Collaborative Research: Origin and Evolutionary Divergence of the Pancrustacean Brain

在生命的早期历史中，大脑什么时候第一次出现仍然是未知的。在进化过程中，结构独特的主要大脑部分是如何发生变化的，人们对此也知之甚少。这些知识差距部分是由于大脑化石很罕见，很难研究。该项目的特点是来自三个合作实验室的科学家将汇集他们的资源，以确定一组介导学习和记忆的无脊椎动物大脑中心。将在现代昆虫和甲壳类物种中建立这些区域之间的结构和功能相似性和差异。这项研究要回答的主要问题是，这些大脑中心是否由于大脑而具有共同的遗传和计算属性？这可能是因为，大脑的基本组织是由一个共同祖先的后代继承的;或者，因为在不同的无脊椎动物群体中独立出现的大脑不能执行某些功能，除非赋予它们相同功能的大脑区域也独立出现。这些问题将通过精确测量无脊椎动物的大脑结构并将其基本排列与现代同行进行比较来回答。这项研究的更广泛影响将是确定在今天活着的脊椎动物（包括人类）中发现的学习和记忆大脑中心的无脊椎动物代理。识别这些代理将告诉我们大脑是如何进化的，并将有助于更广泛地理解记忆中心是如何组织的。这些结果将影响神经网络和人工智能的理论和研究，同时，进行这项研究的科学家将开发新的策略，用于识别各种物种大脑结构的谱系对应。这项研究分析的大脑将以3D数字重建，并上传到一个开源数据库，用于教育和研究目的。该研究还将为来自不同背景的学生提供先进的神经科学结构分析和基因组学培训。昆虫蘑菇体的神经元组织和电路特性以及它们在学习和记忆方面的功能特性是众所周知的。虽然在节肢动物中存在蘑菇体样中心，但尚不清楚这些中心在表型或基因型上是否与昆虫中的中心相对应。计划中的研究将在广泛的物种中识别蘑菇体样中心，分析它们的离散神经排列，电路组织和分子属性。这些比较将确定节肢动物门内外的物种，在这些结构中具有功能和形态的对应关系。转录组学将解决表型对应的中心是否具有共同的基因组属性，以及是否存在定义节肢动物蘑菇体的独特遗传网络，或者这些网络是否在不同的节肢动物群体中区分蘑菇体，例如昆虫和甲壳类动物。这些中心在广泛的系统谱系中广泛的表型和基因型同源性的鉴定表明这些学习和记忆中心的古老起源。同样有趣的是，研究结果表明，学习和记忆中心的趋同进化跨越taxa.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

It is still unknown when brains first appeared during the early history of life. The ways in which major brain parts that are structurally distinctive have changed over evolutionary time are also poorly understood. These knowledge gaps are partly due to the fact that fossil brains are rare and have been difficult to study. This project features scientists from three collaborating laboratories who will pool their resources to identify a set of invertebrate brain centers that mediate learning and memory. Structural and functional similarities and differences among these areas will be established across modern insect and crustacean species. The major question this research is answering is whether these brain centers share common genetic and computational attributes due to the brain?s fundamental organization being inherited by the descendants from a common ancestor; or, because brains that have arisen independently in different invertebrate groups are not able to perform certain functions unless brain areas that give them these same abilities have also arisen independently. These questions will be answered by precisely measuring the brain structures in fossilized invertebrate animals and comparing their basic arrangements with modern counterparts. The broader impact of this research will be to identify invertebrate proxies of the learning-and-memory brain centers found in vertebrate animals alive today, including humans. Identification of such proxies will inform us about how brains have evolved, and will contribute to a broader understanding of how memory centers are organized. The results will impact theories of, and research on, neural networks and artificial intelligence, and at the same time the scientists carrying out this research will develop novel strategies for identifying genealogical correspondence of brain structures across a very broad range of species. Brains analyzed for this research will be digitally reconstructed in 3D and uploaded to an open-source database for education and research purposes. The research will also provide advanced neuroscience structural analysis and genomics training to students from diverse backgrounds.The neuronal organization and circuit properties of insect mushroom bodies are well known, as are their functional properties for learning and memory. While the existence of mushroom-body-like centers exist across arthropods, it is not known whether these phenotypically or genotypically correspond to the centers in insects. The planned research will identify mushroom body-like centers across a broad range of species, analyze their discrete neural arrangements, circuit organization, and molecular attributes. These comparisons will identify the species within and outside Arthropoda that possess functional and morphological correspondences in these structures. Transcriptomics will address whether phenotypically-corresponding centers share common genomic attributes, and whether there are unique genetic networks that define arthropod mushroom bodies or whether these networks differentiate mushroom bodies in different groups of arthropods such as in insects and crustaceans. The identification of broad phenotypic and genotypic homology of these centers across a broad phyletic spectrum would suggest an ancient origin of these learning and memory centers. Equally intriguing would be results suggesting convergent evolution of learning and memory centers across taxa.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.