Effects of circadian phase and melatonin injection on anxiety-like behavior in nocturnal and diurnal rodents

2013 ◽  
Vol 30 (6) ◽  
pp. 828-836 ◽  
Author(s):  
Carmel Bilu ◽  
Noga Kronfeld-Schor
Author(s):  
Sarah Bogen ◽  
Tanja Legenbauer ◽  
Stephanie Gest ◽  
Martin Holtmann

Abstract. Objective: In recent years, bright light therapy (BLT) has been used to treat depression and to stabilize circadian rhythms. In this study we evaluated whether it is also helpful for comorbid symptoms of affective and behavioral dysregulation in depressive inpatients. Method: This article reports a secondary analysis comparing two subgroups of depressive participants with comorbid affective and behavioral dysregulation, captured with the dysregulation-profile of the Strengths and Difficulties Questionnaire (SDQ-DP; n = 16 vs. n = 11). Participants were randomly allocated to active BLT (10,000 lux) or control BLT (approx. 100 lux), and received 45 minutes of BLT for 2 weeks. SDQ-DP scores, sleep parameters, and circadian preference were assessed at baseline, after the intervention, and 3 weeks later. Results: No direct effects on SDQ-DP scores were observed. Sleep improved in both conditions. Only in the active BLT condition was a circadian phase advance found. Correlation and regression analyses indicated an indirect, circadian effect for improved SDQ-DP scores. Conclusions: The data of this pilot trial should be considered preliminary and merely descriptive. Further research is warranted.



2021 ◽  
Vol 3 (1) ◽  
pp. 181-188
Author(s):  
Peter Bracke ◽  
Eowyn Van de Putte ◽  
Wouter R. Ryckaert

Dose-response curves for circadian phase shift and melatonin suppression in relation to white or monochromatic nighttime illumination can be scaled to melanopic weighed illumination for normally constricted pupils, which makes them easier to interpret and compare. This is helpful for a practical applications.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A36-A36
Author(s):  
Leah Callovini ◽  
Gaby Gubka ◽  
Candace Mayer ◽  
Darlynn Rojo-Wissar ◽  
David Glickenstein ◽  
...  

Abstract Introduction Few studies have examined circadian phase after job loss, an event that upends daily routine. It is common that a daily routine begins with the consumption of breakfast, and breakfast behavior may contribute to health status in adults. Therefore, we sought to examine whether a later midpoint of sleep was associated with breakfast skipping among adults whose schedules were no longer dictated by employment. Methods Data were obtained from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study. The sample of 155 participants had involuntarily lost their jobs in the last 90 days. Both cross-sectional and 18-month longitudinal analyses assessed the relationship between sleep midpoint after job loss and current and later breakfast skipping. Assessment periods were 14 days. Sleep was measured via actigraphy, and breakfast skipping was measured via daily diary (1 = had breakfast; 0 = did not have breakfast). The midpoint of sleep was calculated as the circular center based on actigraphy sleep onset and offset times. Results The midpoint of sleep at baseline was negatively associated with breakfast consumption at baseline (B = -.09, SE = .02, p = .000). Also, a later midpoint was associated with breakfast skipping over the next 18 months (estimate = -.08; SE = .02; p = .000). Prospective findings remained significant when adjusting for gender, ethnicity, age, perceived stress, body mass index (BMI), education, and reemployment over time. Education (estimate = 14.26, SE = 6.23, p < .05) and BMI (estimate = -.51, SE = .25, p < .05) were the only significant covariates. No other sleep indices predicted breakfast behavior cross-sectionally or prospectively. Conclusion Consistent with research in adolescents, unemployed adults with a later circadian phase are more likely to skip breakfast more often. Breakfast skipping was also associated with higher BMI. Taken together, these findings provide support for the future testing of sleep/wake scheduling interventions to modify breakfast skipping and potentially mitigate weight gain after job loss. Support (if any) #1R01HL117995-01A1


1996 ◽  
Vol 270 (4) ◽  
pp. R830-R837 ◽  
Author(s):  
M. Lancel ◽  
S. Mathias ◽  
J. Faulhaber ◽  
T. Schiffelholz

The cytokine interleukin (IL)-1 is a key mediator of the somnogenic response to immune challenge. In this vehicle-controlled study we evaluated circadian interference with the sleep-promoting effects of IL-1 beta. In two randomized experiments, rats were injected intracerebroventricularly with 5 ng IL-1 beta either at the beginning of the rest phase or at the beginning of the activity phase. Recordings were made during the 24 h preceding the injections (baseline) and during the first 12 postinjection hours. To avoid masking effects of light, the rats were maintained under a skeleton photoperiod during recording. During both the rest and activity phase, IL-1 beta induced fever and initially promoted non-rapid eye movement sleep (REMS). The effect of IL-1 beta on the duration of non-REMS and electroencephalogram (EEG) power densities within non-REMS was related to circadian phase. During the rest phase, IL-1 beta resulted in a minor increase in non-REMS duration but a prominent enhancement in EEG activity in the delta (0.5-4 Hz) and most other frequency bands. During the activity phase, IL-1 beta evoked a larger increase in the duration of non-REMS but hardly affected EEG activity within this state. Thus the effects of IL-1 beta on non-REMS are strongly influenced by diurnal phase. The alterations in EEG power density are in contrast to those elicited by sleep deprivation, which are largely independent of time of day. It is concluded that IL-1 beta activates EEG regulatory mechanisms mediated by processes that depend on circadian phase.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2514
Author(s):  
Santiago Andrés Plano ◽  
Fernando Martín Baidanoff ◽  
Laura Lucía Trebucq ◽  
Sebastián Ángel Suarez ◽  
Fabio Doctorovich ◽  
...  

The circadian clock at the hypothalamic suprachiasmatic nucleus (SCN) entrains output rhythms to 24-h light cycles. To entrain by phase-advances, light signaling at the end of subjective night (circadian time 18, CT18) requires free radical nitric oxide (NO•) binding to soluble guanylate cyclase (sGC) heme group, activating the cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG). Phase-delays at CT14 seem to be independent of NO•, whose redox-related species were yet to be investigated. Here, the one-electron reduction of NO• nitroxyl was pharmacologically delivered by Angeli’s salt (AS) donor to assess its modulation on phase-resetting of locomotor rhythms in hamsters. Intracerebroventricular AS generated nitroxyl at the SCN, promoting phase-delays at CT14, but potentiated light-induced phase-advances at CT18. Glutathione/glutathione disulfide (GSH/GSSG) couple measured in SCN homogenates showed higher values at CT14 (i.e., more reduced) than at CT18 (oxidized). In addition, administration of antioxidants N-acetylcysteine (NAC) and GSH induced delays per se at CT14 but did not affect light-induced advances at CT18. Thus, the relative of NO• nitroxyl generates phase-delays in a reductive SCN environment, while an oxidative favors photic-advances. These data suggest that circadian phase-locking mechanisms should include redox SCN environment, generating relatives of NO•, as well as coupling with the molecular oscillator.


2008 ◽  
Vol 64 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Floor van Oosterhout ◽  
Stephan Michel ◽  
Tom Deboer ◽  
Thijs Houben ◽  
Rob C. G. van de Ven ◽  
...  

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