Weiss S, Kremers J, Maurer J
Department of Experimental Ophthalmology, University of Tübingen Eye Hospital, Germany.
Vis Neurosci. 1998 Sep-Oct;15(5):931-43. doi: 10.1017/s0952523898155177.
Parvocellular (P-) and magnocellular (M-) cells in the marmoset LGN can receive prominent rod input up to relatively high illuminance levels (Kremers et al., 1997b). In the present paper, we quantify rod and cone input strengths under different retinal illuminance levels. The stimulus was based on the so-called "silent substitution" method. The activities of P- and M-cells of dichromatic animals were recorded extracellularly. We were able to adequately describe the response amplitudes and phases by a vector summation of rod and cone signals. At low retinal illuminance levels, the cells' responses were determined by rod and cone inputs. With increasing illuminances the strength of the cone input increased relative to the rod strength. But, we often found significant rod inputs up to illuminances equivalent to 700 td in the human eye or more. Rod input strength was more pronounced in cells with receptive fields at large retinal eccentricities. The phase differences between rod and cone inputs suggest that the rod signals lag about 45 ms behind the cone signals.
狨猴外侧膝状体中的小细胞（P细胞）和大细胞（M细胞）在相对较高的光照水平下仍能接收显著的视杆输入（克雷默斯等人，1997b）。在本文中，我们量化了不同视网膜光照水平下视杆和视锥的输入强度。刺激基于所谓的“无声替代”方法。对二色性动物的P细胞和M细胞活动进行细胞外记录。我们能够通过视杆和视锥信号的矢量求和充分描述反应幅度和相位。在低视网膜光照水平下，细胞反应由视杆和视锥输入决定。随着光照增加，视锥输入强度相对于视杆强度增加。但是，我们经常发现在相当于人眼700 td或更高的光照水平下仍有显著的视杆输入。视杆输入强度在视网膜偏心度较大的感受野细胞中更为明显。视杆和视锥输入之间的相位差表明视杆信号比视锥信号滞后约45毫秒。
