NEURAL SIGNALLING IN THE RETINA

脊椎动物光感受器的电信号是由 外段钠离子向内电流的调制。这个 钠进入外段的机制尚不清楚，存在 几乎没有确凿的证据表明光是如何控制毛孔的电导的 或调节钠离子内流的载体分子。我们建议研究 光敏电导的性质及其机理 对照，使用膜片钳和吸电极记录，光学 测量，并将物质注入孤立的棒中。我们打算 回答以下问题： 1)电导、温度依赖性和动力学是什么？ 生物膜表面光敏“通道”行为的研究 杆子外节？ 2)通道如何响应可能的内部传输器，例如 钙离子与环状GMP？ 3)棒材内部游离钙浓度是如何变化的 对光的反应？ 4)电暗的连续分量的来源是什么？ 棒的声音？ 5)锥体暗噪声的大小和功率谱是多少？ 噪音是如何产生的？ 6)在暗适应杆的外节是否有一个纵向的 体内钠浓度梯度？是钠的梯度导致的 外膜顶端和底端的不同转导动力学 细分市场？

The electrical signals of vertebrate photoreceptors are generated by modulation of an inward current of sodium ions at the outer segment. The mechanism by which Na enters the outer segment is not known, and there is little solid evidence about how light controls the conductance of the pores or carrier molecules that mediate the Na influx. We propose to examine the properties of the light-sensitive conductance and the mechaism of its control, using patch clamp and suction electrode recording, optical measurements, and injection of substances into isolated rods. We intend to approach the following questions: 1) What is the electrical conductance, temperature dependence and kinetic behaviour of the light-sensitive "channel" in the surface membrane of the rod outer segment? 2) How does the channel respond to possible internal transmitters such as CA ions and cyclic GMP? 3) How does the internal concentration of free Ca change during a rod's response to light? 4) What is the origin of the continuous component of the electrical dark noise of rods? 5) What is the magnitude and power spectrum of the dark noise of cones, and how is the noise generated? 6) In the outer segment of a dark-adapted rod is there a longitudinal gradient of internal Na concentration? Is a Na gradient responsible for the different kinetics of transduction at the tip and base of the outer segment?