Margraf R R, Zlomanczuk P, Liskin L A, Lynch G R
Department of Biology, Wesleyan University, Middletown, CT 06457.
Brain Res. 1991 Mar 22;544(1):42-8. doi: 10.1016/0006-8993(91)90883-w.
The suprachiasmatic nucleus (SCN) of the hypothalamus, as the putative generator of circadian rhythmicity, plays an important role in mammalian photoinduction. To determine if SCN function differs in photo-non-responsive Djungarian hamsters, we defined the pattern of spontaneous neuronal discharge of single cells from SCN slices in vitro of photo-responsive and photo-non-responsive phenotypes. Responsive hamsters exhibited a peak neuronal discharge rate (4.8 +/- 0.5 Hz) during the mid day which gradually attenuated through the late day and early night. In non-responsive hamsters, a similar discharge rate (5.1 +/- 0.5) was maintained through the late day and early night. The delayed decline in spontaneous firing rate of non-responders correlates with their delayed activity onset and delayed nocturnal pineal melatonin pulse. These data support the argument that the absence of photoperiodic adjustments in Phodopus sungorus rests with differences in SCN function.
下丘脑的视交叉上核（SCN）作为昼夜节律的假定发生器，在哺乳动物的光诱导中起着重要作用。为了确定光不敏感的黑线仓鼠的SCN功能是否不同，我们定义了来自光敏感和光不敏感表型的体外SCN切片中单个细胞的自发神经元放电模式。敏感仓鼠在中午表现出神经元放电率峰值（4.8±0.5Hz），该峰值在傍晚和深夜逐渐减弱。在不敏感仓鼠中，在傍晚和深夜维持相似的放电率（5.1±0.5）。无反应者自发放电率的延迟下降与其活动开始延迟和夜间松果体褪黑激素脉冲延迟相关。这些数据支持以下观点，即黑线仓鼠缺乏光周期调节与SCN功能差异有关。
