Fang, Zhiwu, Scott H. Carlson, Ning Peng, and J. Michael Wyss. Circadian rhythm of plasma sodium is disrupted in spontaneously hypertensive rats fed a high-NaCl diet. Am J Physiol Regulatory Integrative Comp Physiol 278: R1490–R1495, 2000.—High-NaCl diets elevate arterial pressure in NaCl-sensitive individuals, and increases in plasma sodium may trigger this effect. The present study tests the ...

BACKGROUND The study objective was to clarify the descriptive characteristics of circadian rhythm abnormalities of wrist activity of the institutionalized elderly with dementia. METHODS We studied 82 elderly persons with dementia who were institutionalized in a long-term medical care facility. The ambulatory continuous monitoring of their wrist activity was conducted for 7 days at 1-minute in...

Aging alters many aspects of circadian rhythmicity, including responsivity to phase-shifting stimuli and the amplitude of the rhythm of melatonin secretion. As melatonin is both an output from and an input to the circadian clock, we hypothesized that the decreased melatonin levels exhibited by old hamsters may adversely impact the circadian system as a whole. We enhanced the diurnal rhythm of m...

INTRODUCTION The human circadian timing system generates multiple circadian rhythms. One of the characteristics of a rhythm is the phase. The circadian phase could be defined as the time at which the circadian rhythm of a variable reaches a particular state (Van Dongen, 1998). Substantial inter-individual differences in the circadian phase of several variables have been observed (Foret, 1982; K...

It is important to realize that characterization of the circadian rhythm patterns of seizure occurrence can implicate in diagnosis and treatment of selected types of epilepsy. Evidence suggests a role for the suprachiasmatic nucleus (SCN) circuits in overall circadian rhythm and seizure susceptibility both in animals and humans. Thus, we conclude that SCN circuits may exert modifying effects on...

Background: spacecrafts rotate around the Earth every 90 minutes, so the 24-hour cycle turns to 90 minutes. Retinoic acid, an active metabolite of vitamin A, plays a role in regulating the circadian rhythm and its deficiency can impair the biological clock function and consequently impair the circadian rhythm of locomotor activity. The goal of the study was to assay the effects of simulated spa...

The clock regulating mammalian circadian rhythmicity resides in the suprachiasmatic nucleus. The intergeniculate leaflet, a major component of the subcortical visual system, has been shown to be essential for certain aspects of circadian rhythm regulation. We now report that midbrain visual nuclei afferent to the intergeniculate leaflet are also components of the hamster circadian rhythm system...

Circadian rhythm is defined as a 24-hour biological oscillation, which persists even without any external cues but also can be re-entrained by various environmental cues. One of the widely accepted circadian rhythm behavioral experiment is measuring the wheel-running activity (WRA) of rodents. However, the price for commercially available WRA recording system is not easily affordable for resear...

INTRODUCTION The hormone melatonin regulates the sleep and this pineal hormone is synthesized in the organism from the amino acid tryptophan. It is known that breast-fed babies have better sleep patterns and a better entrained sleep/wake cycle than bottle-fed babies (adapted formula). OBJECTIVE To compare the circadian rhythm of 6-sulfatoxymelatonin (aMT6s)--the metabolite of melatonin excret...