Zachar Gergely, Montagnese Catherine, Fazekas Emese A, Kemecsei Róbert G, Papp Szilvia M, Dóra Fanni, Renner Éva, Csillag András, Pogány Ákos, Dobolyi Arpád
Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.
MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University and the Hungarian Academy of Sciences, Budapest, Hungary.
Front Neurosci. 2020 Jan 13;13:1401. doi: 10.3389/fnins.2019.01401. eCollection 2019.
The expression of the recently identified neuropeptide, amylin, is restricted in rodents to the postpartum preoptic area and may play a role in the control of parental behaviours and food intake. These processes are substantially different between bird and rodent parents as birds do not lactate but often show biparental care of the offspring. To establish the presence and role of amylin in the bird brain, in the present study, we investigated the distribution of amylin in brains of adult male and female zebra finches in three different reproductive stages (i.e. paired without young, incubating eggs or provisioning nestlings) and in unpaired control birds living in same sex flocks. Amylin mRNA was identified in the hypothalamus of zebra finch by RT-PCR, which was also used to produce probes for hybridisation. Subsequently, hybridisation histochemistry was performed in brain sections, and the labelling signal was quantified and compared between the groups. Amylin showed a much wider brain distribution than that of rodents. A strong and, in some regions, sexually dimorphic label was found in the striatum and several brain regions of the social behavioural network in both males and females. Many regions responsible for the learning of birdsong also contained amylin-positive neurons, and some regions showed sex differences reflecting the fact that vocalisation is sexually dimorphic in the zebra finch: only males sing. Area X (Ar.X), a striatal song centre present only in males, was labelled in paired but not unpaired male. Ar.X, another song centre, the lateral part of the magnocellular nucleus of the anterior nidopallium (lMAN) also contained amylin and had higher amylin label in paired, as opposed to unpaired birds. The wider distribution of amylin in birds as compared to rodents suggests a more general role of amylin in social or other behaviours in avian species than in mammals. Alternatively, parental care in birds may be a more complex behavioural trait involving a wider set of brain regions. The sex differences in song centres, and the changes with reproductive status suggest a participation of amylin in social behaviours and related changes in the singing of males.
最近发现的神经肽胰淀素在啮齿动物中的表达局限于产后视前区，可能在亲代行为和食物摄入的控制中发挥作用。鸟类和啮齿动物亲代之间的这些过程有很大不同，因为鸟类不哺乳，但通常对后代表现出双亲照料。为了确定胰淀素在鸟类大脑中的存在及作用，在本研究中，我们调查了成年雄性和雌性斑胸草雀在三个不同繁殖阶段（即配对但无幼雏、孵卵或育雏）以及生活在同性鸟群中的未配对对照鸟大脑中胰淀素的分布。通过逆转录聚合酶链反应（RT-PCR）在斑胸草雀的下丘脑中鉴定出胰淀素信使核糖核酸（mRNA），该技术也用于制备杂交探针。随后，在脑切片上进行杂交组织化学，并对标记信号进行定量分析，比较不同组之间的情况。与啮齿动物相比，胰淀素在鸟类大脑中的分布要广泛得多。在雄性和雌性的纹状体以及社会行为网络的几个脑区中都发现了强烈的、在某些区域具有性别差异的标记。许多负责鸟鸣学习的区域也含有胰淀素阳性神经元，一些区域表现出性别差异，这反映了斑胸草雀发声具有性别二态性这一事实：只有雄性唱歌。X区（Ar.X），一个仅存在于雄性中的纹状体鸣叫中枢，在配对雄性而非未配对雄性中被标记。另一个鸣叫中枢，前巢核大细胞外侧部（lMAN）也含有胰淀素，并且配对鸟中的胰淀素标记高于未配对鸟。与啮齿动物相比，胰淀素在鸟类中分布更广泛，这表明胰淀素在鸟类物种的社会行为或其他行为中比在哺乳动物中发挥着更普遍的作用。或者，鸟类的亲代照料可能是一个更复杂的行为特征，涉及更广泛的脑区集合。鸣叫中枢的性别差异以及随繁殖状态的变化表明胰淀素参与了社会行为以及雄性鸣叫的相关变化。
