RECEPTIVE FIELDS OF LAYER IV (BARREL FIELD) NEURONS

第四层（桶状场）神经元的感受野

• 批准号: 2609612
• 负责人: Ford Francis Ebner
• 金额: $ 27.25万
• 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 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2609612
• 关键词: NMDA receptors; acetylcholine; brain electrical activity; brain mapping; central neural pathway /tract; developmental neurobiology; histology; laboratory rat; microscopy; neural information processing; neural plasticity; neuroanatomy; neurotransmitter transport; norepinephrine; sense organs; sensory feedback; single cell analysis; somesthetic sensory cortex; stimulus /response; 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 整个产后生活的周边。中心假设 拟议的研究是，持续的简单积极偏见 选定的晶须的活动足以增强其目标 通过谷氨酸受体机械主义在皮质中突触。研究 将在大鼠晶须到桶形皮层途径中进行 因为每个晶须Follide中的离散，非重叠的受体 在枪管场中保持珍贵的地形和二层IV层 皮质。此外，我们已经证明了 成年大鼠枪管场皮质中的神经元通过简单修剪而修饰 有些（但不是全部）在短达1天或最多的时间内 30天。修剪除两个相邻晶须外的所有除外 皮质神经元对幸免的胡须和极大的反应 减少了对晶须的反应。晶须引起的变化 配对是多方面的，并取决于枪管中的单元位置 田间皮层，枪管与接收中的每个晶须的关系 野外以及他们修剪或幸免了多长时间。四个具体目标是 确定分析支持这些的电路和机制 成年大鼠皮层中的塑料反应：目标＃1是比较 晶须配对引起的每个皮层中突触的变化。 初步结果表明，在细胞中，上神经元在 任何其他层。两个特定的子目标是测试是否晶须 在较深层中配对可塑性需要事先更改 皮质的浅层层以及可塑性是否取决于 谷氨酸受体机制。目标＃2是比较响应的限制 可以在VPM丘脑皮层纤维中生成的增强 晶须配对前后突触。目标＃3是分析角色 在传播中的额外感官调节器到桶形皮层 通过晶须配对诱导非粘液桶之间的活性。 我们将修剪除两个非粘性晶须以外的所有人，以确定 用于修改连接的距离限制的SII和POM病变 在两个完整的胡须的皮质桶之间。目标＃4是显示 晶须上皮质中非感官神经调节剂耗尽的影响 配对可塑性。