刺激模式对视网膜网络连接及信息编码方式的影响

Vision is crutial for humans and other primates, and it is one of the most important ways to get information from the environment. How the visual system effectively encodes the visual environment is one of the impormant issues of neuroscience reseraches. Retina is the first stage for visual neural information processing. Although retinal neurons are niced layed according to the cells' morphological and functional classification, the retinal neurons are with very complicated neural network, the connectivity and efficiency for information transmission among the neurons are adjustable under various visual conditions. Ganglion cells are the only output neurons of retina, and they show various firing pattens under different visual stimulation conditions. Researchs show that retinal ganglion cells can encode external stimulation via various coding strategies, including rate coding, precise time coding and population coding, etc. Thus, it is intriguing to ask the following questions: (1) how is the retinal neuronal network dynamically adjusted in response to differnet visual stimulation? and (2) what is the relationship between the visual stimulation and the neuronal coding strategy? Based on electrophysiological and pharmacological experiments performed on retina, in combining with information theory, the present study will be examining the relationship among stimulation pattern, retinal network connectivity and coding strategy of retinal neurons, and explore relevant physiological functional significance.

视觉是人类和高等动物认识客观世界的主要方式之一。视觉系统如何有效地编码丰富多彩的视觉场景长久以来是神经科学研究关注的问题之一。视网膜是视觉神经信息处理的第一环节。虽然视网膜中神经元根据形态和功能有着明显的分层结构，但是神经元之间的网络连接十分复杂，并且神经元之间的连接强度及信息传递效率也会随视觉条件而变化。神经节细胞是视网膜唯一的输出神经元，在不同视觉刺激条件下会表现不同的放电活动模式。研究表明神经节细胞可以利用多种编码方式，包括频率编码、时间结构编码以及协同编码等，有效地编码外界刺激。那么，视网膜神经元间的网络连接如何在应对视觉刺激时实现动态调节，神经元编码方式与视觉刺激模式之间又存在怎样的联系？本课题将以视网膜电生理及药理实验为基础，结合信息论方法，考察刺激模式与视网膜网络连接以及神经元编码方式的关系，并探讨其生理意义。