Alterations in circadian rhythmicity of the vasopressin-producing neurons of the human suprachiasmatic nucleus (SCN) with aging.
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.
Hofman
M A
MA
Netherlands Institute for Brain Research Graduate School of Neurosciences, Amsterdam.
Swaab
D F
DF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism / Q000502:physiology*; D002648:Child; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000378:metabolism / Q000502:physiology*; D014667:Vasopressins / Q000378:metabolism*
D014667:Vasopressins