CRCNS: Biophysical properties of parallel neural circuits serving night vision

这个项目的主要目标是联合收割机结合实验和计算的方法，以发展一个详细的了解如何在夜间视觉过程中的个体视网膜神经元和突触的生物物理特性形状的视觉信息的并行处理。这个项目是两个神经生物学家和两个应用数学家之间的合作。我们将实验和模型计算哺乳动物视网膜的神经回路，subserves夜间（暗视觉）的视觉。基本的电路已经被很好地描述了：由视杆细胞吸收的光子产生神经信号，这些信号通过一系列中间神经元分布到多种类型的视网膜神经节细胞（GC），视网膜的输出细胞。这些中间神经元发出信号， 其他的则通过化学和电突触。每种GC类型都有独特的光反应，这被认为反映了其独特的突触前电路的特性。该电路使每种GC类型能够编码视觉场景的独特特征，从而促进高级大脑区域的进一步抽象，最终指导行为。通过对每个组件进行表征和仔细建模，将组件组装成一个综合模型，并通过实验验证和改进整个模型，我们将确定并行视网膜微电路的生物物理特性如何产生不同的GC输出。与公共卫生的相关性：许多视网膜病变会导致感光细胞（视杆细胞和视锥细胞）死亡， 剥夺了GC的正常输入。最近，已经开发了光遗传学方法，其最终目标是通过使视网膜神经元直接对光响应来在缺乏感光感受器功能的情况下恢复视力。在这里，我们希望确定关键的神经元，光敏性可能被赋予允许恢复的能力，在一个广泛的动态范围内编码的视觉世界的最相关的功能。 该项目的目的是解决国家眼睛和视力研究计划中视网膜疾病计划的两个明确目标：1）增加对感光后适应的理解（即，神经回路中的增益控制）和2）增加对神经网络内视网膜细胞相互作用如何产生 可以被解释为视觉图像的信号。

The main goal of this project is to combine experimental and computational approaches to develop a detailed understanding of how the biophysical properties of individual retinal neurons and synapses shape the parallel processing of visual information during night vision. This project is a collaboration between two neurobiologists and two applied mathematicians. We will characterize experimentally and model computationally the neural circuitry of the mammalian retina that subserves night (scotopic) vision. The basic circuitry is well-described: photons absorbed by rod photoreceptors generate neural signals that are distributed to multiple types of retinal ganglion cells (GCs), the output cells of the retina, via a series of interneurons. These interneurons signal each other via chemical and electrical synapses. Each GC type has a unique light response, which is presumed to reflect the properties of its unique presynaptic circuitry. This circuitry enables each GC type to encode a unique feature of the visual scene, thereby facilitating further abstractions by higher brain areas that ultimately guide behavior. By characterizing and carefully modeling each component, by assembling the components into a comprehensive model, and by validating and refining the overall model experimentally, we will determine how diverse GC outputs emerge from the biophysical properties of parallel retinal microcircuits.Relevance to public health: Many retinal pathologies cause photoreceptor (rod and cone) death, which deprives GCs of their normal inputs. Recently, optogenetic approaches have been developed with the ultimate goal of restoring vision in the absence of phoptoreceptor function by making retinal neurons directly responsive to light. Here, we hope to identify key neurons to which photosensitivity may be endowed to permit the restoration of the ability to encode over a wide dynamic range the most relevant features of the visual world. The aims of this project address two explicit goals of the Retinal Diseases Program in the National Plan for Eye and Vision Research: 1) Increasing understanding of post-photoreceptor adaptation (i.e., gain control in neural circuits) and 2) Increasing understanding of how retinal cellular interactions within neural networks generate signals that are interpretable as visual images.