画眉和白腰文鸟端脑新生神经细胞的起源和分布

用5-溴-2-脱氧尿嘧啶(BrdU)标记DNA,ABC免疫细胞化学的方法,观察成年画眉(Garrulax canorus)和白腰文鸟(Lonchura striata)端脑神经前体细胞的产生和分布特点.结果如下:1)胸肌注射BrdU短时程组(存活1~5 d),在端脑室带区外侧壁(LVZ)有大量的新生标记细胞,并在纹状体腹侧的室带区(VZ)形成标记细胞增殖热点;2)注射BrdU长时程组(存活15~30 d),在画眉高级发声中枢(HVc)、HVc壳、高位发声运动中枢———古纹状体栎核(RA)内有一些新生标记细胞,在端脑靠近LVZ的区域有较多的标记细胞,但在白腰文鸟的HVc、HVc壳、RA内未见到标记细胞.结果表明:1)新生神经细胞起源于端脑VZ;2)画眉每天都有一些新生神经前体细胞迁移到HVc和RA内,而白腰文鸟成年后HVc和RA很少有新生神经细胞代替旧的神经元,这与白腰文鸟成年后不需要学习新语句的行为是一致的.推测在画眉HVc和RA内能不断地产生新生标记细胞,这可能与它们需要不断学习新的鸣啭语句有关,而且这些新生的细胞在雄、雌画眉中可能具有同样的功能.

THE ORIGINATION AND DISTRIBUTION OF THE NEWBORN NEURAL CELLS IN TELENCEPHALON OF GARRULAX CANORUS AND LONCHURA STRIATA

The production of labeled cells in adult Garrulax canorus and Lonchura striata is investigated by using bromodeoxguridien(BrdU) and ABC immunohistochemical methods.The results reveal that: 1) During 1~5 day after BrdU intramuscular injection,most of labeled cells are found in lateral ventricular zone(LVZ) and forming proliferation hot spots' in the VZ of the ventral striatum and neostriatum.2) During 15~30 day after BrdU intramuscular injection in Garrulax canorus,some of labeled cells in the LVZ begin to migrate into the nucleus high vocal center(HVc),HVc-shell and robust nucleus of the archistriatum(RA).But there are no BrdU labeled cell in the HVc and RA in Lonchura striata.The present study indicates that: 1) The newborn labeled cells in the two adult songbirds are originated from ventricular zone in telencephalon.2) New neurons,which are added to HVc and RA every day in adult Garrulax canorus,may be necessary for the learning of the new songs.The fact that there are few new neurons replacing older neurons in HVc and RA of adult Lonchura striata may be correlated with the behavior that it does not need to learn new songs.