Abe H, Rusak B
Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada.
Am J Physiol. 1992 Jul;263(1 Pt 2):R116-24. doi: 10.1152/ajpregu.1992.263.1.R116.
Activity rhythms were recorded from hamsters in three conditions: during timed feedings of an attractive diet with free access to regular food, during restriction to 70% of normal food consumption, and during moderate food deprivation with limited temporal access to an attractive diet. An attractive diet given to intact animals did not induce anticipatory activity or entrainment, but damage to the suprachiasmatic nuclei (SCN) led to the development of anticipatory activity. Food restriction to 70% of normal intake led to anticipatory components in some intact animals, without entraining the dominant circadian pacemaker. The combination of a palatable diet and food restriction led to anticipatory activity before the daily feeding times and entrainment of a previously free-running circadian rhythm in some animals. Ablation of the SCN did not eliminate anticipatory activity in experimental animals, but did eliminate the free-running component of the rhythms. These results indicate that hamsters have a mechanism separate from the SCN that can anticipate daily feeding times, as rats do, and that they may show entrainment of the SCN-based pacemaker to such feeding schedules.
在定时投喂美味食物且可自由获取常规食物时、在食物摄入量限制为正常食量的70%时，以及在适度食物剥夺且在有限时间内可获取美味食物时。给完整动物投喂美味食物不会诱导预期活动或产生同步化，但视交叉上核（SCN）受损会导致预期活动的出现。将食物摄入量限制为正常摄入量的70%会在一些完整动物中导致预期成分的出现，但不会使占主导地位的昼夜节律起搏器同步化。美味食物和食物限制相结合会在每日喂食时间之前导致预期活动，并使一些动物先前自由运行的昼夜节律产生同步化。切除SCN并未消除实验动物的预期活动，但确实消除了节律的自由运行成分。这些结果表明，仓鼠具有一种独立于SCN的机制，该机制能够像大鼠一样预测每日喂食时间，并且它们可能会使基于SCN的起搏器与这种喂食时间表产生同步化。
