Bassi C J, Powers M K
Department of Psychology, Vanderbilt University, Nashville, Tennessee.
Invest Ophthalmol Vis Sci. 1987 Nov;28(11):1811-5.
To determine whether rod-mediated vision in goldfish is regulated by a circadian clock, absolute threshold was measured psychophysically in animals maintained in constant darkness. Responses were recorded approximately every 4 hr to a diffuse 532 nm stimulus, 5 sec in duration, with no background light present. Visual threshold tended to be lowest at the time of transition from light to dark, as experienced by the fish before it was placed in constant darkness. Threshold tended to be highest at the time of transition from dark to light. The average peak-to-trough fluctuation for five fish was 0.5 log unit in amplitude, and its period was about 24 hr. The results show that the rhythm in visual threshold can still be detected after 7 days of darkness, and that it can be entrained to a new light-dark cycle. These properties are characteristic of regulation by a circadian oscillator.
为了确定金鱼中视杆介导的视觉是否受昼夜节律时钟调节，在持续黑暗环境中饲养的动物身上通过心理物理学方法测量了绝对阈值。大约每4小时记录一次对持续5秒的532nm漫射刺激的反应，不存在背景光。视觉阈值在从明到暗的转变时刻往往最低，这是鱼在被置于持续黑暗之前所经历的。阈值在从暗到明的转变时刻往往最高。五条鱼的平均峰谷波动幅度为0.5对数单位，其周期约为24小时。结果表明，在黑暗7天后仍能检测到视觉阈值的节律，并且它可以被调整到新的明暗周期。这些特性是昼夜节律振荡器调节的特征。
