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Updated: Jun 8, 2026

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents
Published on: January 24, 2013
Rest-activity cycle and melatonin rhythm in blind free-runners have similar periods
Abstract:
In the absence of the entraining light-dark cycle, most totally blind humans free-run, albeit with relative coordination to nonphotic zeitgebers. Such blind free-runners (BFRs) often attempt to maintain a 24-h sleep-wake schedule and consequently suffer from recurrent sleep disruption and daytime somnolence. This study was conducted to determine the periods of the free-running melatonin rhythm and of the rest-activity cycle in 16 BFRs. It was found that the non-24-h component of the rest-activity rhythm correlated with the observed period of the circadian pacemaker.
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