鲤属鱼L-型外水平细胞所接收的锥细胞信号

在保持正常血液循环的眼杯标本上,用细胞内微电极技术记录了 L-型外水平细胞(LHC)的反应,并且用颜色光适应方法分析了它所接收的锥细胞输入。结果表明,在白光明适应条件下,LHC 依然接收红敏和绿敏锥细胞的输入,但两者的相对贡献与暗视时有所不同。用蓝适应光可以基本上分离红敏锥细胞的信号;而在红色背景光下,绿敏锥细胞主导了反应的上升相和撤光后回跳相(off-rebound),但在反应平台处却是红敏锥细胞的信号作出主要贡献,表明不同的锥细胞信号显然有不同的潜伏期和时程。

CONE INPUT SIGNALS TO L-TYPE EXTERNAL HORIZONTAL CELLS OF THE CYPRINID RETINA

The types of cones converging onto L-type external horizontal cells(LHCs)were studied intracellularly in cyprinid fish eye-cup preparations having intactand normal circulation and analysed using selective chromatic adaptation.Com-pared to the dark-adapted state,red-sensitive cones provided a relatively largercontribution to LHCs in the presence of a white light background.Adapted toblue(451 nm)background,spectral sensitivities of LHCs were independent of responsephases selected for determination and agreed well with that of red-sensitive cones.This indicated that the input from red-sensitive cones might be isolated under thiscondition.Under strong red(655 nm)background,the input from green-sensitivecones dominated the initial rising phase and the off-rebound of the response,whileinput from red-sensitive cones provided contribution mainly to the plateau.Itis thus inferred that inputs from red-sensitive and green-sensitive cones to LHCshave different latencies and time courses.