Van der Zee E A, Jansen K, Gerkema M P
Zoological Laboratory, Biological Centre, University of Groningen, Kerklaan 30, 9751 NN, Haren, Netherlands.
Brain Res. 1999 Jan 23;816(2):572-9. doi: 10.1016/s0006-8993(98)01239-6.
Aging leads to a decrease in circadian organization of behavior. Whether this general observation is related to the finding that in older subjects the arginine-vasopressin (AVP) system in the suprachiasmatic nucleus (SCN) has deteriorated is an unsolved question. Here we assessed circadian organization of running wheel behavior and numbers of AVP cells in the SCN of old voles (n=12, 11. 5 months of age) and compared the results with data from young voles (n=16, 4.5 months of age). A third of the young voles, but three-quarter of the old voles lost circadian rhythmicity. Analysis of daily onset to onset periodicity of running wheel activity at the age of 5 and 10 months in individual voles revealed a significant loss of precision of circadian rhythmicity at the higher age. The number of AVP cells in the SCN of old voles decreased substantially, over 78% compared to young voles in general. AVP cell numbers, however, cannot be directly correlated with the state of rhythmicity in old voles; in one of the three circadian rhythmic old voles the SCN contained the least AVP cells. This study does not support the idea of a causal relationship between aging induced reduction in AVP cells in the SCN and the presence of circadian rhythmicity in behavior.
衰老导致行为的昼夜节律组织能力下降。这种普遍观察结果是否与以下发现相关，即在老年个体中视交叉上核（SCN）中的精氨酸加压素（AVP）系统已经退化，这是一个尚未解决的问题。在这里，我们评估了老年田鼠（n = 12，11.5月龄）SCN中AVP细胞数量和转轮行为的昼夜节律组织，并将结果与年轻田鼠（n = 16，4.5月龄）的数据进行比较。三分之一的年轻田鼠，但四分之三的老年田鼠失去了昼夜节律。对个体田鼠在5个月和10个月大时转轮活动的每日起始到起始周期分析显示，在较高年龄时昼夜节律的精确性显著丧失。老年田鼠SCN中AVP细胞的数量大幅减少，总体上比年轻田鼠减少了78%以上。然而，AVP细胞数量与老年田鼠的节律状态没有直接关联；在三只具有昼夜节律的老年田鼠中，有一只的SCN中AVP细胞最少。这项研究不支持SCN中AVP细胞因衰老而减少与行为中昼夜节律的存在之间存在因果关系的观点。
