Anishchenko Anastacia, Greschner Martin, Elstrott Justin, Sher Alexander, Litke Alan M, Feller Marla B, Chichilnisky E J
Dept. of Molecular and Cell Biology, UC Berkeley,Berkeley, CA 94720, USA.
J Neurophysiol. 2010 Apr;103(4):1856-64. doi: 10.1152/jn.00896.2009. Epub 2010 Jan 27.
A characteristic feature of adult retina is mosaic organization: a spatial arrangement of cells of each morphological and functional type that produces uniform sampling of visual space. How the mosaics of visual receptive fields emerge in the retina during development is not fully understood. Here we use a large-scale multielectrode array to determine the mosaic organization of retinal ganglion cells (RGCs) in rats around the time of eye opening and in the adult. At the time of eye opening, we were able to reliably distinguish two types of ON RGCs and two types of OFF RGCs in rat retina based on their light response and intrinsic firing properties. Although the light responses of individual cells were not yet mature at this age, each of the identified functional RGC types formed a receptive field mosaic, where the spacing of the receptive field centers and the overlap of the receptive field extents were similar to those observed in the retinas of adult rats. These findings suggest that, although the light response properties of RGCs may need vision to reach full maturity, extensive visual experience is not required for individual RGC types to form a regular sensory map of visual space.
每种形态和功能类型的细胞在空间上的排列方式，这种排列对视觉空间进行均匀采样。在发育过程中，视网膜中视觉感受野的镶嵌是如何形成的，目前尚未完全了解。在这里，我们使用大规模多电极阵列来确定大鼠在睁眼前后及成年时视网膜神经节细胞（RGC）的镶嵌组织。在睁眼时，我们能够根据大鼠视网膜中两种类型的ON RGC和两种类型的OFF RGC的光反应和内在放电特性可靠地将它们区分开来。尽管此时单个细胞的光反应尚未成熟，但每种已识别的功能性RGC类型都形成了一个感受野镶嵌，其中感受野中心的间距和感受野范围的重叠与成年大鼠视网膜中观察到的情况相似。这些发现表明，尽管RGC的光反应特性可能需要视觉才能完全成熟，但对于单个RGC类型形成视觉空间的规则感觉图谱来说，并不需要广泛的视觉经验。
