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: 8513808
• 负责人: ALEJANDRO RAMIREZ
• 金额: $ 3.09万
• 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 2014-01-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8513808
• 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; Psychophysics; 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.

描述（由申请人提供）：了解大脑如何处理复杂信号是感觉神经科学的基本目标之一。这些研究需要人们能够将感觉神经元的反应与引起它们的复杂感觉刺激相关联。在触须初级体感系统（S1）中，这些研究传统上被证明具有挑战性，原因有两个：1）将时空复杂的刺激独立地传递到多个触须在技术上是困难的，以及2）S1中的放电率通常很低，以至于不可能获得构建准确的感受野估计所需的数据量。这个项目已经克服了这两个限制，通过开发一种新的多晶须刺激器系统，能够刺激一个更高的维度空间比以前探索。此外，我们已经开发了新的感受野估计方法，依赖于阈下信息，而不是尖峰。这些进步使我们能够在几分钟内收集到通过传统的细胞外记录需要几个小时才能收集的数据量。此外，我们的方法是能够检测到的非线性现象，没有检测到的经典使用的感受野分析依赖于尖峰。我们的研究将是第一个探讨躯体感觉皮层的皮质柱中时空复杂刺激处理的突触机制。这项研究将告诉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的多须刺激器系统，我们将研究L4如何整合复杂的刺激，这在亚阈值水平驱动响应多个胡须。我们开发了非线性分析方法来表明L4以非线性方式集成多须输入。这些非线性对于在复杂刺激期间克服L4中的环绕抑制可能是重要的。接下来，我们利用我们的多须刺激器系统来解决L2/3神经元的响应特性。具体来说，我们能够解决的理论，L2/3是使用稀疏编码策略来编码复杂的刺激信息。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，然后将刺激传递回同一神经元，从而使其激发。通过驱动L2/3中的尖峰响应，我们将能够确定L2/3是否采用稀疏编码机制，以及L2/3对哪些刺激特征敏感。最后，我们将表明，L5/6神经元可能是重要的编码结构特征的感觉环境。我们将使用我们新开发的感受野分析技术来探测S1深层神经元的时空复杂感受野。这些感受野将告诉我们深层神经元是否对提取结构特征很重要，这些结构特征由胡须之间的时间延迟编码。我们的研究将有助于推动该领域对皮层微电路如何处理复杂和自然信息的统一理解。

项目成果

Sensory experience restructures thalamocortical axons during adulthood.

• DOI: 10.1016/j.neuron.2012.03.022
• 发表时间: 2012-05-24
• 期刊: Neuron
• 影响因子: 16.2
• 作者: Oberlaender M;Ramirez A;Bruno RM
• 通讯作者: Bruno RM

Cell type-specific three-dimensional structure of thalamocortical circuits in a column of rat vibrissal cortex.

• DOI: 10.1093/cercor/bhr317
• 发表时间: 2012-10
• 期刊: Cerebral cortex (New York, N.Y. : 1991)
• 作者: Oberlaender M;de Kock CP;Bruno RM;Ramirez A;Meyer HS;Dercksen VJ;Helmstaedter M;Sakmann B
• 通讯作者: Sakmann B