AMACRINE CELL FUNCTION IN THE RETINA

视网膜中的无精细胞功能

基本信息

批准号：
2161472
负责人：
Stewart Allen Bloomfield
金额：
$ 23.96万
依托单位：
NEW YORK UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-03-01 至 1998-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2161472
关键词：
amacrine cells chemical structure function computer simulation dendrites evoked potentials fluorescence microscopy fluorescent dye /probe histochemistry /cytochemistry laboratory rabbit neural transmission neuroanatomy neurotransmitters nontherapeutic iontophoresis retinal bipolar neuron retinal ganglion single cell analysis synapses visual feedback

项目摘要

Amacrine cells are laterally-oriented interneurons in the proximal retina which are located strategically to influence the response properties of ganglion cells. Thus, amacrine cells play a key role in determining the visual information carried by the final output pathway of the retina to higher brain centers. Although retinal amacrine cells have been the subject of numerous morphological and pharmacological studies, much of our knowledge of amacrine cell function in the mammal has been attained indirectly from work directed at ganglion cells or inferred from studies of lower vertebrates. The vast majority of retinal neurotransmitters, including peptides, are used by amacrine cells to affect ganglion cell activity. It is likely, then, that retinopathies derived from imbalances of neurotransmitters would be localized to circuitry subserved by amacrine cells. Unfortunately, the physiology of amacrine cells, and thus the function of many of these transmitters, is presently unclear. The long term goal of this research is to determine the physiological response properties expressed by amacrine cells in the mammalian retina and to correlate these with their morphologies. The experimental strategy is not only to determine the correlations that exist between amacrine cell structure and function but also to form a physiological framework to incorporate the available morphological and pharmacological data. The basic method used is intracellular recording from neurons in the superfused, retina-eyecup preparation of the rabbit. Physiologically-characterized cells are subsequently labeled with intracellular stains such as horseradish peroxidase (HRP) to determine their soma-dendritic morphologies. Recent findings indicate that amacrine cells show a much richer variety of responses than thought previously, such as orientation and direction sensitivity. Thus, the specific aims of the proposed research focus on complex response properties of amacrine cells and their generation. These include: (1) To determine the direction sensitivity of the cholinergic starburst amacrine cells and the mechanism underlying its generation. (2) To examine electrical coupling between the orientation-sensitive Ae-type horizontal cells and between the orientation-biased amacrine cells in the rabbit. This line of research will establish whether electrical synapses preserve and expand the orientation sensitivity of these cells across their extensive receptive fields. (3) To study the orientation sensitivity of bipolar cells in the rabbit to determine if they may provide the route for passage of orientation-sensitive visual information from horizontal to amacrine cells. (4) To examine the role of active propagation of synaptic inputs in shaping the receptive fields of amacrine cells.

无小细胞在视网膜近端是横向导向的中间神经元从战略上影响的，以影响神经节细胞。因此，无聚细胞在确定视网膜最终输出途径携带的视觉信息较高的大脑中心。虽然视网膜无花细胞一直是大量形态学和药理研究的主题，大部分我们对哺乳动物中的无链氨氨酸细胞功能的了解已得到达到间接来自针对神经节细胞或从研究推断的工作下脊椎动物。绝大多数视网膜神经递质，包括肽在内，被无聚细胞用于影响神经节细胞活动。因此，可能是从失衡中得出的视网膜病神经递质的含量将定位于通过无小细胞。不幸的是，无聚细胞的生理学，以及因此，许多这些发射机的功能目前尚不清楚。这项研究的长期目标是确定生理哺乳动物视网膜中的无链氨酸细胞表达的响应特性并将其与它们的形态相关联。实验策略不仅是确定之间存在的相关性无小细胞结构和功能，但也形成生理框架合并可用的形态和药理数据。所使用的基本方法是来自神经元的细胞内记录兔子的超级凹陷，视网膜尤其的准备。随后将生理特征的细胞标记为细胞内污渍，例如辣根过氧化物酶（HRP），以确定他们的躯体树突形态。最近的发现表明无聚细胞显示出比思想的多种反应以前，例如方向和方向灵敏度。因此，拟议研究的具体目的重点是复杂响应无长熟细胞及其产生的特性。这些包括：（1）确定胆碱能星爆肿瘤的方向敏感性细胞和产生的机制。（2）检查方向敏感的AE型水平的电气耦合细胞以及兔子中的方向偏置无分细胞。这一研究将确定电气突触是否保存并扩大这些细胞的方向敏感性广泛的接受场。（3）研究兔子中的双极细胞，以确定它们是否可以提供途径用于通过水平的方向敏感视觉信息的传递到无小细胞。（4）检查主动传播的作用突触输入在塑造无长熟细胞的接受场中。