Nature:视觉系统中光感受器网络的输入输出对应图

2010-10-08 00:00 · Cherry

色视觉在视网膜中形成,在灵长类动物中,视觉处理的第一阶段由视锥细胞和神经节细胞的重叠格组成,其中每个对视觉空间统一取样。 彩色感觉(色觉)由对来自不同视锥细胞类型的信号所做比较,但这些输入信号是怎样被神经节细胞(它们传输视网膜的输出)结合在一起的多年来一直是一个有争议的问题。现

色视觉在视网膜中形成,在灵长类动物中,视觉处理的第一阶段由视锥细胞和神经节细胞的重叠格组成,其中每个对视觉空间统一取样。

彩色感觉(色觉)由对来自不同视锥细胞类型的信号所做比较,但这些输入信号是怎样被神经节细胞(它们传输视网膜的输出)结合在一起的多年来一直是一个有争议的问题。现在,利用大尺度多电极阵列和细颗粒视觉模拟,Field等人绘制出了单个视锥细胞输入相对于整个神经节细胞群的位置和类型图,从而以前所未有的分辨率和尺度获得输入-输出对应图。

 

推荐英文摘要:

Nature doi:10.1038/nature09424

Functional connectivity in the retina at the resolution of photoreceptors

Greg D. Field,Jeffrey L. Gauthier,Alexander Sher,Martin Greschner,Timothy A. Machado,Lauren H. Jepson,Jonathon Shlens,Deborah E. Gunning,Keith Mathieson,Wladyslaw Dabrowski,Liam Paninski,Alan M. Litke" E. J. Chichilnisky

To understand a neural circuit requires knowledge of its connectivity. Here we report measurements of functional connectivity between the input and ouput layers of the macaque retina at single-cell resolution and the implications of these for colour vision. Multi-electrode technology was used to record simultaneously from complete populations of the retinal ganglion cell types (midget, parasol and small bistratified) that transmit high-resolution visual signals to the brain. Fine-grained visual stimulation was used to identify the location, type and strength of the functional input of each cone photoreceptor to each ganglion cell. The populations of ON and OFF midget and parasol cells each sampled the complete population of long- and middle-wavelength-sensitive cones. However, only OFF midget cells frequently received strong input from short-wavelength-sensitive cones. ON and OFF midget cells showed a small non-random tendency to selectively sample from either long- or middle-wavelength-sensitive cones to a degree not explained by clumping in the cone mosaic. These measurements reveal computations in a neural circuit at the elementary resolution of individual neurons.

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