DOCTORAL DISSERTATION: Evolution of neural circuits underlying species-specific swimming behaviors in opisthobranch molluscs

了解导致物种行为不同的神经机制一直是生物学中一个难以捉摸的目标。 该项目是博士论文的一部分，使用海蛞蝓（后鳃类软体动物）的神经系统，通过比较游泳行为背后的神经回路来解决这个问题。 海蛞蝓有大的神经元和简单的神经系统，使研究人员能够绘制出同样简单的行为背后的神经回路。 有些海蛞蝓通过上下弯曲身体来游泳。其他物种要么不游泳，要么以其他方式游泳。神经回路的基础上，上下游泳已确定在两个物种：Tritonia diomedea和Pleurobranchaea californica。 这两个物种游泳的神经回路和相互作用非常相似，尽管这些动物并不密切相关。 有证据表明，游泳的能力是使用相同（或同源）的神经元独立进化的。 这导致预测，以这种方式游泳的其他物种也会使用相同的神经元和神经相互作用来产生行为。 为了验证这一有趣的预测，将研究第三种上下运动的海蛞蝓。 目前唯一的物种分布在澳大利亚。 电生理学，药理学和组织学方法将由学生研究澳大利亚物种，以确定它是否也使用相同的神经元和神经机制。 这个项目的结果将有助于我们理解允许行为进化的神经机制。 一个积极的结果将表明，行为可以预测独立进化行为的动物的神经回路。 一个否定的结果仍然是有趣的，因为它表明类似的行为可以由不同的机制产生。 首先，这将是一个培训机会，为学生，将大大提高他的论文项目。 这项工作还将与国际同行建立新的伙伴关系。 该项目的结果将以研究论文的形式广泛传播，也将作为对NeuronBank.org的贡献，这是一个跟踪识别神经元和突触连接的项目。

Understanding the neural mechanisms that cause species to behave differently has been an elusive goal in biology. This project, which is part of a doctoral dissertation, uses the nervous systems of sea slugs (opithobranch molluscs) to address this issue by comparing neural circuits underlying swimming behavior. Sea slugs have large neurons and simple nervous systems, allowing researchers to map out neural circuitry underlying equally simple behaviors. Some sea slug species swim by flexing their bodies up and down. Other species either do not swim or swim by other means. The neural circuitry underlying up and down swimming has been determined in two species: Tritonia diomedea and Pleurobranchaea californica. The neural circuits and interactions underlying swimming in these two species are remarkably similar even though these animals are not closely related. There is evidence to suggest the ability to swim evolved independently using the same (or homologous) neurons. This leads to the prediction that other species that swim in this manner would also use the same neurons and neural interactions to produce the behavior. To test this intriguing prediction, a third species of sea slug that swims with up and down movements will be be studied. The only readily available species are found in Australia. Electrophysiological, pharmacological, and histological approaches will be employed by the student to study the Australian species to determine if it also uses the same neurons and neural mechanisms. The results of this project will contribute to our understanding of the neural mechanisms that allowed behavior to evolve. A positive result would show that behavior could predict neural circuitry in animals that independently evolved the behavior. A negative result would still be interesting because it would show that similar behaviors can be produced by different mechanisms.There are several broader impacts of this project. The first is that it will be a training opportunity for the student that will greatly enhance his dissertation project. The work will also establish a new partnership with colleagues internationally. The results of this project will be disseminated broadly both in the form of research papers, but also as contributions to NeuronBank.org, a project that tracks identified neurons and synaptic connections.