Form and function of the olfactory and larval nervous systems in molluscs

软体动物的神经系统表现出超过任何其他门的多样性，也许除了脊索动物。像章鱼这样的头足类动物的大脑和行为是亚里士多德着迷的主题，而久坐不动的石鳖的大脑和行为充其量只能被描述为初级的。然而，我们目前对软体动物神经系统是如何发育的，或者这种多样性是如何通过进化产生的知之甚少。此外，来自果蝇、蠕虫和某些脊椎动物等模式生物的神经发育知识似乎不足以解决这个问题。这项申请提出了两条研究路线，旨在更好地了解软体动物内部的神经进化和发育。第一行将研究嗅觉系统，寻找在节肢动物和脊椎动物中描述的感觉处理的基本单位(肾小球)，但在这两个组之外基本上不为人所知。对软体动物的研究不仅将让我们了解这些动物的嗅觉是如何进化的，还可能为我们提供对我们自己的嗅觉的洞察。第二行涉及对幼虫神经系统的研究，幼虫神经系统在早期生命中起着关键作用，并为成人神经系统的构建提供了一个支架。众所周知，软体动物的幼虫神经系统与整个动物界的幼虫神经系统有相似之处，因此可以作为比较其他不同身体形态的动物的基础。我们的工作集中在使用乙酰胆碱和组胺作为传递器的细胞的鉴定和形态上，然后检查它们在允许幼虫适应化学物质、光、电流和重力的行为中的作用。这两条研究路线都将取决于多种组合染色技术的使用，以及高分辨率显微镜和3D重建。作为软体动物中种类最多也是最大的门，软体动物从目前的模式物种中提供了一个重要而独特的视角。虽然这项工作主要是为了更好地了解我们周围生命的多样性，但这项工作也对理解幼体和成年软体动物是我们海洋生态系统的主要组成部分，甚至是水产养殖的珍贵食物也有影响。

The nervous systems of molluscs show a diversity which surpasses any other phylum, except perhaps the chordates. The brains and behaviours of cephalopods like the octopus were subjects of fascination for Aristotle, while those of sedentary chitons can be described only as rudimentary at best. And yet, we currently know very little about how the molluscan nervous system develops or how such diversity is generated through evolution. Moreover, knowledge of neural development derived from model organisms such as flies, worms and certain vertebrates appears inadequate to resolve this issue. This application proposes two lines of research aim at better understanding neural evolution and development within the molluscs. The first line will investigate the olfactory system and look for the basic units of sensory processing (glomeruli) as described in arthropods and vertebrates but largely unknown outside these two groups. Work on molluscs will not only inform us about how olfaction may have evolved in these animals but may provide insights into our own sense of smell. The second line involves investigation of the larval nervous system, which plays a critical role in early life and provides a scaffold on which the adult nervous system is built. The larval nervous system of molluscs is known to share similarities with larval nervous systems from across the animal kingdom and thus serves as a basis for comparison of animals with otherwise diverse body forms. Our work focuses on identification and morphology of cells which use acetylcholine and histamine as transmitters, and then examines their roles in behaviours that allow larvae to orient to chemicals, light, currents and gravity. Both lines of research will depend upon the use of multiple, combinational staining techniques coupled with high resolution microscopy and 3D reconstruction. As both the most varied and also the largest phylum in the Lophotrochozoa, the molluscs offer an important and unique perspective from current model species. While aimed largely at a better understanding of the diversity of life around us, the work also has implications for understanding larval and adult molluscs as major components of our ocean ecosystems and even as prized foods from aquaculture.