AMACRINE CELL FUNCTION IN MAMMALIAN RETINA

无长突细胞构成了一类独特的无轴突神经元 它们在突触前和突触后的接触在视觉加工中起辅助作用 内层视网膜。尽管无长突细胞一直是 许多形态和药理学研究的主题， 令人惊讶的是，很少有研究直接检查 他们的生理机能。因此，全系列的无长突细胞 响应属性尚未确定，我们的大部分 关于无长突细胞功能的知识是间接获得的， 来自针对神经节细胞的生理作用。一个 提出了多学科的方法来研究生理学， 无长突细胞的形态和药理相互作用 兔子的视网膜。这项研究的长期目标是 阐明无长突细胞对双极神经节细胞的影响 传播，以及这些相互作用如何有助于 哺乳动物视网膜神经节细胞反应的形成。 提出了三大具体目标。第一个目标是 确定不同的光诱发反应和感受野 兔无长突细胞所显示的特性。这将是 通过从无长突细胞中获取细胞内记录来完成 兔视网膜中的细胞-眼球在呈现不同的 光刺激。下面将描述无长突细胞的感受野 利用先前研究中使用的相同标准来表征 神经节细胞，包括复杂的反应特性。我的 初步数据显示，兔无长突细胞表现出一些 以前被认为是复杂的感受野特性的 仅限于神经节细胞，如方向和方向 选择性。第二个目标是确定其形态 无长突细胞，并将其与其反应特性相关联。 生理特征的无长突细胞将被标记为 辣根过氧化物酶(HRP)显示其树突 建筑。然后，获得的神经元轮廓将是 与高尔基和组织化学中描述的无长突细胞相比 突触连接和/或神经递质是 为人所知。第三个目标是审查推定人的行为。 无长突细胞递质GABA和乙酰胆碱在无长突上的分布 细胞反应。这项工作将阐明 特别是无长突细胞之间的相互连接 在这些发射机的帮助下。这些结果的比较 与已有的兔神经节药理研究结果一致 将使细胞更精确地定位特定的 传输器效应，并提供对哪个神经节的深入了解 细胞反应特性依赖于无长突细胞输入。

Amacrine cells constitute a unique class of axonless neurons whose pre- and postsynaptic contacts subserve visual processing in the inner retina. Although the amacrine cells have been the subject of numerous morphological and pharmacological studies, there have been surprisingly few studies which directly examined their physiology. As a result, the full range of amacrine cell response properties has yet to be determined and much of our knowledge of amacrine cell function has been attained indirectly, from physiological work directed at the ganglion cells. A multidisciplinary approach is proposed to study the physiology, morphology, and pharmacological interactions of amacrine cells in the rabbit retina. The long-term goal of this research is to elucidate how amacrine cells influence bipolar to ganglion cell transmission, and how these interactions contribute to the formation of ganglion cell responses in the mammalian retina. Three major specific aims are proposed. The first aim is to determine the different light-evoked response and receptive field properties displayed by rabbit amacrine cells. This will be accomplished by obtaining intracellular recordings from amacrine cells in the rabbit retina-eyecup during presentation of various photic stimuli. Amacrine cell receptive fields will be described utilizing the same criteria used in prior studies to characterize ganglion cells, including complex response properties. My preliminary data indicate that rabbit amacrine cells exhibit some of the complex receptive field properties formerly thought to be limited to ganglion cells, such as direction and orientation selectivity. The second aim is to determine the morphology of amacrine cells and correlate this with their response properties. Physiologically-characterized amacrine cells will be labelled with horseradish peroxidase (HRP) to visualize their dendritic architectures. The neuronal profiles obtained will then be compared to amacrine cells described in Golgi and histochemical studies whose synaptic connections and/or neurotransmitters are known. The third aim is to examine the actions of the putative amacrine cell transmitter, GABA and acetylcholine, on amacrine cell responses. This work will elucidate the extent and specifically of the interconnections between amacrine cells subserved by these transmitters. Comparison of these results with those of prior pharmacological studies of rabbit ganglion cells will be made to localize more precisely the sites of specific transmittter effects, and to provide insights into which ganglion cell response properties are dependent on amacrine cell input.