不同類型RGC的間隙連接產生偏移ON-OFF感受野
作者:
小柯機器人發布時間:2020/11/25 16:22:35
美國西北大學Gregory W. Schwartz課題組取得最新進展。他們發現不同類型的視網膜神經節細胞(RGCs)之間的間隙連接產生了偏移的ON-OFF感受野。這一研究成果發表在2020年11月23日出版的《自然-神經科學》上。
他們報告發現F-mini-ON RGC中的ON和OFF受體子域之間的系統空間偏移。令人驚訝的是,此特性並非來自空間偏移的ON和OFF層樹突,而是來自通過間隙連接到另一種類型的RGC(F-mini-OFF)的電突觸網絡。他們表明,這些RGC的不對稱形態和連通性可以解釋它們的感受野偏移,並且他們使用多單元模型探索了感受野偏移對總體中邊緣位置表示精度的影響。這個RGC網絡形成了一個新的電通道,在視網膜輸出層內結合了ON和OFF前饋通路。
據介紹,在脊椎動物的視網膜中,視覺空間中神經元感受野的位置與突觸輸入到其樹突上的物理位置緊密對應,這種關係稱為視網膜位置圖。
附:英文原文
Title: An offset ON–OFF receptive field is created by gap junctions between distinct types of retinal ganglion cells
Author: Sam Cooler, Gregory W. Schwartz
Issue&Volume: 2020-11-23
Abstract: In the vertebrate retina, the location of a neuron’s receptive field in visual space closely corresponds to the physical location of synaptic input onto its dendrites, a relationship called the retinotopic map. We report the discovery of a systematic spatial offset between the ON and OFF receptive subfields in F-mini-ON retinal ganglion cells (RGCs). Surprisingly, this property does not come from spatially offset ON and OFF layer dendrites, but instead arises from a network of electrical synapses via gap junctions to RGCs of a different type, the F-mini-OFF. We show that the asymmetric morphology and connectivity of these RGCs can explain their receptive field offset, and we use a multicell model to explore the effects of receptive field offset on the precision of edge-location representation in a population. This RGC network forms a new electrical channel combining the ON and OFF feedforward pathways within the output layer of the retina.
DOI: 10.1038/s41593-020-00747-8
Source: https://www.nature.com/articles/s41593-020-00747-8