form and function of the gastropod larval nervous system

世界上许多最丰富的生物严重依赖于幼虫阶段，而幼虫阶段的形态和功能却鲜为人知。海洋中充斥着这样的无脊椎动物幼虫，它们允许扩散，从而确保种群的补充、持续的遗传多样性和新地理区域的殖民。这种幼体对于野生重要的经济物种来说是必不可少的，在水产养殖中也面临着挑战。从基本生物学原理的角度来看，了解幼虫阶段对于解释后续成体计划的发展和世界所依赖的生物多样性的进化也是至关重要的。我们的实验室与世界上少数几个实验室一起，最近在描述最重要的海洋生物门之一--软体动物的幼虫的形态和功能方面取得了重大进展。在这项应用中，我们建议研究幼虫神经系统如何控制常见的潮间带蜗牛Ilyanassa的纤毛和肌肉，这些肌肉用于产生游泳和摄食行为。我们将首先使用已经证明在我们手中有用的技术(免疫细胞化学、行为药理学)来识别神经系统中的神经递质并确定它们的作用。然而，为了了解单个神经元的功能，我们需要使用电生理学和现代光学成像技术。这些研究将涉及使用微电极穿透单个幼虫神经元，这些神经元可以用生命染色或DIC光学技术进行可视化，并将允许研究细胞特性和突触连接。同时注射染料将显示详细的解剖结构。我们还将转向最先进的光学成像技术，这将使我们能够研究单个神经元和细胞群体的活动。这些研究将包括首次在细胞水平上对软体动物幼虫神经系统的详细分析，并为未来软体动物之间和门之间的比较提供基础。

Many of the world's most abundant organisms depend critically upon larval stages that are poorly understood in terms of their form and function. The seas are full of such invertebrate larvae, which permit dispersal and thus ensure replenishment of populations, continued genetic diversity and colonisation of novel geographic regions. Such larval forms are essential for economically important species in the wild and present challenges during aquaculture. From the perspective of fundamental biological principles, understanding larval stages is also essential for explaining the development of subsequent adult body plans and the evolution of the very biodiversity upon which the world relies. Our lab, together with only a handful of others worldwide, has recently made major inroads in describing the form and function of larvae of one of the most important phyla of marine organisms: the molluscs. In this application, we propose to examine how the larval nervous system controls the cilia and muscles used to generate swimming and feeding behaviours in the common intertidal snail, Ilyanassa. We will start by using techniques which have already proven useful in our hands (immunocytochemistry , behavioural pharmacology) to identify neurotransmitters in the nevous system and determine their roles. However, to understand the functions of individual neurons, we will need to use electrophysiology, coupled with modern optical imaging techniques. These studies will involve the use of microelectrodes to impale single larval neurons, which can be visualized with vital stains or DIC optics, and will permit the study of cellular characteristics and synaptic connections. Simultaneous dye injections will reveal detailed anatomy. We will also turn to state-of-the-art optical imaging techniques which will permit us to study activity of both single neurons and populations of cells. These studies will comprise the first detailed analyses of the larval nervous system of molluscs at the cellular level and provide a basis for future comparisons across the molluscs and between phyla.