Processing of complex stimuli in the primary sensory cortex.

初级感觉皮层复杂刺激的处理。

• 批准号: 8400337
• 负责人: ALEJANDRO RAMIREZ
• 金额: $ 4.14万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8400337
• 关键词: Action Potentials; Address; Afferent Neurons; Animals; Automobile Driving; Back; Behavior; Brain; Code; Complex; Computer-Assisted Image Analysis; Corpus striatum structure; Cortical Column; Data; Detection; Disease; Electrodes; Entropy; Environment; Epilepsy; Esthesia; Fire - disasters; Goals; Hearing; Histologic; Hour; Human; Individual; Knowledge; Location; Measures; Metals; Methods; Metric; Modeling; Neurons; Noise; Output; Parkinson Disease; Patients; Pattern; Physiological; Process; Property; Psychophysiology; Rattus; Rodent; Role; Sensory; Shapes; Signal Transduction; Somatosensory Cortex; Stimulus; Structure; Study models; Synapses; System; Techniques; Testing; Texture; Touch sensation; Vibrissae; Visual; Whole-Cell Recordings; awake; barrel cortex; cell type; experience; extracellular; information processing; novel; receptive field; relating to nervous system; research study; response; sensory cortex; sensory neuroscience; sensory stimulus; somatosensory; spatiotemporal; theories; tool; tumor; vocalization

DESCRIPTION (provided by applicant): Understanding how the brain processes complex signals is one of the fundamental goals of sensory neuroscience. These studies require one to be able to correlate the responses of sensory neurons to the complex sensory stimuli that elicited them. In the whisker primary somatosensory system (S1), these studies have traditionally proven challenging for two reasons: 1) Delivering spatiotemporally complex stimuli to multiple whiskers independently has been technically difficult, and 2) firing rates in S1 are often so low that it is not possible to acquire the amount of data needed to construct accurate receptive field estimates. This project has overcome these two constraints by developing a new multi-whisker stimulator system capable of stimulating a higher dimensional space than previously explored. Additionally, we have developed novel receptive field estimation methods that rely on subthreshold information rather than spikes. These advances allow us to collect in minutes the amount of data that would have taken hours to collect through traditional extra-cellular recordings. Furthermore, our method is capable of detecting nonlinear phenomena that are not detected by classically used receptive field analysis relying on spikes. Ours will be the first study that investigates the synaptic mechanisms underlying the processing of spatiotemporally complex stimuli in a cortical column of somatosensory cortex. This study will inform us how sensory cortices process complex stimulus information, as well as how the brain detects complex structural features in the sensory world. Through the use of whole- cell recordings and our new multi-whisker stimulator system, we will investigate how L4 integrates complex stimuli, which at the subthreshold level drives responses up to multiple whiskers away. We develop nonlinear analysis methods to show that L4 integrates multi-whisker inputs in a nonlinear fashion. These nonlinearities may be important for overcoming surround suppression in L4 during complex stimuli. Next we take advantage of our multi-whisker stimulator system to address response properties of neurons in L2/3. Specifically we are able to address the theory that L2/3 is using a sparse coding strategy to encode complex stimulus information. Through the use of a maximum noise entropy model, we are able to calculate the optimal stimulus for a L2/3 neuron online, and then deliver the stimulus back to the same neuron, thus making it fire. By driving spiking responses in L2/3 we will be able to determine whether L2/3 is employing a sparse coding regime, as well as what stimulus features L2/3 is sensitive to. Lastly, we will show that L5/6 neurons may be important for encoding structural features in the sensory environment. We will use our newly developed receptive field analysis techniques to probe the spatiotemporally complex receptive fields of deep layer neurons in S1. These receptive fields will inform us whether deeper layer neurons may be important for extracting structural features, encoded by temporal delays between whiskers. Our study will help move the field toward a unified understanding of how cortical microcircuits process complex and naturalistic information. PUBLIC HEALTH RELEVANCE: Understanding the functional response properties of neurons throughout the depths of a cortical column will allow us to probe the contributions of different layers of the cortex in behavior as well as in disease. In particular, deep layer neurons involved in striatal and callosal circuits have been implicated in epilepsy and Parkinson's and understanding what drives these neurons will provide an invaluable tool for understanding the role of these circuits in disease. This project illuminates the functional response properties of different neurons throughout the cortical layers during complex sensory stimulation, in the specific case of the primary somatosensory cortex.

描述（由申请人提供）：了解大脑处理复杂信号如何是感觉神经科学的基本目标之一。这些研究要求人们能够将感觉神经元与引起它们引起的复杂感觉刺激相关联。在晶须初级体感系统（S1）中，这些研究在传统上被证明具有挑战性，有两个原因：1）在技术上很困难，在技术上独立地将时空复杂的刺激传递到多个晶须上非常困难，2）S1中的发射速率通常很低，以至于无法获得准确的数据量所需的数据量，以构建准确的数据接收现场估计。该项目通过开发一种能够刺激比以前探索的更高的尺寸空间的新的多晶刺激器系统来克服这两个约束。此外，我们开发了依赖亚阈值信息而不是尖峰的新型接受场估计方法。这些进步使我们能够在几分钟内收集通过传统细胞外记录需要花费数小时的数据量。此外，我们的方法能够检测非线性现象，这些现象未通过依靠尖峰的经典接受场分析检测到。我们的将是第一项研究，该研究研究了体感皮质的皮质柱中时空复杂刺激处理的基础的突触机制。这项研究将告知我们感觉皮层如何处理复杂的刺激信息，以及大脑如何检测感觉世界中的复杂结构特征。通过使用全细胞记录和我们的新多晶刺激器系统，我们将研究L4如何整合复杂的刺激，在子阈值级别上，该刺激将响应驱动到多个晶须。我们开发了非线性分析方法，以表明L4以非线性方式整合了多晶须输入。这些非线性对于在复杂刺激过程中克服L4的环绕抑制可能很重要。接下来，我们利用多轮刺激器系统来解决L2/3中神经元的响应特性。具体而言，我们能够解决L2/3使用稀疏编码策略来编码复杂刺激信息的理论。通过使用最大噪声熵模型，我们能够在线计算L2/3神经元的最佳刺激，然后将刺激恢复回相同的神经元，从而使其发射。通过在L2/3中驱动尖峰响应，我们将能够确定L2/3是否采用稀疏编码状态以及刺激功能L2/3对L2/3的敏感。最后，我们将证明L5/6神经元对于在感觉环境中编码结构特征可能很重要。我们将使用新开发的接受场分析技术来探测S1中深层神经元的时空复杂的接收场。这些接受场将告知我们更深的层神经元对于提取结构特征是否很重要，该特征由晶须之间的时间延迟编码。我们的研究将有助于将领域迈向统一的了解皮质微电路如何处理复杂和自然主义信息。 公共卫生相关性：了解整个皮质柱深处神经元的功能反应特性将使我们能够探究皮质不同层在行为和疾病中的贡献。特别是，参与纹状体和callosal回路的深层神经元与癫痫和帕金森氏症有关，并了解这些神经元的驱动因素将为了解这些电路在疾病中的作用提供宝贵的工具。在主要体感皮质的特定情况下，该项目在整个皮质刺激过程中阐明了整个皮质层的不同神经元的功能响应特性。