scholarly journals Effects of Night Illumination on Behavior, Body Mass and Learning in Male Zebra Finches

Birds ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 381-394
Author(s):  
Abhilash Prabhat ◽  
Mayank Kumar ◽  
Ashwani Kumar ◽  
Vinod Kumar ◽  
Sanjay K. Bhardwaj
Keyword(s):  
Body Mass ◽  
Memory Performance ◽  
Sleep Onset ◽  
Learning Task ◽  
Zebra Finches ◽  
Light At Night ◽  
Sleep Behavior ◽  
Novel Object ◽  
Behavioral Rhythm ◽  
Dim Light

An increase in artificial night lighting has blurred the boundaries of day and night and transformed the natural day-night environment with alteration in the temporal niche of the animals. Male zebra finches were exposed to a dim light at night (dLAN) protocol (Light: dLAN, 12L = 200 lux: 12dLAN = 5 lux) with controls on darkness at night (Light: dark, 12L = 200 lux: 12D = 0 lux) for six weeks. We assayed sleep-wake, daily behaviors, mood, and cognition, as well as changes in physiological parameters. Dim light at night increased sleep frequency, delayed sleep onset, advanced awakening latency, and caused a reduction in total sleep duration. dLAN birds did not associate (physical association) with novel object and birds spent significantly lesser time on perch with novel object as compared to LD. In colour learning task, night illuminated birds took more time to learn and made more error, compared to LD. dLAN significantly altered the 24-h daily behavioral rhythm (amplitude and acrophase) of feeding, drinking, preening, and perch-hopping behavior. In particular, birds extended their feeding hours in the nighttime under dLAN, with no difference in total food intake. Birds under dLAN increased fattening and hence significantly increased body mass. Our results show that dim light at night altered feeding rhythm, caused decrease in sleep behavior, and negatively affected learning and memory performance in male zebra finches.

scholarly journals Circadian tau differences and rhythm associations in delayed sleep–wake phase disorder and sighted non-24-hour sleep–wake rhythm disorder

SLEEP ◽  
2020 ◽  
Author(s):  
Gorica Micic ◽  
Nicole Lovato ◽  
Sally A Ferguson ◽  
Helen J Burgess ◽  
Leon Lack
Keyword(s):  
Circadian Rhythm ◽  
Core Body Temperature ◽  
Sleep Onset ◽  
Phase Relationship ◽  
Biological Rhythms ◽  
Circadian Phase ◽  
Behavioral Rhythm ◽  
Rhythm Disorder ◽  
Dim Light ◽  
Delayed Sleep

Abstract Study Objectives We investigated biological and behavioral rhythm period lengths (i.e. taus) of delayed sleep–wake phase disorder (DSWPD) and non-24-hour sleep–wake rhythm disorder (N24SWD). Based on circadian phase timing (temperature and dim light melatonin onset), DSWPD participants were dichotomized into a circadian-delayed and a circadian non-delayed group to investigate etiological differences. Methods Participants with DSWPD (n = 26, 17 m, age: 21.85 ± 4.97 years), full-sighted N24SWD (n = 4, 3 m, age: 25.75 ± 4.99 years) and 18 controls (10 m, age: 23.72 ± 5.10 years) participated in an 80-h modified constant routine. An ultradian protocol of 1-h “days” in dim light, controlled conditions alternated 20-min sleep/dark periods with 40-min enforced wakefulness/light. Subjective sleepiness ratings were recorded prior to every sleep/dark opportunity and median reaction time (vigilance) was measured hourly. Obtained sleep (sleep propensity) was derived from 20-min sleep/dark opportunities to quantify hourly objective sleepiness. Hourly core body temperature was recorded, and salivary melatonin assayed to measure endogenous circadian rhythms. Rhythm data were curved using the two-component cosine model. Results Patients with DSWPD and N24SWD had significantly longer melatonin and temperature taus compared to controls. Circadian non-delayed DSWPD had normally timed temperature and melatonin rhythms but were typically sleeping at relatively late circadian phases compared to those with circadian-delayed DSWPD. Conclusions People with DSWPD and N24SWD exhibit significantly longer biological circadian rhythm period lengths compared to controls. Approximately half of those diagnosed with DSWPD do not have abnormally delayed circadian rhythm timings suggesting abnormal phase relationship between biological rhythms and behavioral sleep period or potentially conditioned sleep-onset insomnia.

Acute dim light at night increases body mass, alters metabolism, and shifts core body temperature circadian rhythms

2014 ◽  
Vol 31 (8) ◽  
pp. 917-925 ◽  
Author(s):  
Jeremy C. Borniger ◽  
Santosh K. Maurya ◽  
Muthu Periasamy ◽  
Randy J. Nelson
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Body Mass ◽  
Core Body Temperature ◽  
Light At Night ◽  
Dim Light ◽  
And Shifts ◽  
Core Body

scholarly journals Dim light at night increases body mass of female mice

2014 ◽  
Vol 32 (4) ◽  
pp. 557-560 ◽  
Author(s):  
Taryn G. Aubrecht ◽  
Richelle Jenkins ◽  
Randy J. Nelson
Keyword(s):  
Body Mass ◽  
Light At Night ◽  
Female Mice ◽  
Dim Light

scholarly journals Hippocampal-dependent learning requires a functional circadian system

2008 ◽  
Vol 105 (40) ◽  
pp. 15593-15598 ◽  
Author(s):  
Norman F. Ruby ◽  
Calvin E. Hwang ◽  
Colin Wessells ◽  
Fabian Fernandez ◽  
Pei Zhang ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Memory Performance ◽  
Memory Function ◽  
Recognition Task ◽  
Learning Task ◽  
Brain Regions ◽  
Circadian System ◽  
Surgical Ablation ◽  
Novel Object ◽  
Dependent Learning

Decades of studies have shown that eliminating circadian rhythms of mammals does not compromise their health or longevity in the laboratory in any obvious way. These observations have raised questions about the functional significance of the mammalian circadian system, but have been difficult to address for lack of an appropriate animal model. Surgical ablation of the suprachiasmatic nucleus (SCN) and clock gene knockouts eliminate rhythms, but also damage adjacent brain regions or cause developmental effects that may impair cognitive or other physiological functions. We developed a method that avoids these problems and eliminates rhythms by noninvasive means in Siberian hamsters (Phodopus sungorus). The present study evaluated cognitive function in arrhythmic animals by using a hippocampal-dependent learning task. Control hamsters exhibited normal circadian modulation of performance in a delayed novel-object recognition task. By contrast, arrhythmic animals could not discriminate a novel object from a familiar one only 20 or 60 min after training. Memory performance was not related to prior sleep history as sleep manipulations had no effect on performance. The GABA antagonist pentylenetetrazol restored learning without restoring circadian rhythms. We conclude that the circadian system is involved in memory function in a manner that is independent of sleep. Circadian influence on learning may be exerted via cyclic GABA output from the SCN to target sites involved in learning. Arrhythmic hamsters may have failed to perform this task because of chronic inhibitory signaling from the SCN that interfered with the plastic mechanisms that encode learning in the hippocampus.

scholarly journals Investigating the Effects of Seizures on Procedural Memory Performance in Patients with Epilepsy

2021 ◽  
Vol 11 (2) ◽  
pp. 261
Author(s):  
Frank J. van Schalkwijk ◽  
Walter R. Gruber ◽  
Laurie A. Miller ◽  
Eugen Trinka ◽  
Yvonne Höller
Keyword(s):  
Temporal Lobe ◽  
Declarative Memory ◽  
Memory Performance ◽  
Total Sample ◽  
Learning Task ◽  
Procedural Memory ◽  
Memory Retention ◽  
Motor Sequence ◽  
Performance Improvements ◽  
Patients With Epilepsy

Memory complaints are frequently reported by patients with epilepsy and are associated with seizure occurrence. Yet, the direct effects of seizures on memory retention are difficult to assess given their unpredictability. Furthermore, previous investigations have predominantly assessed declarative memory. This study evaluated within-subject effects of seizure occurrence on retention and consolidation of a procedural motor sequence learning task in patients with epilepsy undergoing continuous monitoring for five consecutive days. Of the total sample of patients considered for analyses (N = 53, Mage = 32.92 ± 13.80 y, range = 18–66 y; 43% male), 15 patients experienced seizures and were used for within-patient analyses. Within-patient contrasts showed general improvements over seizure-free (day + night) and seizure-affected retention periods. Yet, exploratory within-subject contrasts for patients diagnosed with temporal lobe epilepsy (n = 10) showed that only seizure-free retention periods resulted in significant improvements, as no performance changes were observed following seizure-affected retention. These results indicate general performance improvements and offline consolidation of procedural memory during the day and night. Furthermore, these results suggest the relevance of healthy temporal lobe functioning for successful consolidation of procedural information, as well as the importance of seizure control for effective retention and consolidation of procedural memory.

scholarly journals Divergent Importance of Chronobiological Considerations in High- and Low-dose Melatonin Therapies

Diseases ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Rüdiger Hardeland
Keyword(s):  
Phase Response Curve ◽  
Sleep Onset ◽  
Melatonin Receptors ◽  
Duration Of Action ◽  
Circadian Oscillators ◽  
Protective Actions ◽  
Circadian Control ◽  
Dim Light ◽  
Poor Individual ◽  
Specific Phase

Melatonin has been used preclinically and clinically for different purposes. Some applications are related to readjustment of circadian oscillators, others use doses that exceed the saturation of melatonin receptors MT1 and MT2 and are unsuitable for chronobiological purposes. Conditions are outlined for appropriately applying melatonin as a chronobiotic or for protective actions at elevated levels. Circadian readjustments require doses in the lower mg range, according to receptor affinities. However, this needs consideration of the phase response curve, which contains a silent zone, a delay part, a transition point and an advance part. Notably, the dim light melatonin onset (DLMO) is found in the silent zone. In this specific phase, melatonin can induce sleep onset, but does not shift the circadian master clock. Although sleep onset is also under circadian control, sleep and circadian susceptibility are dissociated at this point. Other limits of soporific effects concern dose, duration of action and poor individual responses. The use of high melatonin doses, up to several hundred mg, for purposes of antioxidative and anti-inflammatory protection, especially in sepsis and viral diseases, have to be seen in the context of melatonin’s tissue levels, its formation in mitochondria, and detoxification of free radicals.

Cnidoscolus aconitifolius-supplemented diet enhanced neurocognition, endogenous antioxidants and cholinergic system and maintains hippocampal neuronal integrity in male Wistar rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olusegun G. Adebayo ◽  
Samuel A. Onasanwo ◽  
Abayomi M. Ajayi ◽  
Wadioni Aduema ◽  
Oyetola T. Oyebanjo ◽  
...  
Keyword(s):  
Cholinergic System ◽  
Water Maze ◽  
Wistar Rats ◽  
Memory Performance ◽  
Novel Object Recognition ◽  
Object Recognition Test ◽  
Novel Object ◽  
Cnidoscolus Aconitifolius ◽  
Novel Object Recognition Test ◽  
Male Wistar Rats

Abstract Objectives Cnidoscolus aconitifolius have been investigated to have abundant phytochemicals. However, study on the effect of Cnidoscolus aconitifolius on neurobehavioral performance when supplemented with diet is lacking. The study is aimed at investigating the memory-enhancing effect of Cnidoscolus aconitifolius-supplemented diet (CAD) using Morris water maze and Novel object recognition test. Methods Ninety male Wistar rats (80–100 g) were fed with CAD (1, 2.5, 5 and 10%) continuously for a period of 4, 8 and 12 weeks respectively. Six animals per group were used for assessment of memory performance (Morris water maze [MWM] and Novel object recognition test [NORT]); afterwards the brain tissues were harvested for malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) estimation. Acetylcholinesterase (AChE) concentration was also determined. Hippocampal architectural change in the neuron was examined using hematoxylin and eosin (H&E) and cresyl fast violet (Nissl) stain. Results Higher percentage of CAD significantly (p<0.05) improve memory performance with time-dependent effects in rats fed with CAD on MMW and NORT. MDA significantly (p<0.05) reduce in 1 and 2.5% CAD groups at 4th weeks and in 2.5 and 5% CAD groups at 8th weeks while GSH concentration significantly (p<0.05) increase at 12th weeks in 2.5 and 10% CAD groups. However, CAT concentration significantly (p<0.05) increase in 2.5, and 5%, CAD groups, 1, 5, and 10% CAD groups and in 5, and 10% CAD groups at 4th, 8th and 12th weeks. AChE significantly (p<0.05) reduce at 4th and 12th weeks. Histological assessment reveals no neuronal and pyramidal degeneration (chromatolysis) at the hippocampal Cornu Ammonis 3 (CA3) region. Conclusions The results suggest that CAD boost memory performance in rats through positive modulation of oxidative stress, cholinergic system and degeneration of hippocampal neurons.

scholarly journals Delayed Lactogenesis II is Associated With Lower Sleep Efficiency and Greater Variation in Nightly Sleep Duration in the Third Trimester

2019 ◽  
Vol 35 (4) ◽  
pp. 713-724
Author(s):  
Theresa Casey ◽  
Hui Sun ◽  
Helen J. Burgess ◽  
Jennifer Crodian ◽  
Shelley Dowden ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Blood Glucose ◽  
Sleep Duration ◽  
Body Mass ◽  
Sleep Disturbances ◽  
Sleep Onset ◽  
Sleep Time ◽  
Sleep Efficiency ◽  
Delayed Onset ◽  
Wrist Actigraphy

Background: Metabolic and hormonal disturbances are associated with sleep disturbances and delayed onset of lactogenesis II. Research aims: The aim of this study was to measure sleep using wrist actigraphy during gestation weeks 22 and 32 to determine if sleep characteristics were associated with blood glucose, body mass index, gestational related disease, delayed onset of lactogenesis II, or work schedule. Methods: Demographic data were collected at study intake from primiparous women who wore a wrist actigraph during gestation weeks 22 ( n = 50) and 32 ( n = 44). Start and end sleep time, total nighttime sleep, sleep efficiency, wake after sleep onset, and sleep fragmentation were measured. Night to night variability was assessed with the root mean square of successive difference. Blood glucose levels, body mass index, and gestational disease data were abstracted from medical charts. Timing of lactogenesis II was determined by survey. Results: Between gestation week 22 and 32, sleep efficiency decreased and fragmentation increased ( p < .05). During gestation week 32, blood glucose was negatively correlated with sleep duration, and positively related to fragmentation ( p < .05). Women who experienced delayed lactogenesis II had lower sleep efficiency and greater fragmentation ( p < .05), and greater night-to-night variability in sleep start and end time, efficiency, and duration during gestation week 32 ( p < .05). Conclusion: Women with better sleep efficiency and more stable nightly sleep time are less likely to experience delayed onset of lactogenesis II. Interventions to improve sleep may improve maternal health and breastfeeding adequacy.

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