RESUMO
The production of labeled precursors in adult female Melanocorypha mongolica and Lonchura striata were investigated by using bromodeoxyuridine (BrdU) and ABC immunohistochemical method to mark new synthesized DNA. Then, the distribution of newborn precursor was compared between the two kinds of songbirds. The results reveal that: 1) During 1-4 days after BrdU intramuscular injection, there were a great number of labeled cells in lateral ventricular zone (LVZ),and forming proliferation 'hot spots' in the ventricular zone (VZ) of the ventral striatum and neostriatum. The newborn labeled precursor in the two adult songbirds originated from ventricular zone in telencephalon. In the two adult songbirds, there were a great number of labeled precursors in the ventricular zone (VZ) of the medial striatum and lateral striatum and forming proliferation 'the first hot spots'; in the top of LVZ and forming proliferation 'the second hot spots'. In Melanocorypha mongolica,there were a lot of labeled precursors in the tail of VZ in lateral striatum and forming proliferation 'the third hot spots'. But in Lonchura striata, there were a small number BrdU labeled precursors in the tail of VZ. 2) From 5 days after BrdU intramuscular injection in Melanocorypha mongolica, a great number of labeled precursors in the LVZ began to migrate into the other region of the telencephalon. During 5-30 day after BrdU intramuscular injection, some of labeled cells emerged into the nucleus of high vocal center (HVc), and robust nucleus of the archistriatum (RA) in Melanocorypha mongolica. But there were no BrdU labeled cells in the HVc and RA in female Lonchura striata during the 30 days after BrdU intramuscular injection. New neurons, which are added to HVc and RA continuously in adult female Melanocorypha mongolica, may be necessary for learning the new songs of adult male birds. HVc and RA of adult Lonchura striata have few new neurons to replace older neurons.
