Experience Dependent Neocortical Development

经验依赖性新皮质发育

• 批准号: 7078532
• 负责人: Daniel J. Simons
• 金额: $ 24.07万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7078532
• 关键词: axon; biological signal transduction; dendrites; developmental neurobiology; experience; glutamate transporter; histochemistry /cytochemistry; neocortex; neural conduction; neural information processing; neural transmission; neurons; somesthetic sensory cortex; synapses; touch; vibrissae; voltage /patch clamp

DESCRIPTION (provided by applicant): The long-term goal of our research is to understand how experience influences the organization and development of cortical microcircuits Of particular interest is how neonatal tactile experience influences whisker-related barrels in the rat somatosensory cortex. Our previous studies demonstrate that normal tactile experience is essential for the establishment of normal response properties of cortical barrel neurons. Trimming whiskers for the first few postnatal weeks leads to increased excitability of barrel neurons and to a robust and permanent enlargement of their receptive fields. These changes are not, however, accompanied by changes in the topographic pattern or overall morphology of barrels. Instead, available evidence indicates that these physiological abnormalities reflect alterations in local excitatory circuits within individual barrels.The proposed research plan will investigate in detail the development of cortical microcircuits and their alteration by abnormal tactile experience. The research is based on the premise that individual barrels are composed of modular units, and it is at the level of these microcircuits that neonatal experience exerts its influence. These microcircuits are now amenable to analysis using modern cellular-based anatomical and physiological techniques.Experiments are designed to investigate, in normal and whisker-trimmed rats, how cortical microcircuits become matched structurally and functionally to their afferent inputs. Specifically, we will examine in detail 1) the arborization pattern of individual thalamocortical axons, 2) the spatial pattern of locally recurrent intra-barrel connections, and 3) the strength of excitatory synaptic transmission onto individual barrel neurons.Results of the proposed research will provide insight into developmental mechanisms that organize local cortical circuits. By extending, to the somatosensory cortex, important findings from investigations of the visual system, the anticipated results will contribute directly to the identification of general principles of activity-dependent processes underlying cortical development. An understanding of these principles and the cellular mechanisms through which they operate is essential for the eventual diagnosis, treatment and prevention of developmental disorders affecting perception, cognition and other higher cortical functions

描述（由申请人提供）：我们研究的长期目标是了解经验如何影响皮层微电路的组织和发展。特别感兴趣的是新生儿触觉经验如何影响大鼠体感皮层中与胡须相关的桶。我们以前的研究表明，正常的触觉经验是必不可少的建立正常的反应特性的皮层桶神经元。在出生后的头几周修剪胡须会增加桶神经元的兴奋性，并使其感受野持久而稳固地扩大。然而，这些变化并不伴随着桶的地形格局或总体形态的变化。相反，现有的证据表明，这些生理异常反映了局部兴奋回路在个别barbns.The拟议的研究计划将详细调查皮层微电路的发展和异常触觉经验的改变。这项研究是基于这样一个前提，即每个桶都是由模块化单元组成的，新生儿的经验正是在这些微电路的水平上发挥其影响力。这些微回路现在可以用现代细胞解剖学和生理学技术进行分析，实验旨在研究正常和胡须修剪大鼠的皮层微回路如何在结构和功能上与其传入输入相匹配。具体而言，我们将详细研究1）单个丘脑皮层轴突的树枝状模式，2）局部复发的桶内连接的空间模式，3）兴奋性突触传递到单个桶神经元的强度。拟议的研究结果将提供深入了解组织局部皮层回路的发育机制。通过将视觉系统研究的重要发现延伸到躯体感觉皮层，预期的结果将直接有助于确定皮层发育的活动依赖性过程的一般原则。理解这些原理和它们运作的细胞机制对于最终诊断、治疗和预防影响知觉、认知和其他高级皮质功能的发育障碍是必不可少的

项目成果

Subbarrel patterns in somatosensory cortical barrels can emerge from local dynamic instabilities.

• DOI: 10.1371/journal.pcbi.1000537
• 发表时间: 2009-10
• 期刊: PLoS computational biology
• 影响因子: 4.3
• 作者: Ermentrout B;Simons DJ;Land PW
• 通讯作者: Land PW

Whisker trimming begun at birth or on postnatal day 12 affects excitatory and inhibitory receptive fields of layer IV barrel neurons.

出生时或出生后第 12 天开始的胡须修剪会影响第四层桶状神经元的兴奋性和抑制性感受野。

• DOI: 10.1152/jn.00569.2005
• 发表时间: 2005
• 期刊: Journal of neurophysiology.
• 作者: Shoykhet,Michael;Land,PeterW;Simons,DanielJ
• 通讯作者: Simons,DanielJ