摘要
对鸣禽白腰文鸟 (Lonchurastriata)发声控制核团古纹状体粗核 (robustnucleusofarchistriatum ,RA)的性双态分化过程进行了组织学研究 ,并应用双向神经示踪剂 (biotinylateddextranamine ,BDA) ,追踪新纹状体外侧巨细胞核 (lateralnucleusmagnocellularisofanteriorneostriatum ,LMAN)和高级发声中枢 (highvocalcenter,HVC)与RA建立纤维联系的时间和过程。结果发现 :5～ 3 5日龄段为雌雄RA体积、神经元大小和神经元密度变化最集中的时间。在该时段内 ,RA体积、神经元大小均增加 3～ 4倍 ,而RA神经元密度减少约 4倍。这些变化在雌雄间无显著差异 (P >0 0 5 ,非配对 ,双尾t 检验 ) ,但与RA同LMAN、HVC建立神经联系的时间一致。RA同LMAN、HVC建立联系的时间分别为 5～ 15和 15～ 3 5日龄。 4 5日龄后 ,RA体积大小在雌、雄间出现显著差别 (P <0 0 5 )。 4 5～ 60日龄为雌鸟神经元凋亡数量最多时期 ,4 5和 60日龄神经元凋亡数分别为 19 4± 8 0和 17 9± 8 2 (× 10 3/mm3)。结果提示 :4 5日龄后雌雄鸟RA体积和神经元凋亡的变化可能是鸣禽发声核团性双态产生的主要原因。
Songbirds exhibit some of the most extreme sex dimorphism in the brain of all vertebrates. The mechanisms that control this sexual dimorphism are poorly understood. By using histological and neural tract tracing methods, we studied the development of the sexual dimorphism of a forebrain nucleus involved in the song control, the robust nucleus of the archistriatum (RA) of songbird, Striated mannikin ( Lonchura striata ). We found: (1) The outline of RA could be first distinguished from its surroundings around 5 days post hatch (D5) in both female and male birds. From D5 to 45, the RA volume increased gradually. The growth in RA volume was occurred significantly during D5 to 25 ( P <0 05, t test, unpaired, two tail). The differences in RA volume were not significant from D5 to 35 between male and female Striated mannikin ( P >0 05). During development the RA volume for females became smaller and smaller after D45, whereas the RA volume for males continuously increased. As a result, the RA volume in females was only one third of that in males at D120; (2) There was no significant difference in the neuron size in the RA between the sexes during D5 to D35 ( P >0 05). At D5 the neurons size of RA in both females and males remains essentially the same, 15 7 μm 2±5 2 μm 2. However, the neuron sizes in RA were 5 6 and 5 5 times larger at D45 than their sizes at D5, respectively, for the males and the females. The neuron size in RA for both females and males no longer increased after D45. The larger neurons with 80 μm 2 cell size in RA disappeared gradually after D 45 and they were nearly absent in females by D120. The neuron size was 109 μm 2±5 2 μm 2 in male RA and 60 9 μm 2±10 0 μm 2 in female RA at D120, respectively. The neuron size in RA was nearly two times larger in males than in females at D120; (3) The neuron density in RA decreased from 1 18×10 5 to 1 98×10 4 per mm 3 and from 1 21×10 5 to 1 17×10 4 per mm 3, respectively, for the females and the males du
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2001年第5期535-541,T001,共8页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金资助项目 (No .39870 0 97
No.39960 0 14 )~~
