Hofman M A, Swaab D F
Netherlands Institute for Brain Research Graduate School of Neurosciences, Amsterdam.
Brain Res. 1994 Jul 18;651(1-2):134-42. doi: 10.1016/0006-8993(94)90689-0.
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is implicated in the temporal organization of circadian rhythms in a variety of physiological, endocrine and behavioral processes. There is a great deal of evidence indicating that aging is characterized by a progressive deterioration of circadian timekeeping. The present study was aimed at investigating whether there are age-related changes in circadian rhythmicity of the vasopressin (VP)-producing neurons in the human SCN. To that end brains obtained at autopsy of 39 subjects, ranging in age from 6 to 91 years, were studied. Subjects were divided into two age groups, viz. 'young subjects' (up to 50 years) and 'elderly subjects' (over 50 years). It is shown that the number of VP-immunoreactive neurons in the human SCN exhibits a marked diurnal oscillation in young, but not in elderly, people. Whereas in young subjects low VP-immunoreactive neuron numbers were found during the night period (22:00-06:00 h) and peak values during the early morning (06:00-10:00 h), the SCN of elderly people showed a reduced amplitude and a tendency for a reversed diurnal pattern with high instead of low values during the night. The findings suggest that the VP synthesis of the human SCN exhibits a circadian rhythm that is disrupted later in life.
下丘脑前部的视交叉上核（SCN）参与多种生理、内分泌和行为过程中昼夜节律的时间组织。有大量证据表明，衰老的特征是昼夜节律的逐渐衰退。本研究旨在调查人类SCN中产生血管加压素（VP）的神经元的昼夜节律是否存在与年龄相关的变化。为此，研究了39名年龄在6至91岁之间的受试者尸检时获得的大脑。受试者被分为两个年龄组，即“年轻受试者”（50岁及以下）和“老年受试者”（50岁以上）。结果表明，人类SCN中VP免疫反应性神经元的数量在年轻人中表现出明显的昼夜振荡，而在老年人中则没有。在年轻受试者中，夜间（22:00-06:00）VP免疫反应性神经元数量较低，清晨（06:00-10:00）达到峰值，而老年人的SCN振幅减小，夜间出现高值而非低值的昼夜模式逆转趋势。这些发现表明，人类SCN的VP合成表现出昼夜节律，且在生命后期被破坏。
