Tauchi M, Tanaka I
Jpn J Physiol. 1987;37(2):169-81. doi: 10.2170/jjphysiol.37.169.
Electrical responses to light flashes were recorded from single red rods in dark-adapted retinas of the bullfrog, Rana catesbeiana. When the flashes were less than or equal to 50 ms in duration, plots of the peak amplitude of the responses as a function of log stimulus intensity were found to be parallel, and the stimulus intensity and duration required to elicit criterion-amplitude responses showed a linear relation with a negative unit slope. Furthermore the waveforms of equal-amplitude responses to flashes of different intensities and durations were superimposable. With increases in the stimulus duration beyond 50 ms, however, the slopes of the response-log intensity curves for the higher stimulus intensities decreased, the slope of curves describing the intensity required to elicit criterion responses became less negative, and the responses of the rods decayed more slowly. These results indicate that within 50 ms after the onset of flash stimuli, the effect of incident photons summate linearly to evoke rod responses of certain sub-saturating amplitudes when assessed in terms of the peak response amplitude as well as the response waveform.
在牛蛙（Rana catesbeiana）暗适应视网膜的单个红色视杆细胞中记录了对闪光的电反应。当闪光持续时间小于或等于50毫秒时，发现反应的峰值幅度与对数刺激强度的关系图是平行的，并且引发标准幅度反应所需的刺激强度和持续时间呈负单位斜率的线性关系。此外，对不同强度和持续时间闪光的等幅度反应的波形是可叠加的。然而，随着刺激持续时间增加到超过50毫秒，较高刺激强度下反应-对数强度曲线的斜率降低，描述引发标准反应所需强度的曲线斜率变得不那么负，并且视杆细胞的反应衰减得更慢。这些结果表明，在闪光刺激开始后的50毫秒内，当根据峰值反应幅度以及反应波形进行评估时，入射光子的效应线性累加以引发具有一定亚饱和幅度的视杆细胞反应。
