Neuroethology of navigation in Tritonia

Tritonia 导航的神经行为学

• 批准号: RGPIN-2015-04957
• 负责人: Wyeth, Russell
• 金额: $ 1.75万
• 依托单位: St. Francis Xavier University
• 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=679877
• 关键词: Neuroethology; navigation; Tritonia

My overall goal is to understand how animals use multiple navigation strategies to move.  My students and I will tackle this problem by focusing on odour-based navigation in the sea slug Tritonia diomedea. Considerable effort has been spent understanding how animals respond to attractive odour plumes to find odour sources.  A variety of studies have shown that the slugs and other animals do no use odours alone for this process.  Instead, the presence of odours stimulate the animals to crawl upstream, following the flow to the odour source. Yet, in nature, flow directions frequently change. We know much less about the consequences of this flow variability on animal navigation. My first two objectives are to explore how the slugs cope with flow variability at two different levels: one level that should be tracked in order to reach the odour source, and another level that should probably be ignored for successful navigation. First, as bulk flow direction changes in a habitat, so too do odour plumes.   Animals must track these changes in the flow carrying the odour plume to find odour sources. My students and I will use field video recordings to explore how responsive Tritonia is to shifting flows of varying degrees. Second, inside an odour plume carried by unchanging bulk flow, water movement across the sea floor generates smaller scale variations in flow direction. This turbulence does not provide useful information for finding the odour source, and should be ignored.  The slugs show movements that suggest they may be adapted to cope with the turbulence, but there has been no experimental verification of this possibility.  Consequently, I will also test for how responsive the slugs are to finer flow variations, and thus gain insight into how the slugs may differentiate between changes in bulk flow direction versus changes from turbulent flow. My final objective is to lay a foundation for exploration of how the slugs' nervous system produces these behaviours. The experimental amenability and simpler nervous system of Tritonia allow experiments to test the roles of single neurons in cue detection and the subsequent control mechanisms of the slugs' crawling. I propose to study the structure and function of the sensory components of the nervous system, as well as test which neurons directly control turns stimulated by odours in flow. These two components serve as the input and output respectively for the circuit of neurons that controls navigation, and the results will guide future work studying how that circuit functions to produce the different navigational strategies. More generally, by comparing these results to those from across the animal kingdom, we can achieve a broader understanding of the neural mechanisms underlying navigation behaviour. Moreover, the methods used here are applicable to other areas of neuroscience, and my students will acquire valuable skills as they continue in academic or professional careers.

我的总体目标是了解动物如何使用多种导航策略来移动，我和我的学生将通过关注海蛞蝓基于气味的导航来解决这个问题。寻找气味来源。​各种研究表明，蛞蝓和其他动物在这个过程中并不单独使用气味。​相反，气味的存在会刺激动物爬行然而，在自然界中，我们对这种流动变化对动物导航的影响知之甚少。两个不同的级别：一个级别应该被跟踪以到达气味源，另一个级别可能应该被忽略以便成功导航。首先，随着栖息地中整体流动方向的变化，动物也必须跟踪气味羽流。这些变化我和我的学生将使用现场视频记录来探索 Tritonia 对不同程度的变化流的反应，在由不变的整体水流、跨海的水运动携带的气味羽流中。这种湍流不会为寻找气味源提供有用的信息，因此应忽略这些流段的运动，这表明它们可能适合应对湍流。但还没有对这种可能性进行实验验证，我还将测试段塞对更精细的流动变化的响应程度，从而深入了解段塞如何区分整体流动方向的变化与湍流方向的变化。我的最终目标是为探索蛞蝓的神经系统如何产生这些行为奠定基础。Tritonia 的实验适应性和更简单的神经系统允许实验测试单个神经元在线索检测和后续控制机制中的作用。我建议研究神经系统感觉成分的结构和功能，并测试哪些神经元直接控制流动中气味刺激的转向，这两个成分分别充当电路的输入和输出。更一般地说，通过将这些结果与整个动物界的结果进行比较，我们可以对神经机制有更广泛的了解。此外，所使用的方法。这些适用于神经科学的其他领域，我的学生在继续从事学术或职业生涯时将获得宝贵的技能。