Neural Mechanisms underlying Evolvability of Behavior

该项目研究影响行为进化的神经回路特征的基本问题。正在研究的物种是裸鳃海蛞蝓，它们具有高度可接近的神经系统，可以进行在其他类型动物中不可行的实验。裸鳃类动物的大脑仅包含约10，000个神经细胞（神经元），其中许多可以在同一物种的动物之间单独识别。此外，神经元通常可以在不同物种中识别。电活动可以从多个神经元记录，以揭示神经回路。这些回路的连通性可以在不同物种之间进行比较。该研究小组发现，尽管这些物种具有相同的神经元组，但它们的连接方式不同，即使这些物种产生相似的行为。该项目的一个目标是人工重新连接一个物种的神经元，以产生另一个物种的神经回路，并创建同样的数学模型。这将确定将一个物种的行为转换为另一个物种的行为是多么容易。它还有助于通过跨物种比较而不是专注于单个物种来理解产生行为的基本规则。该项目通过社交媒体向世界各地的潜水员征求对裸鳃亚目动物行为的观察，从而吸引公众。它还通过研究管道为代表性不足的学生提供重要的研究机会，并为科学界创造资源，以帮助识别神经元和绘制电路。本计画探讨影响裸鳃类动物游泳行为演化的神经回路特徴。该项目使用各种技术来实现其目标。首先，转录组学是用来解决裸鳃亚目的胚胎发育，并允许胚胎发育假说进行测试。大脑转录组进一步帮助发现识别神经元的分子标记，这在不游泳的物种中尤其需要。 电生理学技术用于搜索“潜在”电路，即可能存在于非游泳者中并可能由微小变化激活的连接。这些变化将使用动态钳技术注射人工突触和膜电导，并通过5-羟色胺受体的异位表达来应用。最后，数学模拟被用来研究不同的电路架构的后果和他们的鲁棒性的节奏活动。

This project examines fundamental questions about the features of neural circuits that affect the evolution of behavior. The species being examined are nudibranch sea slugs, which have highly accessible nervous systems that allow experiments to be conducted that are not feasible in other types of animals. The brains of nudibranchs contain only about 10,000 nerve cells (neurons), many of which can be individually identified from animal to animal within a species. Furthermore, neurons can often be identified across different species. Electrical activity can be recorded from multiple neurons to reveal neural circuitry. The connectivity of those circuits can be compared across species. This research team found that although the species have the same sets of neurons, they are wired up differently, even when the species produce similar behaviors. One goal of the project is to artificially rewire the neurons in one species to produce the neural circuit of another species and to create mathematical models that do the same. This will establish how easy it is to convert the behavior of one species into that of another. It also contributes to understanding the basic rules for generating behavior by comparing across species instead of focusing on a single species. The project engages the public by soliciting observations of nudibranch behavior from divers around the world through social media. It also provides important research opportunities to under-represented students through a research pipeline and creates resources that will be available to the scientific community to aid in identifying neurons and mapping out circuits.Evolvability reflects the ability to evolve. This project examines the features of neural circuits that affect the evolvability of swimming behaviors in nudibranchs. The project uses a variety of techniques to achieve its goals. First, transcriptomics is used to resolve the phylogeny of the Nudibranchia and allow phylogenic hypotheses to be tested. The brain transcriptomes further aid in the discovery of molecular markers for identified neurons, which are needed particularly in species that do not swim. Electrophysiological techniques are used to search for "latent" circuitry, that is, connectivity that might be present in non-swimmers and potentially activated by small changes. These changes will be applied using the dynamic clamp technique to inject artificial synaptic and membrane conductances and through ectopic expression of serotonin receptors. Finally, mathematical simulations are used to examine the consequences of different circuit architectures and their robustness for rhythmic activity.