DYNAMIC PROPERTIES OF VISUAL CORTICAL CIRCUITS

视觉皮质回路的动态特性

• 批准号: 6180001
• 负责人: Judith A Hirsch
• 金额: $ 35.82万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180001
• 关键词: cats; electrostimulus; intercellular connection; lateral geniculate body; neural information processing; neural inhibition; neural transmission; neuroanatomy; neurons; neurophysiology; single cell analysis; synapses; visual cortex; visual pathways; visual stimulus; voltage /patch clamp

DESCRIPTION (Adapted From The Applicant's Abstract): How does the synaptic physiology of the cortical microcircuit regulate signal detection in striate cortical neurons? To approach this broad issue we analyze the synaptic basis of neuronal response structures at successive cortical stages and the connections that convey information from one cortical level to the next. The work is made possible by the advance of whole-cell recording in vivo, a technique that gives a highly resolved view of the postsynaptic events evoked during vision and allows intracellular staining of single neurons. AIM 1) The push-pull model of the simple receptive field holds that signals of reverse contrast have the opposite effect: bright stimuli presented to an on subregion evoke firing, whereas dark ones reduce activity. Two mechanisms have been proposed to account for the pull. One is passive withdrawal of excitation from the thalamus; the other is pharmacological analyses of the visual response. Further, we will determine if the push-pull model fully accounts for the spatial distribution of excitation and inhibition in the simple receptive field and if it predicts orientation tuning. AIM 2) Why do many complex cells respond poorly to the same stimuli that drive simple cells well? Our hypothesis is that the successive cortical stages employ different sets of synaptic mechanisms to regulate stimulus selectivity. If true, then complex cells that receive direct thalamic input should have response structures different from those of cells outside thalamic reach. This prediction is tested by comparing responses of cells in layer 4 with those in layer 2+3 to the same stereotyped stimulus. The anatomical substrate for information transfer from the first to second cortical stage is determined by labeling the connections extending from layer 4 to 2+3. A knowledge of how the brain operates in the everyday situation provides a standard against which to judge changes that occur in the course of various disorders, as well as a model system on which to test drugs developed to treat illness. From this perspective, the visual cortex is an obvious site to study; its function and anatomy are better resolved than any other cortical region. A deeper understanding of cortical synaptic mechanisms provides insight into processes that go awry during disease. For example, the work proposed here bears directly on a central theme in research on amblyopia, the examination of how abnormal visual experience leads to changes in central processing.

描述（改编自申请人的摘要）：突触如何 皮层微电路的生理学调节条纹中的信号检测 皮质神经元？为了解决这个广泛的问题，我们分析了 连续的皮质阶段和连接处的神经元反应结构 那将信息从一个皮质层传达到另一个皮质层。这项工作是完成的 通过在体内录制全细胞记录的前进，这是一种提供的技术 在视觉期间引起的突触后事件的高度解决的观点和 允许单神经元的细胞内染色。目标1） 简单的接收场认为，反向对比的信号具有 相反的效果：明亮的刺激呈现给子区域的唤起， 而黑暗的人会减少活动。已经提出了两种机制来解释 为了拉。一种是被动从丘脑中激发的激发。这 其他是视觉反应的药理分析。此外，我们会的 确定推杆模型是否充分说明了空间分布 简单接收场中的激发和抑制作用，如果预测 方向调整。目标2）为什么许多复杂的细胞对相同的反应不佳 刺激简单细胞的刺激？我们的假设是连续的 皮质阶段采用不同的突触机制来调节 刺激选择性。如果是真的，那么接收直接丘脑的复杂细胞 输入应具有与外部单元格不同的响应结构 丘脑覆盖范围。通过比较细胞中的细胞反应来测试该预测 第4层与第2层+3相同的刺激。这 从第一皮层到第二皮层的信息传递的解剖基板 阶段是通过标记从第4层到2+3的连接来确定的。 了解大脑在日常情况下如何运作的知识提供了 判断各种过程中发生的变化的标准 疾病以及用于测试用于治疗的药物的模型系统 疾病。从这个角度来看，视觉皮层是一个明显的研究地点。 它的功能和解剖结构比任何其他皮质区域都更好。一个 对皮质突触机制的更深入了解 疾病期间出现问题的过程。例如，这里提出的工作 直接以弱视研究的研究为中心主题 异常的视觉体验如何导致中央处理的变化。