10种鸣禽控制鸣啭神经核团大小与鸣唱复杂性的相关性

为进一步揭示鸣禽鸣唱行为的神经生物学机制 ,本实验先对 8个科 10种鸣禽的鸣唱行为进行了观察和录音 ,并借助声谱软件分析了每种鸣禽的鸣唱复杂性。鸣唱语句复杂性的评价指标包括 :短语总数、每个短语中所含的平均音节数及音节种类数、所有短语的总音节数及音节种类数、最长短语的音节数及音节种类数。然后 ,测定了前脑三个鸣啭学习控制核团和一个与发声无关的视觉参考核团体积 ,分析了鸣唱语句复杂性和这些核团大小间的相关关系。结果表明 :1)HVC和HVC/Rt与 7种鸣唱语句复杂性指标无关 ;RA和RA/Rt与总音节种类数相关 ;AreaX与总音节数及音节种类数相关 ;2 )HVC/RA和HVC/X比值与多个鸣唱语句复杂性指标相关。结果提示 :鸣禽鸣唱复杂性不同特征可能受不同神经控制

Song complexity is associated with the volume of brain song-control nuclei in ten oscine species

In the songbird forebrain, song nuclei HVC (high vocal center), RA (the robust nucleus of the arcopallium) and X (Area X) play a crucial role in song acquisition. To further understand the neural mechanism of song behaviors in songbird vocal system, the song behaviors of 10 oscine species from 8 families during February and October were observed and the songs of these oscine species were recorded. Using a software of sund analysis, we analyzed the song complexity for every oscine species. We counted the numbers of following song features: total phrase(TP),syllables in all the phrases(SAP),syllable types in all the phrases(STAP),syllables in the longest phrase (SLP) and syllable types in the longest phrase (STLP), and counted the average number of syllables per phrase (ANSPP)or syllable types per phrase (ANSTPP). After finishing the recording, we measured the volumes of forebrain song control nuclei: HVC, RA and Area X and a control nucleus, rotundus nucleus (Rt) (a diencephalic nucleus involving in visual relay). The results were as follows: 1) There was no significant correlation between either the absolute sizes of HVC or the size ratios of HVC to Rt and song complexity. Unlike HVC, the absolute sizes of RA and the size ratios of RA to Rt were significantly related to the sum of syllable types in all phrase types, whereas the absolute sizes of area X were significantly related to the sum of syllables or syllable types in all phrase types.2) The size ratios of HVC to RA or HVC to Area X showed a significant correlation to several measurements of song complexity. These results suggest that different measurements of song complexity are subject to varied neural control