Coding properties of Vibrissal-Responsive Trigeminal Ganglion Neurons

触须响应三叉神经节神经元的编码特性

基本信息

批准号：
9091661
负责人：
Mitra J Hartmann
金额：
$ 32.11万
依托单位：
NORTHWESTERN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9091661
关键词：
Afferent Neurons Animals Area Behavior Behavior Control Brain Cells Characteristics Code Coffee Complex Data Development Dimensions Disease Equation Exploratory Behavior Frequencies Gatekeeping Genetic Geometry Glare Goals Head Health Hearing Investigation Laboratories Learning Length Light Location Mechanics Mechanoreceptors Modeling Motion Movement Neocortex Neurons Neurosciences Pathway interactions Patients Pattern Phase Physics Physiological Positioning Attribute Problem Solving Process Property Rattus Reaction Research Retinal Ganglion Cells Rodent Role Rotation Sensory Signal Transduction Staging Stimulus Stroke Structure of trigeminal ganglion Study models Surface System Testing Thalamic structure Time Touch sensation Trigeminal System Vibrissae Work awake barrel cortex base design experience ganglion cell grasp kinematics loved ones optogenetics predicting response receptor relating to nervous system research study response somatosensory sound spiral ganglion vibration

项目摘要

DESCRIPTION (provided by applicant): We see because retinal ganglion cells respond to light. We hear because spiral ganglion cells respond to sound. We feel because primary somatosensory neurons respond to "touch." But what is "touch?" Whereas light and sound can be characterized by physical parameters (amplitude, frequency, phase, and polarization), the mechanics of touch, and the manner in which primary sensory neurons encode the parameters of touch, are largely unquantified. This is a glaring gap within the entire field of somatosensation, and it occurs because mechanics are difficult to quantify. To close this gap we will use the rat vibrissal (whisker) system as a model to directly relate the responses of primary sensory neurons to the quantified mechanics of touch. Paralleling the increased use of rodents in genetic and optogenetic research, the rodent vibrissal array has become an increasingly important model for the study of touch and sensorimotor integration. In the past few years, our laboratory has made rapid progress in characterizing vibrissal mechanics, and we are now uniquely positioned to determine how 3D whisker deflections and vibrations are represented in the firing patterns of primary sensory neurons of the trigeminal ganglion (Vg) during natural whisking behavior. The central goal of our investigation is to predict the responses of Vg neurons during both contact and non-contact whisking by appropriately combining 3D dynamic and quasistatic models of mechanical signals. Our three aims move from the outside of the rat inwards, from whisker, to follicle, to Vg neurons. In Aim 1, we will develop models of mechanical coding by the whisker, quantifying the 3D mechanical signals at the vibrissal base during both contact and non-contact whisking. In Aim 2, these models will be used to predict responses of mechanoreceptors within the follicle and thus to identify classes of Vg neurons based on the mechanical transformation they perform. Finally, in Aim 3 we will quantify the responses of Vg neurons during natural whisking behavior in awake animals. Exploiting the cell classes identified in Aim 2, and consistent with the modeling of Aim1, we will test the hypothesis that Vg responses are more linearly correlated with mechanical signals during whisking than they are with the geometry and kinematics of whisking behavior. The proposed work will be the first to record from Vg neurons in awake behaving animals while fully characterizing the mechanical input during both contact and non-contact whisking. We aim to solve a large portion of the "coding problem" for the vibrissal-trigeminal system. Solving this problem will provide a better understanding of what a Vg spike "means" for more central stages of the trigeminal system, including sensory thalamus and barrel cortex.

描述（由申请人提供）：我们看到是因为视网膜神经节细胞对光做出反应。我们听到是因为螺旋神经节细胞对声音做出反应。我们感觉是因为初级体感神经元对“触摸”做出反应。可以通过物理参数（幅度、频率、相位和偏振）来表征，触摸的机制以及初级感觉神经元编码触摸参数的方式在很大程度上是未量化的。整个躯体感觉领域存在明显的差距，而这种差距的发生是因为力学难以量化，为了弥补这一差距，我们将使用大鼠触须（晶须）系统作为模型，将初级感觉神经元的反应与量化的力学直接联系起来。随着啮齿类动物在遗传和光遗传学研究中的使用不断增加，啮齿类动物振动阵列在过去几年中已成为研究触摸和感觉运动整合的越来越重要的模型。在表征振动力学方面取得了快速进展，我们现在处于独特的地位，可以确定在自然拂动行为期间如何在三叉神经节（Vg）的初级感觉神经元的放电模式中表示 3D 胡须偏转和振动，这是我们的中心目标。研究的目的是通过适当结合机械信号的 3D 动态和准静态模型来预测 Vg 神经元在接触和非接触搅拌过程中的反应，我们的三个目标是从大鼠的外部向内移动。从晶须到毛囊，再到 Vg 神经元在目标 1 中，我们将开发晶须的机械编码模型，量化接触和非接触晶须期间触须基部的 3D 机械信号。用于预测毛囊内机械感受器的反应，从而根据 Vg 神经元执行的机械转换来识别它们的类别。最后，在目标 3 中，我们将量化 Vg 神经元的反应。利用 Aim 2 中确定的细胞类别，并与 Aim1 的建模一致，我们将测试以下假设：Vg 响应与搅拌过程中的机械信号的线性相关性高于与几何形状和运动学的相关性。所提出的工作将是第一个从清醒行为动物的 Vg 神经元中记录，同时充分表征接触和非接触式搅拌过程中的机械输入。我们的目标是解决大部分“编码”问题。解决这个问题将有助于更好地理解 Vg 尖峰对于三叉神经系统的更中央阶段（包括感觉丘脑和桶状皮层）的“意义”。