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

软体动物的神经系统表现出的多样性超过了任何其他门，也许脊索动物除外。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对象，而那些定居的石鳖最多只能被描述为初级。然而，我们目前对软体动物的神经系统是如何发展的，以及这种多样性是如何通过进化产生的，知之甚少。此外，来自模式生物（如苍蝇、蠕虫和某些脊椎动物）的神经发育知识似乎不足以解决这一问题。该应用程序提出了两条研究路线，旨在更好地理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，并寻找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），但在这两个群体之外大部分未知。对软体动物的研究不仅能让我们了解这些动物的嗅觉是如何进化的，还能让我们深入了解我们自己的嗅觉。第二条线涉及对幼虫神经系统的研究，它在生命早期起着至关重要的作用，并为成年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，因此可以作为比较具有不同体型的动物的基础。我们的工作重点是识别和形态学细胞使用乙酰胆碱和组胺作为递质，然后研究它们在行为中的作用，使幼虫能够定位化学物质，光，电流和重力。这两条研究路线都将依赖于使用多种组合染色技术，再加上高分辨率显微镜和3D重建。软体动物是软体动物中种类最多、规模最大的门，从目前的模式物种中提供了一个重要而独特的视角。虽然主要是为了更好地了解我们周围生命的多样性，但这项工作也有助于理解幼虫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。

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.