FUNCTIONAL ROLE OF INDOLEAMINES IN THE MAMMALIAN RETINA

尽管生物化学和解剖学数据表明， 5-羟色胺或相关的吲哚胺是一种递质， 视网膜，我们对视网膜功能的理解， 内源性吲哚胺非常有限。 中的作用 将使用药理学操作研究递质， 兔子的视网膜 一个单独的灌流眼杯和一个 将采用完整的动脉灌注制剂进行研究 特异性β-肾上腺素能拮抗剂对反应的影响 神经节细胞。 截至目前的结果 点已经表明吲哚胺拮抗剂减少ON ON中心和OFF中心快速响应（X和Y） 神经节细胞 神经节细胞功能的其他几个方面将 现在被解决。 1. 内源性吲哚胺的作用是什么？ W细胞感受野特性的阐述？ 具体来说，只有ON途径受到影响， 吲哚胺对触发特征没有任何贡献。 (In的 过去，给定发射机的作用仅在以下情况下才得以阐明： 研究了这些W细胞）。 2. 内源性吲哚胺在明视中的作用是什么 对比近视视网膜 吲哚胺积累神经元是 广泛连接到杆双极细胞，因此， 内源性吲哚胺在暗视中有特殊作用， 视网膜。 3. 内源性吲哚胺在 神经节细胞反应性和敏感性的调节？ 的 从以前的工作中出现的假设表明， 该变送器用于增加对增量的灵敏度 光明 这一假设将通过研究 肾上腺素能药物对神经节反应性和敏感性的影响 细胞 兔视网膜已被证明是一个有用的模型系统， 发展关于变送器功能的一般化， 在其他视网膜和CNS的其他区域中证明有效。 因此，阐明内源性吲哚胺在兔 视网膜将有助于我们理解视觉处理 以及对5-羟色胺功能的理解， 哺乳动物中枢神经系统

Despite biochemical and anatomical data which indicate that serotonin or a related indoleamine is a transmitter in the mammalial retina, our understanding of the function of the endogenous indoleamine is extremely limited. The role of this transmitter will be studied using pharmacological manipulation of the rabbit retina. Both an isolated superfused eyecup and an intact arterially perfused preparation will be employed to study the effects of specific serotonergic antagonists on the responses of physiologically identified ganglion cells. Results up to this point have shown that indoleamine antagonists reduce ON responses in both ON center and OFF center brisk (X and Y) ganglion cells. Several other aspects of ganglion cell function will now be addressed. 1. What is the role of the endogenous indoleamine in the elaboration of the receptive field properties of W-cells? Specifically are only ON-pathways affected and does the indoleamine make any contribution to trigger features. (In the past the role of a given transmitter has been elucidated only when these W-cells were studied). 2. What is the role of the endogenous indoleamine in the photopic versus scoptic retina? The indoleamine-accumulating neuron is extensively connected to the rod bipolar cells, thus it is possible that the endogenous indoleamine has a specific role in scotopic retina. 3. What role does the endogenous indoleamine have in the modulation of ganglion cell responsivity and sensitivity? The hypothesis which has emerged from previous work suggests that this transmitter serves to increase the sensitivity to increments of light. This hypothesis will be tested by studying the effects of serotonergic drugs on the responsivity and sensitivity of ganglion cells. The rabbit retina has proven to be a useful model system in which to develop generalizations about transmitter function which have proven valid in other retinae and also other regions of the CNS. Thus, elucidating the role of the endogenous indoleamine in rabbit retina will contribute to our understanding of visual processing and to the understanding of the function of serotonin in the mammalian CNS.