Sakai H M, Naka K
Department of Ophthalmology, New York University Medical Center, New York 10016, USA.
J Gen Physiol. 1995 Jun;105(6):795-814. doi: 10.1085/jgp.105.6.795.
Responses from catfish retinal ganglion cells were evoked by a spot or an annulus of light and were analyzed by a procedure identical to the one used previously to study catfish amacrine cells (Sakai H. M., and K.-I. Naka, 1992. Journal of Neurophysiology. 67:430-442.). In two-input white-noise experiments, a response evoked by simultaneous stimulation of the center and surround was decomposed into the components generated by the center and surround through a process of cross-correlation. The center and surround responses were also decomposed into their linear and nonlinear components so that the response dynamics of the linear and nonlinear components could be measured. We found that the concentric organization of the receptive field was determined by linear components, i.e., the first-order kernels generated by the center and surround were of opposite polarity. Both the center and surround generated second-order kernels with similar signatures, i.e., the second-order components formed a monotonic receptive field. The peak response time of the first- and second-order kernels from the surround was longer by approximately 20 ms than that of the center. Except for the DC potential present in the intracellular responses, almost identical first- and second-order kernels for the center and surround were obtained from both the intracellular response and spike discharges. Thus, information on concentric organization of a receptive field is translated into spike discharges with little loss of information. A train of spike discharges carries, simultaneously, at least four kinds of information: two linear and two nonlinear components, which originate in the receptive field center and the surround. A spike train is not a simple signaling device but is a carrier of complex and multiple signals. Victor, J. D., and R. M. Shapley (1979. Journal of General Physiology. 74:671-687.) discovered similarly that, in the cat retina, static second-order nonlinearity is encoded into spike trains. Results obtained in this study support the thesis that signals generated by the preganglionic cells are translated into spike discharges without major modification and that those signals can be recovered from the spike trains (Sakuranaga, M., Y. Ando, and K.-I. Naka. 1987. Journal of General Physiology. 90:229-259.; Korenberg, M. J., H. M. Sakai, and K.-I. Naka. 1989. Journal of Neurophysiology. 61:1110-1120.). Current injection studies have shown that such signal transmission is possible (Sakai, H. M., and K.-I. Naka, 1988a. Journal of Neurophysiology. 60:1549-1567.; 1990. Journal of Neurophysiology. 63:105-119.).
鲶鱼视网膜神经节细胞的反应由光点或光环诱发，并通过与先前用于研究鲶鱼无长突细胞的程序相同的方法进行分析（Sakai H. M.和K.-I. Naka，1992年。《神经生理学杂志》。67:430 - 442）。在双输入白噪声实验中，通过互相关过程将同时刺激中心和周边所诱发的反应分解为由中心和周边产生的成分。中心和周边反应也被分解为它们的线性和非线性成分，以便能够测量线性和非线性成分的反应动力学。我们发现，感受野的同心组织由线性成分决定，即由中心和周边产生的一阶核具有相反的极性。中心和周边都产生具有相似特征的二阶核，即二阶成分形成一个单调的感受野。周边的一阶和二阶核的峰值反应时间比中心的长约20毫秒。除了细胞内反应中存在的直流电位外，从细胞内反应和动作电位发放中获得的中心和周边的一阶和二阶核几乎相同。因此，关于感受野同心组织的信息被转化为动作电位发放，信息损失很小。一串动作电位发放同时携带至少四种信息：两种线性和两种非线性成分，它们分别起源于感受野的中心和周边。一个动作电位序列不是一个简单的信号装置，而是一个复杂和多种信号的载体。Victor, J. D.和R. M. Shapley（1979年。《普通生理学杂志》。74:671 - 687）同样发现，在猫视网膜中，静态二阶非线性被编码到动作电位序列中。本研究获得的结果支持这样的论点，即节前细胞产生的信号被转化为动作电位发放而没有重大改变，并且这些信号可以从动作电位序列中恢复（Sakuranaga, M.、Y. Ando和K.-I. Naka。1987年。《普通生理学杂志》。90:229 - 259；Korenberg, M. J.、H. M. Sakai和K.-I. Naka。1989年。《神经生理学杂志》。61:1110 - 1120）。电流注入研究表明这种信号传递是可能的（Sakai, H. M.和K.-I. Naka，1988a。《神经生理学杂志》。60:1549 - 1567；1990年。《神经生理学杂志》。63:105 - 119）。
