Mechanical Signals and Trigeminal Ganglion Neuron Responses During Whisking

 描述(申请人提供)：大鼠三叉神经系统是神经科学领域的一个重要模型，用于分析感觉和运动信号之间的关系，以及大脑如何整合这些信息以实现感知。最近的研究探索了三叉神经节(VG)记录的神经信号与接触和非接触(自由空气)拨动时的运动学变量(即位置、速度和相位)之间的关系。虽然有一些证据表明VG响应与接触搅拌过程中的运动学变量之间存在相关性，但非接触搅拌过程中的关系远没有那么令人信服。这一建议的目的是寻找清醒的行为大鼠的VG反应与非接触搅拌过程中由振动挠度在胡须底部产生的力学变量(即力和力矩)之间的相关性。我们的假设是，VG神经元在非接触搅拌过程中的反应与晶须底部的力学变量最直接相关，这些变量是由晶须在自由空气中偏转的惯性特性产生的。另一种选择是，神经反应与胡须底部的几何变量最直接相关，但受随机性主导。验证这一假设将通过三个目标实现：在目标1中，我将通过实验将密度和阻尼量化为晶须弧长的函数，以正确估计振动的动态参数。对于目标2，我将使用目标1中生成的结果来构建晶须动力学的三维模型。为此，我还将通过动态搅拌模拟对3D模型的弹簧和阻尼系数进行实验验证。最后，在目标3中，我将使用在目标2中创建的3D动态模型来关联清醒状态下、表现为大鼠的三叉神经节神经元的反应与在非接触性偏转过程中在胡须底部产生的力学和几何变量。这项拟议工作的最终结果对于理解感觉信息的神经学编码具有重要意义，特别是在三叉神经系统内，并将提供一个3D动态模型，用于在未来的研究中模拟非接触式和接触式拨动，该研究将三叉神经通路上的神经信号与胡须底部的机械输出联系起来。

 DESCRIPTION (provided by applicant): The rat vibrissal-trigeminal system is an important model in the field of neuroscience for analyzing the relationship between sensory and motor signals and how the brain integrates this information to enable perception. Recent studies have explored the relationship between the neural signals recorded from the trigeminal ganglion (Vg) and kinematic variables (i.e., position, velocity, and phase) during both contact and non-contact (free-air) whisking. Although there is some evidence for correlation between the Vg responses and kinematic variables during contact whisking, the relationship during non-contact whisking is far less convincing. The objective of this proposal is to search for correlations between Vg responses in awake, behaving rats and mechanical variables (i.e., forces and moments) produced at the base of the whisker by vibrissal deflections during non-contact whisking. Our hypothesis is that the responses of Vg neurons during non-contact whisking are most directly correlated with mechanical variables at the whisker base generated by the inertial properties of the whisker deflecting in free-air. The alternative is that the neural responses are most directly correlated with geometric variables at the whisker base, but dominated by stochasticity. Testing this hypothesis will be achieved through three aims: In Aim 1, I will experimentally quantify density and damping as functions of whisker arc length to correctly estimate the dynamic parameters of vibrissae. For Aim 2, I will use the results generated in Aim 1 to construct a three-dimensional model of whisker dynamics. In this aim, I will also experimentally validate the spring and damping coefficients of the 3D model via dynamic whisking simulations. Finally in Aim 3, I will use the 3D dynamic model created in Aim 2 to correlate the responses of neurons in the trigeminal ganglion in awake, behaving rats with the mechanical and geometric variables produced at the base of the whisker during non-contact deflections. The final outcome of the proposed work has significance for understanding neurological coding of sensory information, especially within the trigeminal system, and will provide a 3D dynamic model for simulating both non-contact and contact whisking in future studies that relate neural signals along the trigeminal pathway to their mechanical output at the whisker base.