STRUCTURE AND FUNCTION IN RETINAL NEURONS

视网膜神经元对神经递质有独特的反应。谷氨酸既兴奋又抑制，GABA反应通常对拮抗剂不敏感。该项目的目标是1）研究视网膜神经元对外源性药物刺激以及自然光刺激的反应，2）了解视网膜神经元上受体表达，视网膜神经回路和视网膜信息处理任务之间的关系。该研究检查了大鼠和斑马鱼的急性分离的视网膜神经元，以及在斑马鱼视网膜切片中鉴定的原位神经元。急性分离的双极细胞和水平细胞保持其形状，可以在培养中进行形态学鉴定。视网膜切片中的细胞通过经由记录电极的细胞内染料注射而在形态学上被识别。用电压敏感探针测定分离细胞的生理反应;用全细胞膜片钳技术记录视网膜切片中神经元的反应。通过基于互联网的教程WEBVISION传播视网膜神经生物学知识仍然是该项目的一个辅助目标。用全细胞膜片钳记录技术在视网膜切片和局部抽吸中鉴定了斑马鱼双极细胞树突上的四种谷氨酸受体类型：1。假定OFF双极的电导增加（Erev ~ 0 mV）。这种反应是红藻氨酸敏感的，CNQX被阻断。2.在假定的ON双极中，APB样电导降低（Erev ~ 0 mV）。3.谷氨酸门控氯离子电导增加假定ON双极。4.在假定的ON双极中，机制2和3的组合。双极细胞对NMDA无反应。一个双极细胞轴突终扣总是发生在ON或OFF的内丛状层亚层适当的假定的反应极性，虽然许多轴突与终扣在两个sublaminae多层。这些研究结果表明，多种谷氨酸传导机制产生的光反应在斑马鱼的ON-，但不是OFF-，双极细胞，并有可能是混合的ON和OFF信号输入的内网状层亚层a和B。- GABA，谷氨酸，视网膜，双极，细胞，神经回路，大鼠，斑马鱼，webvision

Retinal neurons express unique responses to neurotransmitters. Glutamate both excites and inhibits.GABA responses are commonly antagonist-insensitive. The project goals are 1) to study responses of retinal neurons to exogenous pharmacological stimuli, as well as natural light stimuli, and 2) to understand the relationships between receptor expression on retinal neurons, the neural circuitry of retina, and retinal information-processing tasks. The study examines acutely dissociated retinal neurons from rat and zebrafish, and in-situ neurons identified in zebrafish retinal slices. Acutely dissociated bipolar and horizontal cells retain their shapes and can be morphologically identified in culture. Cells in retinal slices are identified morphologically by intracellular dye injection via the recording electrode. Physiological responses of isolated cells are assayed with voltage-sensitive probes; whole-cell patch clamp techniques are used to record the responses of neurons in the retinal slice. Dissemination of knowledge in retinal neurobiology through WEBVISION, an internet-based tutorial, continues to be a subsidiary goal of this project. Four glutamate-receptor types were identified on zebrafish bipolar-cell dendrites with whole-cell patch clamp recordings in retinal slice and localized puffs: 1. A conductance increase (Erev ~ 0mV) in presumed OFF bipolars. Such responses were kainate sensitive and CNQX blocked. 2. An APB-like conductance decrease (Erev ~ 0mV) in presumed ON bipolars. 3. A glutamate-gated chloride conductance increase in presumed ON bipolars. 4. A combination of mechanisms 2 and 3 in presumed ON bipolars. No bipolars responded to NMDA. One bipolar-cell axonal bouton always occurred in the ON or OFF inner-plexiform-layer sublamina appropriate to the presumptive response polarity, though many axons were multistratified with boutons in both sublaminae. These findings indicate a diversity of glutamate conductance mechanisms generate the light responses in zebrafish ON-, but not OFF-, bipolar cells, and that there likely is mixing of ON and OFF signal inputs in inner-plexiform- layer sublaminas a and b. - GABA, Glutamate, Retina, Bipolar, cells, neural circuits, rat, zebrafish, webvision