HORIZONTAL CELL INFLUENCES UPON GANGLION CELL PROPERTIES

本研究项目是对突触的实验研究。 脊椎动物视网膜的组织。虽然接受能力很强 神经节细胞的视野特性与视觉密切相关 功能，对突触前通路知之甚少 这是这些细胞的特性的基础。这项研究 提案将考察水平单元格对 兔视网膜神经节细胞的感受野特性 将调查这一水平细胞是否为神经节细胞 通路是由光强度和突触输入调制的 兔视网膜和鱼视网膜的水平细胞。 水平细胞将被细胞内电流极化 在从附近的单单元同时记录注射的同时 神经节细胞尖峰活动。这些实验将决定 水平细胞是否参与神经节细胞的感受性 字段属性及其周围环境，以及是否 水平细胞影响部分神经节细胞，但不是全部。 兔视网膜的分类。因为不同类型的兔子 水平细胞接受不同比例的杆和锥体 这些像元类型的输入、极化，将由 染料注入，将有助于揭示杆状和锥体路径 对神经节细胞感受野的不同影响 属性。递质拮抗剂也将在 向水平细胞注入电流以确定是否 已知作用的药物可以改变电流的影响 注射治疗神经节细胞放电。这些后面的数据可以 阐明视网膜外层的回路。更多关于 鲤鱼和兔子将研究可能的调制 水平细胞感受野大小和反应性 神经节细胞周围的大小和对长时间黑暗的敏感性 适应、多巴胺和环磷酸腺苷。 具有神经电路和递质功能方面的知识 哺乳动物视网膜将增加对人类视网膜的了解 过程，提高对视网膜病变的诊断和 为视网膜疾病的药物治疗提供依据。这个 多巴胺能神经元对大鼠脑内神经元的特异性影响 视网膜将进一步加深我们对视觉病理的理解 与帕金森氏症有关。

This research project is an experimental study of the synaptic organization of the vertebrate retina. Although the receptive field properties of ganglion cells are quite pertinent to visual function, little is known concerning the presynaptic pathways which underlie the properties of these cells. This research proposal will examine the influence of horizontal cells upon the receptive field properties of ganglion cells in the rabbit retina and will investigate whether this horizontal cell to ganglion cell pathway is modulated by light level and by synaptic input onto horizontal cells in the rabbit and fish retinas. Horizontal cells will be polarized by intracellular current injections while simultaneously recording from nearby single-unit ganglion cell spike activity. These experiments will determine whether horizontal cells contribute to ganglion cell receptive field properties in addition to their surrounds, and whether horizontal cells influence some, but not all, of the ganglion cell classes of the rabbit retina. Because different types of rabbit horizontal cells receive different proportions of rod and cone input, polarization of these cell types, which will be identified by dye injection, will help reveal whether rod and cone pathways exert different effects upon ganglion cell receptive field properties. Transmitter antagonists will also be applied during current injections into horizontal cells to determine whether drugs with known actions can alter the effects of current injection on ganglion cell discharges. These latter data may elucidate circuitry of the outer retina. Additional studies on the carp and rabbit will investigate the possible modulation of horizontal cell receptive field size and responsiveness and ganglion cell surround size and sensitivity by prolonged dark adaptation, dopamine and cyclic AMP. Knowledge of neural circuitry and transmitter function in mammalian retina will increase understanding of human retinal processes, enhance the diagnosis of retinal pathologies and provide the basis for drug therapy for retinal disorders. The identification of specific influences of dopaminergic neurons in the retina will further our understanding of visual pathologies associated with Parkinson's disease.