Sakuranaga M, Ando Y, Naka K
National Institute for Basic Biology, Okazaki, Japan.
J Gen Physiol. 1987 Aug;90(2):229-59. doi: 10.1085/jgp.90.2.229.
Responses were evoked from ganglion cells in catfish and frog retinas by a Gaussian modulation of the mean luminance. An algorithm was devised to decompose intracellularly recorded responses into the slow and spike components and to extract the time of occurrence of a spike discharge. The dynamics of both signals were analyzed in terms of a series of first-through third-order kernels obtained by cross-correlating the slow (analog) or spike (discrete or point process) signals against the white-noise input. We found that, in the catfish, (a) the slow signals were composed mostly of postsynaptic potentials, (b) their linear components reflected the dynamics found in bipolar cells or in the linear response component of type-N (sustained) amacrine cells, and (c) their nonlinear components were similar to those found in either type-N or type-C (transient) amacrine cells. A comparison of the dynamics of slow and spike signals showed that the characteristic linear and nonlinear dynamics of slow signals were encoded into a spike train, which could be recovered through the cross-correlation between the white-noise input and the spike (point process signals. In addition, well-defined spike correlates could predict the observed slow potentials. In the spike discharges from frog ganglion cells, the linear (or first-order) kernels were all inhibitory, whereas the second-order kernels had characteristics of on-off transient excitation. The transient and sustained amacrine cells similar to those found in catfish retina were the sources of the nonlinear excitation. We conclude that bipolar cells and possibly the linear part of the type-N cell response are the source of linear, either excitatory or inhibitory, components of the ganglion cell responses, whereas amacrine cells are the source of the cells' static nonlinearity.
通过对平均亮度进行高斯调制，诱发了鲶鱼和青蛙视网膜神经节细胞的反应。设计了一种算法，将细胞内记录的反应分解为慢波和尖峰成分，并提取尖峰放电的发生时间。根据通过将慢波（模拟）或尖峰（离散或点过程）信号与白噪声输入进行互相关获得的一系列一阶到三阶核，分析了两种信号的动力学。我们发现，在鲶鱼中，（a）慢波信号主要由突触后电位组成，（b）它们的线性成分反映了双极细胞或N型（持续型）无长突细胞的线性反应成分中发现的动力学，并且（c）它们的非线性成分与在N型或C型（瞬变型）无长突细胞中发现的相似。慢波和尖峰信号动力学的比较表明，慢波信号的特征线性和非线性动力学被编码到尖峰序列中，这可以通过白噪声输入与尖峰（点过程信号）之间的互相关来恢复。此外，明确的尖峰相关性可以预测观察到的慢波电位。在青蛙神经节细胞的尖峰放电中，线性（或一阶）核均为抑制性，而二阶核具有开-关瞬态兴奋的特征。类似于在鲶鱼视网膜中发现的瞬态和持续型无长突细胞是非线性兴奋的来源。我们得出结论，双极细胞以及可能N型细胞反应的线性部分是神经节细胞反应线性（兴奋性或抑制性）成分的来源，而无长突细胞是细胞静态非线性的来源。
