摘要
应用光镜和电镜放射自显影方法，对成年雄性鸣禽白腰文鸟脑中新生神经元的起源和分布进行了研究。结果发现：①端脑室带区（VZ）中存在不均匀分布的[3H]标记细胞，大量标记细胞分布在瑞脑尾侧新纹状体水平（L1～L14）的VZ，形成标记细胞的“热点”区；②标记细胞经两次有丝分裂后，大约在肌肉注射[3H]的第6天后开始从VZ向外迁移，在30天左右到达目的脑区并分化成为成熟神经元。这些神经元不均匀分布在端脑的全部。新纹状体尾瑞中部（NCM）是新生神经元的富集区；③电镜观察表明，NCM脑区中的新生神经元具有一般神经元特征并与周围神经元形成突触。本实验的结果表明，成年“临界型”鸣禽端脑中的新生神经元可能起源于端脑室带区，大量新生神经元主要分布于NCM，到达目的脑区的新生神经元已经发育成熟并具有功能神经元的特征。
With light and electron microscopic autoradiography, the origination and distribution of the newborn neurons in adult 'critical-period' songbird, Striated Mannikin were studied. The results showed that: (1) Many proliferating cells were distributed unevenly in the ventricular zone(VZ) of telencephalon, and the [3H] labeled cells were found to be populated in the lateral ventricular zone of neostriatum at brain level L12~L14,forming proliferation 'hot spots'; (2) Having underwent mitosis twice, the proliferative cells in the VZ began to migrate laterally 6 days after intramuscular injection of [3H] thymidine, and these migrating precursor cells terminated at their targets and differentiated into new neurons on the 30th day. The newborn neurons distributed throughout the telencephalon, mainly in the neostriatum caudale, and pars medialis (NCM); (3) Ultrastructural observation showed that newborn neurons in the NCM had the same morphologic characteristics as mature neurons and they formed synaptic connections with distant targets. These data suggest that newborn neurons in adult 'critical-period' songbirds are originated only from the ventricular zone of telencephalon and distributed mainly in the NCM, and that they are functional neurons with typical features of mature neurons.
出处
《动物学报》
SCIE
CAS
CSCD
1999年第4期378-384,共7页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金!39570250
39870097
关键词
成年鸣禽
新生神经元
临界型
超微结构
分布
Adult songbird, Newborn neuron, Ventricular zone, Light and electron microscopic autoradiography
