Efferent control of temporal response properties of the Limulus lateral eye.
Efferent control of temporal response properties of the Limulus lateral eye.
复制标题
鲎外侧眼的时间响应特性的传出控制。
DOI：
10.1085/jgp.95.2.229
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
BarlowJr,RB
中科院分区：
文献类型：
--
作者：
Batra,R;BarlowJr,RB
鲎侧眼的敏感性表现出明显的昼夜节律。在夜间，大脑中的昼夜节律振荡器激活视神经中的传出纤维，引起视网膜细胞的生理和解剖特征的多种变化。这些变化使视网膜的灵敏度增加了大约五个数量级。我们研究了这种视网膜敏感性的增加是否伴随着视网膜处理时间信息能力的变化。我们通过记录单个感受器（小眼）视神经纤维对正弦调制光的反应来测量其频率传递特性（FTC）。我们首先测量FTC在不太敏感的白天状态，然后在转换后的视网膜更敏感的夜间状态，通过电刺激传出纤维。这些纤维的激活使FTC的峰值向低频移动，并降低了低频分支的斜率。这些变化降低了眼睛检测光强度快速变化的能力，但增强了其检测微弱闪光的能力。显然，鲎牺牲了时间分辨率，以提高夜间的视觉灵敏度。
The sensitivity of the Limulus lateral eye exhibits a pronounced circadian rhythm. At night a circadian oscillator in the brain activates efferent fibers in the optic nerve, inducing multiple changes in the physiological and anatomical characteristics of retinal cells. These changes increase the sensitivity of the retina by about five orders of magnitude. We investigated whether this increase in retinal sensitivity is accompanied by changes in the ability of the retina to process temporal information. We measured the frequency transfer characteristic (FTC) of single receptors (ommatidia) by recording the response of their optic nerve fibers to sinusoidally modulated light. We first measured the FTC in the less sensitive daytime state and then after converting the retina to the more sensitive nighttime state by electrical stimulation of the efferent fibers. The activation of these fibers shifted the peak of the FTC to lower frequencies and reduced the slope of the low-frequency limb. These changes reduce the eye's ability to detect rapid changes in light intensity but enhance its ability to detect dim flashes of light. Apparently Limulus sacrifices temporal resolution for increased visual sensitivity at night.