Inouye S T
Brain Res. 1984 Mar 5;294(2):263-8. doi: 10.1016/0006-8993(84)91038-2.
To investigate daily variation in responsiveness of the suprachiasmatic nucleus (SCN) to exposure to light, the evoked change in multiple unit activity of the SCN within the retino-hypothalamic island with the retino-hypothalamic tract (RHT) spared, was measured in the rat at 6 h intervals across a 24 h day. It is found that SCN multiple unit discharge rates increase during a 1 h exposure to light which interrupts constant darkness irrespective of the time of day. A non-parametric statistical analysis did not indicate a significant daily variation in light-responsiveness of the SCN. The present results suggest that the phase-dependent shift of the SCN rhythm after a light exposure is induced not by a rhythm in light-responsiveness of the SCN mediated by the RHT, but by a more complicated machinery within the SCN.
为研究视交叉上核（SCN）对光照反应性的日变化，在大鼠中，于24小时内每隔6小时测量一次保留视网膜下丘脑束（RHT）的视网膜下丘脑岛内SCN多单位活动的诱发变化。结果发现，无论一天中的时间如何，在中断持续黑暗的1小时光照期间，SCN多单位放电率都会增加。非参数统计分析未表明SCN对光反应性存在显著的日变化。目前的结果表明，光照后SCN节律的相位依赖性变化不是由RHT介导的SCN对光反应性的节律引起的，而是由SCN内更复杂的机制引起的。
