成年）的雄性鸟类中受到电解损伤，并且在损伤后 2、4 或 6 天处死鸟类。 IMAN 的电解损伤去除了 DLM 投射神经元的单个已识别传出目标，并切断了这些神经元的末端分枝。尽管 DLM 在声音发育过程中通常不会丢失神经元，但 20 日龄鸡的 IMAN 损伤在损伤后 4 d 时在整个 DLM 中产生了大量固缩细胞，并且在损伤后 6 d DLM 神经元密度减少了三分之二。相比之下，成年鸟类的 IMAN 损伤对 DLM 中神经元的存活影响很小或没有影响。对 40 日龄鸡的分析显示，与 20 日龄鸡相比，细胞损失显着但较少，而 60 日龄鸡与成年鸡没有什么不同。 DLM 细胞对 IMAN 损伤引起的死亡的脆弱性随年龄而下降，这表明调节 DLM 神经元存活的因素也可能与鸣禽学习发声行为的获得有关。
A discrete network of forebrain nuclei underlies vocal learning and production in male zebra finches. Three nuclei within this network form a neural pathway that is particularly important for vocal learning in juveniles: area X of the avian striatum projects to the medial dorsolateral nucleus of the anterior thalamus (DLM), which in turn projects to the lateral magnocellular nucleus of the anterior neostriatum (IMAN). Lesions of any of these nuclei in juvenile birds disrupt normal vocal development, whereas the same lesions in adult birds have no effect on already-learned song. Because numerous studies have shown that neuronal survival in the developing nervous system depends on access to efferent targets, we have investigated the possibility that the survival of DLM neurons is similarly regulated over the course of vocal learning. Thus, the efferent target of DLM (IMAN) was lesioned electrolytically in male birds at various stages of vocal development (20, 40, 60 d of age and adult) and birds were killed either 2, 4, or 6 d postlesion. Electrolytic lesions of IMAN removed the single identified efferent target of DLM projection neurons and axotomized the terminal arborizations of these neurons. Although DLM does not normally lose neurons during vocal development, IMAN lesions in 20-d-old birds yielded numerous pyknotic cells throughout DLM by 4 d postlesion and a two-thirds reduction in DLM neuron density by 6 d postlesion. In contrast, IMAN lesions in adult birds had little or no effect on neuronal survival in DLM. Analysis of 40-d-old birds revealed significant but less substantial cell loss than in 20-d-old birds, whereas 60-d-old birds were not different from adults. The age-related decline in the vulnerability of DLM cells to IMAN lesion-induced death suggests that factors that regulate DLM neuron survival may also be involved in the acquisition of learned vocal behavior in songbirds.
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DOI：
10.1002/neu.480200702
发表时间：
1989-10-01
期刊：
JOURNAL OF NEUROBIOLOGY
影响因子：
--
作者：
BOTTJER, SW;SENGELAUB, DR
通讯作者：
SENGELAUB, DR
DOI：
10.1002/neu.480230606
发表时间：
1992-08-01
期刊：
JOURNAL OF NEUROBIOLOGY
影响因子：
--
作者：
NORDEEN, EJ;GRACE, A;NORDEEN, KW
通讯作者：
NORDEEN, KW
DOI：
10.1002/neu.480210112
发表时间：
1990
期刊：
Journal of neurobiology
影响因子：
--
作者：
E. Rubel;R. L. Hyson;D. Durham
通讯作者：
E. Rubel;R. L. Hyson;D. Durham
DOI：
10.1016/0163-1047(90)90797-a
发表时间：
1990-01-01
期刊：
BEHAVIORAL AND NEURAL BIOLOGY
影响因子：
--
作者：
SOHRABJI, F;NORDEEN, EJ;NORDEEN, KW
通讯作者：
NORDEEN, KW
鸡胚体内自然发生和诱导的神经元死亡需要蛋白质和 RNA 合成：细胞死亡基因作用的证据。
影响因子：
2.7
作者：
Oppenheim,RW;Prevette,D;Tytell,M;Homma,S
通讯作者：
Homma,S