Two circadian rhythms in the human electroencephalogram during wakefulness

1999 ◽  
Vol 277 (6) ◽  
pp. R1771-R1779 ◽  
Author(s):  
Daniel Aeschbach ◽  
Jeffery R. Matthews ◽  
Teodor T. Postolache ◽  
Michael A. Jackson ◽  
Holly A. Giesen ◽  
...  

The influence of the circadian pacemaker and of the duration of time awake on the electroencephalogram (EEG) was investigated in 19 humans during ∼40 h of sustained wakefulness. Two circadian rhythms in spectral power density were educed. The first rhythm was centered in the theta band (4.25–8.0 Hz) and exhibited a minimum ∼1 h after the onset of melatonin secretion. The second rhythm was centered in the high-frequency alpha band (10.25–13.0 Hz) and exhibited a minimum close to the body temperature minimum. The latter rhythm showed a close temporal association with the rhythms in subjective alertness, plasma melatonin, and body temperature. In addition, increasing time awake was associated with an increase of power density in the 0.25- to 9.0-Hz and 13.25- to 20.0-Hz ranges. It is concluded that the waking EEG undergoes changes that can be attributed to circadian and homeostatic (i.e., sleep-wake dependent) processes. The distinct circadian variations of EEG activity in the theta band and in the high-frequency alpha band may represent electrophysiological correlates of different aspects of the circadian rhythm in arousal.

1984 ◽  
Vol 67 (4) ◽  
pp. 433-437 ◽  
Author(s):  
B. P. O'malley ◽  
A. Richardson ◽  
N. Cook ◽  
S. Swart ◽  
F. D. Rosenthal

1. The diurnal rhythms of body temperature and serum thyrotrophin (TSH) levels in euthyroid individuals behaved inversely to one another. 2. An artificially induced rise in the body temperature of these individuals was accompanied by a fall in serum thyrotrophin levels, the amplitudes of their respective rhythms decreasing simultaneously. 3. There was a marked correlation between the degrees of change in body temperature and circulating thyrotrophin levels respectively during warming. 4. In normal subjects manipulation of the diurnal rhythm of body temperature brings about inverse alterations in the thyrotrophin rhythm.


2021 ◽  
Author(s):  
Michael Jackson Oliveira de Andrade

The physiology of living beings presents oscillations that are known as biological rhythms. The most studied rhythm is called circadian (circa = circa, dies = day), because it varies with a period close to 24h. Most functions of the body have circadian variations, one can mention, for example, metabolism, body temperature, the activity of the nervous system, secretion of hormones such as melatonin and cortisol. Circadian rhythms were also found in human behavior, for example: in sensory activity, motor activity, reaction time, visual perception, auditory perception, time perception, attention, memory, arithmetic calculus, and executive functions. The present work reviews the visual path that participates in the synchronization of circadian rhythms, as well as the evidence that exists about the presence of circadian rhythms in the sensation and visual perception of the human being.


1979 ◽  
Vol 34 (5-6) ◽  
pp. 470-473 ◽  
Author(s):  
A. Johnsson ◽  
W. Engelmann ◽  
W. Klemke ◽  
Aud Tveito Ekse

Abstract The body temperature, activity-rest time, electrolytes of urine samples and mood was measured in two persons during a 19 day period under continuous light conditions in the arctic (vicinity of Ny Ålesund, Svalbard-Spitsbergen). For temperature recording a new thermoprobe and a portable printer was used. Possible week Zeitgeber of the 24 hour day did not synchronize the circadian system, since circadian rhythms of about 26 hours were found. These results open up the pos­ sibility to study effects of drugs on the circadian system of humans under Svalbard conditions.


2019 ◽  
Vol 7 (2) ◽  
pp. 87-107
Author(s):  
J. H. Wearden

The main body of the text presents an English translation of the article by François (1927) on body temperature and time judgements. In summary, François used diathermy, the passage of high-frequency electric current through the body, to change body temperature in three young female participants. Two timing tasks: tapping at a rate that was usually 3/s, and adjusting a variable-speed metronome to a rate judged to be 4/s were used. In general, increases in body temperature shortened the intervals produced, but lengthened duration estimates. The author also discusses (a) the potential use of diurnal variation in body temperature, (b) the use of pulse rate as a predictor of time judgements, and (c) the use of febrile patients. The translation is followed by a short commentary focussing on later studies of body temperature and time judgements, and studies of aspects of heart rate and time judgements.


1990 ◽  
Vol 258 (2) ◽  
pp. R552-R557 ◽  
Author(s):  
M. J. Kluger ◽  
C. A. Conn ◽  
B. Franklin ◽  
R. Freter ◽  
G. D. Abrams

The purpose of these experiments was to test the hypothesis that gut flora influences the body temperature of rodents. Rats and mice were implanted with biotelemetry transmitters that enabled us to record both abdominal temperature and activity for long periods of time. Rats given nonabsorbable antibiotics in their drinking water, which reduced their gut flora, had a marked decrease in both their daytime and nighttime temperatures. Similar results were found with germfree mice. The circadian rhythms in body temperature of germfree and conventionalized mice were not different. However, the body temperatures of the germfree mice were lower than those of the conventionalized mice during both the daytime and nighttime. The decrease in body temperature in the germfree mice was not related to changes in activity. These results support the hypothesis that gut flora has a tonic stimulatory effect on both the daytime and nighttime body temperature of rodents.


2020 ◽  
Vol 16 (1) ◽  
pp. 4-12
Author(s):  
Vandana Garg ◽  
Rohit Dutt

Background: Fever, is known as pyrexia, may occur due to infection, inflammation, or any tissue damage and disease states. Normally, the infected or damaged tissue initiates the enhanced formation of pro-inflammatory mediators like cytokines which further increases the synthesis of prostaglandin E2 (PgE2) near the hypothalamic area and thereby trigger the hypothalamus to elevate the body temperature. Objective: Antipyretics are the agents which reduce the elevated body temperature. The most commonly used antipyretic agent, paracetamol, may be fatal due to its side effects. Methods: In this review paper, Chemical Abstracts, Google Scholar, PubMed, and Science Direct were the sources for the published article to collect information regarding antipyretic activity. Results: This review compiles the antipyretic plants that may be useful to treat fever due to various diseases. Conclusion: These medicinal plants could be good alternatives for traditional allopathic antipyretics.


Author(s):  
Dr.Saurabh Parauha ◽  
Hullur M. A. ◽  
Prashanth A. S.

In Ayurveda, Jwara is not merely the concept of raised body temperature, but as is said in Charaka Samhita, 'Deha- Indriya- Manah- Santap' is the cardinal symptoms of Jwara. This can be defined as the state where the body, mind as well as sense oragans suffer due to the high temperature. Vishamajwara is a type of fever, which is described in all Ayurvedic texts. Charaka mentioned Vishamajwara and Chakrapani have commented on Vishamajwara as Bhutanubanda, Susruta affirmed that Aagantuchhanubhandohi praysho Vishamajware. Madhavakara has also recognised Vishamajwara as Bhutabhishangajanya (infected by microorganism). Vishamajwara is irregular (inconsistent) in it's Arambha (nature of onset commitment), Kriya (action production of symptoms) and Kala (time of appearance) and possesses Anushanga (persistence for long periods). The treatment of this disease depends upon Vegavastha and Avegavastha of Jwara. Various Shodhana and Shamana procedures are mentioned in classics to treat Visham Jwara.


1967 ◽  
Vol 45 (3) ◽  
pp. 321-327 ◽  
Author(s):  
David M. Ogilvie

The effects, on the body temperature of white mice, of repeated short exposures to cold were investigated using two methods of restraint. Animals held in a flattened posture became hypothermic at room temperature, cooled more than five times as fast at −10 °C as mice that could adopt a heat-conserving posture, and continued to cool for some time after they were removed from the cold. With repeated tests, cooling at room temperature decreased, and an improvement in re warming ability was observed. In addition, with lightly restrained mice, the fall in rectal temperature during cold exposure showed a progressive decrease, a phenomenon not observed with severely restrained animals.


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