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）：拟议的研究的目的是了解晶须的触觉体验如何修饰皮质桶周围隔膜中神经元的接受场（RF），以及隔隔神经元在感觉处理和皮质可变性中的作用。从解剖学上讲，第四层桶神经元水平地将枪管周围的隔片射入，并以帽子状图案垂直到枪管上方的枪管上方，以盖子状图案与每个桶上的帽子样图案重叠。与由特定的丘脑VPM输入主导的桶相反，间隔神经元是丘脑较少输入的皮质靶标，而对侧皮质的连续输入量较少。当几乎同时刺激两个晶须时，隔中间的一些细胞显示出（促进）反应。如果晶须刺激之间的延迟为20-50毫秒，则对枪管细胞中对第二晶须的反应被抑制，但在间隔细胞中与其位置有关。我们建议SEPTA是专门的区域，用于修改对几种颤音产生的输入的皮质反应。我们的主要假设是，间隔区域的地形提供了分布的细胞基质，其中比较了晶须输入的强度，并通过使用依赖性的，皮质内连接可塑性进行了修改。我们提出，间隔细胞作为感官信息调节剂的作用，因为它们会整合几个桶的活性，并相互反馈以修饰枪管RF。我们将测试一个观念，即，使用我们开发的可塑性测试（称为“晶须配对可塑性”）对枪管细胞反应的经验驱动的修饰有很大贡献。具体而言，我们希望定义晶须经验在确定成年分子细胞可塑性方面的作用，以显示如何在发育中调节使用依赖性可塑性。对中间细胞的这些特征的分析将提供有关枪管场皮层中感觉处理的重要新信息。结果将更好地理解感觉活动如何改变一生的皮质神经元的RF，实验将通过不充分的早期感觉体验（感觉剥夺）来指定在间隔神经元中产生的综合缺陷。