RECEPTIVE FIELDS OF LAYER IV (BARREL FIELD) NEURONS

第四层（桶状场）神经元的感受野

• 批准号: 2902688
• 负责人: Ford Francis Ebner
• 金额: $ 24.74万
• 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 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2902688
• 关键词: acetylcholine; behavior therapy; brain electrical activity; brain mapping; controlled environment; developmental neurobiology; early experience; histology; laboratory rat; microscopy; nervous system disorder chemotherapy; neural information processing; neural plasticity; neuroanatomy; neurotransmitter transport; nonhuman therapy evaluation; norepinephrine; sensory cortex; sensory deprivation; sensory feedback; single cell analysis; synapses; vibrissae

Neurons in somatic sensory cortex receive sensory information from the periphery throughout postnatal life. The central hypothesis for the proposed studies is that simple positive biases in the level of ongoing activity from selected whiskers is enough to potentiate their targeted synapses in cortex through glutamate receptor mechansisms. The studies will be carried out in the rat whisker to barrel field cortex pathway because the discrete, non-overlapping receptors in each whisker follide maintain a dear topography to and induding layer Iv of barrel field cortex. In addition, we have demonstrated that the receptive fields of neurons in adult rat barrel field cortex are modified by simply trimming some, but not all, of the whiskers for periods as short as 1 day or up to 30 days. Trimming all but two adjacent whiskers significantly increased the response of cortical neurons to spared whiskers and dramatically diminished the response to cut whiskers. The changes induced by whisker pairing were multifaceted and depend upon cell location in the barrel field cortex, the barrel's relationship to each whisker in the receptive field and how long they were trimmed or spared. Four specific aims are identified to analyze the circuits and mechanisms that support these plastic responses in adult rat cortex: Aim #1 is to compare the rate of change of synapses in each cortical layer induced by whisker pairing. Preliminary results show that supragranular neurons change before cells in any other layer. Two specific sub-goals are to test whether whisker pairing plasticity in the deeper layers requires prior changes in the superficial layers of cortex and whether the plasticity depends on glutamate receptor mechanisms. Aim #2 is to compare the limits of response enhancement that can be generated in the VPM thalamocortical fiber synapses before and after whisker pairing. Aim #3 is to analyze the role of extraIemniscal sensory modulators to barrel field cortex in the spread of activity between non-adjacent barrels when induced by whisker pairing. We will trim all but two non-adjacent whiskers to determine the effect of SII and POm lesions on the distance-limit for modifying connections between cortical barrels of the two intact whiskers. Aim #4 is to show the effect of depletion of non-sensory neuromodulators in cortex on whisker pairing plasticity.

躯体感觉皮质中的神经元从 在出生后的整个生命中都处于边缘状态。这一理论的核心假设是 建议的研究是，在正在进行的水平上存在简单的积极偏见 从选定的胡须中提取的活性足以增强它们的靶向 谷氨酸受体机制在大脑皮层的突触。这些研究 将在大鼠胡须到桶状野皮质的通路中进行 因为每个胡须中的离散的、不重叠的受体 保持良好的地形，包括第四层的桶状油田 大脑皮层。此外，我们还证明了 成年大鼠桶状回皮质神经元的简单修剪修饰 一些，但不是所有的胡须，持续时间短至1天或长达1天 30天。修剪除两个相邻胡须外的所有胡须显著增加 皮质神经元对保留的胡须和戏剧性的 减少了对修剪胡须的反应。胡须引起的变化 配对是多方面的，并取决于电池在桶中的位置 场皮质，桶与接受器中每一根胡须的关系 以及它们被修剪或保留了多长时间。四个具体目标是 确定以分析支持这些功能的电路和机制 成年大鼠大脑皮质的可塑性反应：目的1是比较 晶须配对引起的各皮质层突触的变化。 初步结果显示，颗粒上神经元先于细胞发生变化。 任何其他层。两个具体的子目标是测试胡须 在更深的层中配对可塑性需要事先在 皮层的浅层和可塑性是否取决于 谷氨酸受体机制。目标2是比较反应的极限 可在VPM丘脑皮质纤维中产生的增强 胡须配对前后的突触。目标3是分析角色 大脑外感觉调节器在大脑皮质扩散时的作用 当由晶须配对诱导时，不相邻桶之间的活动性。 我们将修剪除两个不相邻的胡须之外的所有胡须，以确定 修改连接的距离限制上的SII和POM损害 在两个完整的胡须的皮质桶之间。目标4是向人们展示 大脑皮层非感觉神经调节剂耗竭对胡须的影响 配对可塑性。