Eda-Fujiwara Hiroko, Satoh Ryohei, Hata Yuka, Yamasaki Marika, Watanabe Aiko, Zandbergen Matthijs A, Okamoto Yasuharu, Miyamoto Takenori, Bolhuis Johan J
Laboratory of Behavioral Neuroscience, Faculty of Science, Japan Women's University, Tokyo, Japan.
Graduate School of Human Arts Sciences, University of Human Arts and Sciences, Saitama, Japan.
Sci Rep. 2016 Jan 4;6:18481. doi: 10.1038/srep18481.
Vocalisation in songbirds and parrots has become a prominent model system for speech and language in humans. We investigated possible sex differences in behavioural and neural responsiveness to mate calls in the budgerigar, a vocally-learning parrot. Males and females were paired for 5 weeks and then separated, after which we measured vocal responsiveness to playback calls (a call of their mate versus a call of an unfamiliar conspecific). Both sexes learned to recognise mate calls during the pairing period. In males, but not females, mate calls evoked significantly fewer vocal responses than unfamiliar calls at one month after separation. Furthermore, in females, there was significantly greater molecular neuronal activation in response to mate calls compared to silence in the caudomedial mesopallium (CMM), a higher-order auditory region, in both brain hemispheres. In males, we found right-sided dominance of molecular neuronal activation in response to mate calls in the CMM. This is the first evidence suggesting sex differences in functional asymmetry of brain regions related to recognition of learned vocalisation in birds. Thus, sex differences related to recognition of learned vocalisations may be found at the behavioural and neural levels in avian vocal learners as it is in humans.
鸣禽和鹦鹉的发声已成为研究人类言语和语言的一个重要模型系统。我们研究了虎皮鹦鹉（一种能学习发声的鹦鹉）在对配偶叫声的行为和神经反应方面可能存在的性别差异。将雄性和雌性配对5周后分开，然后我们测量它们对回放叫声（配偶的叫声与陌生同种个体的叫声）的发声反应。在配对期间，两性都学会了识别配偶的叫声。分开一个月后，雄性对配偶叫声的发声反应明显少于陌生叫声，而雌性则不然。此外，在雌性中，与两侧大脑半球高阶听觉区域尾内侧中脑皮质（CMM）中的安静状态相比，对配偶叫声的分子神经元激活显著更强。在雄性中，我们发现CMM对配偶叫声的分子神经元激活存在右侧优势。这是首个表明鸟类中与学习发声识别相关的脑区功能不对称存在性别差异的证据。因此，与人类一样，在鸟类发声学习者中，与学习发声识别相关的性别差异可能在行为和神经层面都存在。
