Kremers J, Weiss S, Zrenner E
Department of Experimental Ophthalmology, University of Tübingen Eye Hospital, Germany.
Vision Res. 1997 Oct;37(19):2649-60. doi: 10.1016/s0042-6989(97)00090-4.
We measured the temporal modulation transfer functions (TMTFs) of cells in the marmoset lateral geniculate nucleus (LGN) at three different luminance levels, and described the responses with a linear model. It was found that qualitatively there are many similarities with the temporal response properties of macaque and marmoset retinal ganglion cells. M-cells displayed stronger attenuation at lower temporal frequencies, and showed more nonlinearities (such as saturation and a contrast gain control) than P-cells. We therefore propose that the temporal properties of the visual system of New and Old World monkeys are similar at least up to the LGN. However, there are some quantitative differences, indicating that response alterations take place at the stage of synaptic transmission in the LGN. The most important are an attenuation of the responses to higher temporal frequencies and the smaller differences between parvo- and magnocellular cell responsivities. Cell responses to square-wave modulation were also measured and compared with predictions from a linear systems analysis. The linear systems analysis gave reasonable predicted responses to square-wave modulation, but these predictions were poor than those for retinal ganglion cells, indicating that additional nonlinearities are introduced at the synaptic transition in the LGN.
我们在三种不同的亮度水平下测量了狨猴外侧膝状核（LGN）中细胞的时间调制传递函数（TMTFs），并用线性模型描述了这些反应。结果发现，从性质上讲，其与猕猴和狨猴视网膜神经节细胞的时间反应特性有许多相似之处。M细胞在较低时间频率下表现出更强的衰减，并且比P细胞表现出更多的非线性（如饱和和对比度增益控制）。因此，我们提出，至少在LGN之前，新旧世界猴视觉系统的时间特性是相似的。然而，存在一些数量上的差异，表明在LGN的突触传递阶段发生了反应改变。最重要的是对较高时间频率反应的衰减以及小细胞和大细胞反应性之间较小的差异。还测量了细胞对方波调制的反应，并与线性系统分析的预测结果进行了比较。线性系统分析对方波调制给出了合理的预测反应，但这些预测比视网膜神经节细胞的预测要差，表明在LGN的突触转换处引入了额外的非线性。
