The behavioural ecology of the brain: integrating evolution, behaviour and neuroscience.

大脑的行为生态学：整合进化、行为和神经科学。

• 批准号: RGPIN-2014-03792
• 负责人: Iwaniuk, Andrew
• 金额: $ 5.17万
• 依托单位: University of Lethbridge
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691617
• 关键词: behavioural; ecology; brain; integrating; evolution

The brain differs greatly in size and shape across vertebrate species, but how and why this anatomical diversity exists is largely unknown. My research program addresses this fundamental issue in neuroscience through understanding how brain and behaviour evolve in concert. More specifically, I test the validity of evolutionary theories as applied to the brain through studies within and across species and using a range of neuroscience, animal behaviour and evolutionary biology techniques. In this grant cycle, I will focus on two aspects of reproductive behaviour that are related to how the brain evolves: courtship display and mating system. Courtship is an essential part of reproduction and, in birds, the evolution of different courtship displays is associated with anatomical changes in the brain. However, the majority of studies on the neural basis of avian courtship displays focus on vocalizations and very little is known about how the brain produces and modulates non-vocal courtship displays. I will address this knowledge gap by examining the ruffed grouse (Bonasa umbellus), a species that does not vocalize in its courtship. Instead, male grouse produce a low frequency drumming display. Through a series of field experiments, my lab will determine how grouse generate the low frequency sound characteristic of this display and identify the neural circuitry required to produce the display. Mating systems also play a significant role in how the brain evolves. Our understanding of how mating system is related to brain anatomy and evolution is, however, based on two-species comparisons in which one species is asocial and polygamous whereas the other is social and monogamous. These comparisons are inherently confounded because it is unclear whether the differences are attributable to sociality or mating system. Determining whether brain region size or neurochemistry reflects mating systems or not therefore requires the analysis of species that vary in both sociality and mating system. My previous research showed that the social, polygamous Richardson's ground squirrel (Urocitellus richardsonii) has markedly different seasonal and sex differences in hippocampal anatomy than other polygamous rodents. This suggests that sociality and other behaviours might play a significant role in how the hippocampus evolves. Here, I propose to build upon this initial work and quantify the sex and seasonal differences in greater anatomical detail and test for differences in spatial abilities in both wild and lab-reared ground squirrels. Mating system is, however, also related to neurochemistry, especially the distribution of neuropeptide receptors. I will also test if there are significant sex differences in the distribution of oxytocin and vasopressin receptors in Richardson's ground squirrels. Finally, I will test whether sexual dimorphism in the hippocampus varies across mating systems by performing comparative tests across ground squirrels and grouse. Because sexual dimorphism in hippocampal anatomy is thought to reflect home range sizes and movement, I predict that asocial ground squirrels will have greater sexual dimorphism in the hippocampus than social species. Similarly, I expect that the polygamous ruffed grouse will have greater sexual dimorphism in the hippocampus than the monogamous ptarmigan (Lagopus spp.). Through this unique combination lab and fieldwork and studies within and across species, my research will greatly improve our understanding of brain-behaviour relationships and general principles of evolutionary neurobiology that will help to refine hypotheses about how the brain evolves.

不同脊椎动物的大脑在大小和形状上有很大差异，但这种解剖学差异是如何以及为什么存在的，在很大程度上是未知的。我的研究项目通过了解大脑和行为如何协同进化来解决神经科学中的这个基本问题。更具体地说，我测试进化理论的有效性，适用于大脑通过研究内和跨物种，并使用一系列的神经科学，动物行为和进化生物学技术。在这个资助周期中，我将重点关注与大脑进化有关的生殖行为的两个方面：求偶展示和交配系统。求偶是繁殖的重要组成部分，在鸟类中，不同求偶表现的进化与大脑的解剖学变化有关。然而，大多数关于鸟类求偶显示的神经基础的研究都集中在发声上，而对大脑如何产生和调节非发声求偶显示知之甚少。我将通过研究皱叶松鸡（Bonasa umbellus）来解决这个知识差距，这种松鸡在求爱时不会发声。相反，雄性松鸡会发出低频的鼓声。通过一系列的现场实验，我的实验室将确定松鸡如何产生这种显示器的低频声音特性，并确定产生这种显示器所需的神经回路。交配系统在大脑的进化中也起着重要的作用。然而，我们对交配系统与大脑解剖学和进化的关系的理解是基于两个物种的比较，其中一个物种是社会性和一夫多妻制，而另一个是社会性和一夫一妻制。这些比较本质上是混淆的，因为不清楚这些差异是归因于社会性还是交配系统。因此，确定大脑区域的大小或神经化学是否反映了交配系统，需要对社会性和交配系统都不同的物种进行分析。我以前的研究表明，社会，一夫多妻的理查森的地松鼠（Urocitellus richardsonii）有显着不同的季节和性别差异，海马解剖比其他一夫多妻的啮齿动物。这表明社交和其他行为可能在海马体的进化中起着重要作用。在这里，我建议建立在这个初步的工作和量化的性别和季节差异更详细的解剖和测试的空间能力在野生和实验室饲养的地松鼠的差异。然而，交配系统也与神经化学，特别是神经肽受体的分布有关。我还将测试是否有显着的性别差异，催产素和加压素受体的分布在理查森的地面松鼠。最后，我将通过对地松鼠和松鸡进行比较测试，来测试海马体中的性二态性是否在交配系统中有所不同。由于海马解剖学上的两性异形被认为反映了家域的大小和运动，我预测，与社会物种相比，非社会性地松鼠在海马中会有更大的两性异形。同样，我认为一夫多妻制的皱腿松鸡在海马中的性二态性比一夫一妻制的雷鸟（Lagopus spp.）更大。通过这种独特的组合实验室和实地考察以及物种内和跨物种的研究，我的研究将大大提高我们对大脑行为关系和进化神经生物学一般原理的理解，这将有助于完善关于大脑如何进化的假设。