SYNAPTIC MECHANISMS IN THE VERTEBRATE RETINA

脊椎动物视网膜中的突触通讯将利用 药理学方法。 实验将在 两栖动物和兔视网膜灌注细胞内 电生理技术。 氨基酸神经递质的作用， 兴奋性和抑制性，在介导突触传递的 将研究视觉信息。 实验将集中在 光感受器和双极神经递质的分析， 它可能使用一种类似谷氨酸的神经递质， 可以释放天冬氨酸的细胞。 在远端视网膜中，PI将使用 谷氨酸类似物来测试他的模型， 一类二级神经元优先与不同的 谷氨酸的构象 视杆细胞和视锥细胞的药理学 将比较神经传递。 在近端视网膜中，PI计划确定OFF双极，如 ON双极型可使用兴奋性氨基酸神经递质。 在 此外，在第三组中， 顺序神经元将被检查，以评估这种反应二分法是否 反映了兴奋性氨基酸受体的双重性 神经元 初步证据表明，一种持续的， 无长突细胞可能存在于泥小狗，这种可能性， 将研究其功能意义。 丝氨酸在近端视网膜和PI中具有有效的抑制作用 计划评估这些行为是否反映了真正的神经递质 这种氨基酸的作用。 单细胞染色将与上述检查结合进行 试图将细胞形态学与生理学联系起来的实验， 药理学 这项研究提供了选择性地操纵各种 视网膜中的视觉通路。 这些操作可用于开发 用于诊断视网膜功能障碍的临床方案。 特别是， 许多视网膜疾病涉及光感受器变性， 了解感光神经递质的作用， 为这些疾病提供了重要的见解。

Synaptic communication in the vertebrate retina will be analyzed utilizing a pharmacological approach. Experiments will be performed in the superfused retinas of amphibians and rabbits using intracellular electrophysiological techniques. The role of amino acid neurotransmitters, both excitatory and inhibitory, in mediating the synaptic transfer of visual information will be studied. Experiments will concentrate on the analysis of the neurotransmitters of photoreceptors and bipolars, both of which may use a glutamate-like neurotransmitter, and a class of amacrine cells which may release aspartate. In the distal retina, the PI will use glutamate analogs to test his model that the synaptic receptors on each class of second-order neuron preferentially binds to a different conformation of glutamate. The pharmacology of rod and cone neurotransmission will be compared. In the proximal retina, the PI plans to determine if the OFF bipolar, like the ON bipolar, may use an excitatory amino acid neurotransmitter. In addition, the pharmacology of transient vs. sustained excitation in third order neurons will be examined to assess whether this response dichotomy reflects a duality in the excitatory amino acid receptors on these neurons. Preliminary evidence hints that a sustained, aspartate-releasing ON amacrine cell may be present in the mudpuppy and this possibility and its functional significance will be investigated. Serine has potent inhibitory actions in the proximal retina and the PI plans to evaluate whether these actions reflect a true neurotransmitter role for this amino acid. Single cell staining will be performed in conjunction with the above experiments in an attempt to correlate cell morphology with physiology and pharmacology. This research offers the possibility of selectively manipulating various visual pathways in the retina. These manipulations can be used to develop clinical protocols for diagnosing retinal malfunctions. In particular, many retinal diseases involve photoreceptor degeneration and an understanding of the action of the photoreceptor neurotransmitter may provide important insights into these diseases.