Flow Sensing in the Lateral Line System of Zebrafish Larvae

鱼类利用感知水中运动的能力来协调各种各样的行为，如捕获猎物、成群结队和产卵。这种感觉是由侧线系统促进的，侧线系统是身体表面的一系列受体，被称为神经细胞。在各种鱼类体内和鱼类之间，神经鞘的形状和大小各不相同。然而，目前还不清楚这种变化是如何影响鱼类探测水流的能力的。这项研究的目的是为神经鞘的微观力学建立一个模型，该模型将描述神经鞘形式的差异如何影响它们的敏感性。这一目标将通过分三个阶段组织的研究来实现。在第一阶段，实验将测量斑马鱼（Danio rerio）幼虫个体神经鞘的物质特性。特别是，神经杆的刚度将通过记录这些结构在加载细玻璃线时的弯曲来测量。这些测量结果将被纳入将在项目第二阶段开发的计算模型。该模型将考虑刺激的流体动力学、神经杆的结构动力学以及它们之间的力学相互作用，以预测神经杆如何响应流体流动而偏转。该项目的第三阶段将测试该模型，通过测量神经杆的偏转和神经生物学信号来响应宽频率范围内的振荡流。一旦该模型通过这些实验得到验证，它将为解释神经突的大小和形状的差异如何影响侧线系统的功能提供基础。这将允许考虑在发展和进化转变过程中的功能变化。这项工作将涉及学生在综合和跨学科领域的培训，将计算方法与侧线功能的生理评估相结合。

Fish use an ability to sense water motion to coordinate behaviors as varied as prey capture, schooling, and spawning. This sense is facilitated by the lateral line system, which is an array of receptors, known as neuromasts, on the surface of the body. Neuromasts appear in a wide variety of shapes and sizes within and among species of fish. However, it is unclear how this variation affects the ability of fish to detect water flow. The aim of the proposed research is to develop a model for the micromechanics of neuromasts that will describe how differences in the form of neuromasts affect their sensitivity. This aim will be achieved by research organized in three stages. In the first stage, experiments will measure material properties of individual neuromasts in the larvae of zebrafish (Danio rerio). In particular, the stiffness of neuromasts will be measured by recording the bending of these structures when loaded with a fine thread of glass. These measurements will be incorporated into a computational model to be developed in the second stage of the project. This model will consider the hydrodynamics of a stimulus, the structural dynamics of the neuromast, and their mechanical interactions in order to predict how a neuromast deflects in response to fluid flow. The third stage of this project will test this model by measuring the deflections and neurobiological signals of neuromasts in response to oscillatory flow over a wide range of frequencies. Once the model has been verified by these experiments, it will provide a basis for interpreting how differences in the size and shape of neuromasts influence the function of the lateral line system. This will allow for consideration of functional changes over the course of developmental and evolutionary transformation. The work will involve student training in an integrative and interdisciplinary area that combines computational approaches with physiological assessment of lateral line function.