PLASTICITY OF BARREL FIELD INTRACORTICAL CIRCUITRY

桶状场皮质内回路的可塑性

• 批准号: 6747616
• 负责人: Ford Francis Ebner
• 金额: $ 28.69万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-09-25 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6747616
• 关键词: afferent nerve; brain electrical activity; developmental neurobiology; early experience; laboratory rat; neural information processing; neural plasticity; neuroanatomy; sensory cortex; sensory deprivation; sensory feedback; single cell analysis; touch; vibrissae

DESCRIPTION (provided by applicant): The goal of the proposed research is to understand how tactile experience with the whiskers modifies the receptive field (RF) of neurons in the septa around cortical barrels, and what role septal neurons play in sensory processing and cortical plasticity. Anatomically, layer IV barrel neurons project horizontally into the septa surrounding the barrels and vertically above the barrel to layers II+III in a cap-like pattern that overlaps around each barrel. In contrast to barrels, which are dominated by specific thalamic VPM inputs, septal neurons are the cortical target of less dense inputs from the thalamus and commissural inputs from the contralateral cortex. When two whiskers are stimulated nearly simultaneously, some cells in the septum show increased (facilitated) responses. If there is a delay of 20-50 ms between whisker stimuli, the response to the second whisker is inhibited in barrel cells, but not studied in septal cells in relation to their location. We propose that the septa are specialized regions for modifying cortical responses to inputs that are generated by several vibrissa. Our main hypothesis is that the topography in the septal regions provides a distributed cell matrix in which the strength of whisker inputs is compared and modified through use-dependent, intracortical connection plasticity. We propose that septal cells operate as sensory information modulators in that they integrate the activity of several barrels and feed back reciprocally to modify barrel RF's. We will test the notion that septal cells contribute strongly to experience-driven modifications of barrel cell responses using a test for plasticity that we developed, called "whisker pairing plasticity". Specifically, we wish to define the role of whisker experience in determining adult septal cell plasticity to show how use-dependent plasticity is developmentally regulated. Analysis of these characteristics of the septal cells will provide significant new information about sensory processing in the barrel field cortex. The results will generate a better understanding of how sensory activity modifies the RF of cortical neurons throughout life, and the experiments will specify integrative deficits that are produced in septal neurons by inadequate early sensory experience (sensory deprivation).

描述（由申请人提供）：拟议研究的目标是了解胡须的触觉体验如何改变皮质桶周围隔中神经元的感受野（RF），以及隔神经元在感觉处理和皮质可塑性中起什么作用。在解剖学上，第IV层桶神经元水平地投射到围绕桶的隔膜中，并且垂直地在桶上方投射到第II+III层，以帽状图案重叠在每个桶周围。与桶，这是由特定的丘脑VPM输入为主，隔神经元是皮质的目标，从丘脑和连合输入从对侧皮质的密度较低的输入。当两个触须几乎同时受到刺激时，隔膜中的一些细胞表现出增加的（易化的）反应。如果在触须刺激之间有20-50 ms的延迟，则在桶细胞中对第二根触须的反应被抑制，但在与其位置相关的隔细胞中没有研究。我们建议，隔是专门的区域，用于修改皮质的反应，由几个触须产生的输入。我们的主要假设是，在隔区的地形提供了一个分布式的细胞矩阵中的晶须输入的强度进行比较和修改，通过使用依赖性，皮质内连接可塑性。我们建议，隔细胞作为感觉信息调制器，因为它们整合了几个桶的活动和反馈信号，以修改桶RF的。我们将测试的概念，隔细胞有助于强烈的经验驱动的桶细胞反应的修改，使用我们开发的可塑性测试，称为“晶须配对可塑性”。具体来说，我们希望定义的作用，胡须的经验，在确定成人隔细胞的可塑性，以显示如何使用依赖的可塑性发育调节。这些特征的隔细胞的分析将提供重要的桶场皮层的感觉处理的新信息。这些结果将更好地理解感觉活动如何在整个生命过程中改变皮层神经元的RF，并且实验将指定由早期感觉经验不足（感觉剥夺）在隔神经元中产生的整合缺陷。