Control Night Research Articles

Assessment of serum level of corticotropin-releasing factor in primary nocturnal enuresis

Primary nocturnal enuresis is one of the sleep related phenomena characterized by disruption in the relationship between arousal and urination. Corticotropin-releasing factor (CRF) is a neurohormone released from the paraventricular nucleus of the hypothalamus into the median eminence to elicit release of adrenocorticotrophin from the anterior pituitary. It may act to modulate autonomic function and behavior in concert with the endocrine effects. Conflicting animal studies about the role of CRF in micturition, either facilitating or inhibiting, have been raised. It was suggested to be a novel target for treatment of urinary disorders based on the finding that manipulation of CRF in the pontine micturition circuit could affect urodynamic function. The aim was to throw light on the possible role of CRF in primary monosymptomatic nocturnal enuresis by assessing its serum level. Twenty-nine children aged 8-14 years complaining of primary monosymptomatic nocturnal enuresis and 16 age- and sex-matched healthy children with good toilet control day and night were recruited to the study. History taking, clinical examination, and assessment of serum CRF levels in the morning and evening (9 a.m. and 9 p.m.) were carried out for all patients and controls. A positive family history of enuresis was detected in 82.8% of enuretic patients. Serum levels of CRF (both morning and evening) were significantly lower in patients than in controls. Several animal studies suggested that CRF in descending projections from Barrington's nucleus to the lumbosacral parasympathetic neurons is inhibitory to micturition, which supports our results and the assumption that reduction of the evening serum CRF level could have a role in the occurrence of primary monosymptomatic nocturnal enuresis. No significant difference was found between morning and evening CRF serum levels in either cases or controls, which negates our assumption of having a rhythmic pattern of release (figure). No correlations with age were found. According to their history, all our enuretic patients were deep sleepers. Deep sleep and difficult arousal were found to have a major role in primary monosymptomatic nocturnal enuresis. It was proposed that CRF function may allow arousal to occur before micturition to facilitate preparative behaviors. A lower CRF level may explain deep-sleep pattern in children with enuresis. CRF was deficient in our enuretic children, which may draw attention to the possible pathophysiological implications in primary nocturnal enuresis (either at the level of loss of inhibitory effect on micturition or lack of arousal in response to bladder distension). Further proof studies are recommended.

Sleep in intensive care unit: The role of environment

PurposeTo determine if improving intensive care unit (ICU) environment would enhance sleep quality, assessed by polysomnography (PSG), in critically ill mechanically ventilated patients. Materials and methodsRandomized controlled trial, crossover design. The night intervention “quiet routine” protocol was directed toward improving ICU environment between 10pm and 6am. Noise levels during control and intervention nights were recorded. Patients on mechanical ventilation and able to give consent were eligible for the study. We monitored sleep by PSG.The standard (American Association of Sleep Medicine) sleep scoring criteria were insufficient for the assessment of polysomnograms. Modified classification for sleep scoring in critically ill patients, suggested by Watson et al. (Crit Care Med 2013;41:1958-1967), was used. ResultsSound level analysis showed insignificant effect of the intervention on noise reduction (P=.3). The analysis of PSGs revealed that only 53% of the patients had identifiable characteristics of normal sleep, whereas 47% showed only pathologic patterns. ConclusionsCharacteristics of normal sleep were absent in many of the PSG recordings in these critically ill patients. We were not able to further reduce the already existing low noise levels in the ICU and did not find any association between the environmental intervention and the presence of normal sleep characteristics in the PSG.

Effect of Day and Night Desflurane Anaesthesia on Melatonin Levels in Rats.

The aim of this study is to investigate the effect of day and night administration of desflurane anaesthesia on melatonin levels in rats. Twenty-four 15-day-old rats were included in the study and were divided into four groups. The rats were anaesthetised between 19:00-01:00 (night group) and 07:00-13:00 (day group) with 5.7% desflurane concentration in 6 L min-1 100% oxygen. 6 L min-1 oxygen was administered to the control groups. At the end of 6 h of anaesthesia, blood samples were taken, and rats were sacrificed. Blood samples were centrifuged and melatonin levels from plasma samples were measured with radioimmunoassay. There was a statistically significant difference between the groups (p=0.007). Between group day control and group night control there was a statistically significant difference (p=0.042). Further, there was a significant difference between group day control and night desfluran as well (p=0.024). We could not find any difference between other groups. This study showed that 6 hours of 5.7% desflurane anaesthesia during day and night hours did not significantly change melatonin levels.

Automated Overnight Closed-Loop Control Using a Proportional-Integral-Derivative Algorithm with Insulin Feedback in Children and Adolescents with Type 1 Diabetes at Diabetes Camp.

This study determined the feasibility and efficacy of an automated proportional-integral-derivative with insulin feedback (PID-IFB) controller in overnight closed-loop (OCL) control of children and adolescents with type 1 diabetes over multiple days in a diabetes camp setting. The Medtronic (Northridge, CA) Android™ (Google, Mountain View, CA)-based PID-IFB system consists of the Medtronic Minimed Revel™ 2.0 pump and Enlite™ sensor, a control algorithm residing on an Android phone, a translator, and remote monitoring capabilities. An inpatient study was completed for 16 participants to determine feasibility. For the camp study, subjects with type 1 diabetes were randomized to either OCL or sensor-augmented pump therapy (control conditions) per night for up to 6 nights at diabetes camp. During the camp study, 21 subjects completed 50 OCL nights and 52 control nights. Based on intention to treat, the median time spent in range, from 70 to 150 mg/dL, was greater during OCL at 66.4% (n = 55) versus 50.6% (n = 52) during the control period (P = 0.004). A per-protocol analysis allowed for assessment of algorithm performance with the median percentage time in range, 70-150 mg/dL, being 75.5% (n = 37) for OCL versus 47.6% (n = 32) for the control period (P < 0.001). There was less time spent in the hypoglycemic ranges <60 mg/dL and <70 mg/dL during OCL compared with the control period (P = 0.003 and P < 0.001, respectively). The PID-IFB controller is effective in improving time spent in range as well as reducing nocturnal hypoglycemia during the overnight period in children and adolescents with type 1 diabetes in a diabetes camp setting.

Optimal Questions for Sleep in Epidemiological Studies: Comparisons of Subjective and Objective Measures in Laboratory and Field Studies

Epidemiological studies on sleep often use questionnaires, and measurement of validity provides necessary guidance in selection of valid single sleep questions. Twenty-five items assessing different aspects of sleep, including overall sleep quality, specific sleep parameters, nocturnal restoration, and exposure-related questions, were tested. This involved coherence with objective polysomnographic (PSG) laboratory measurements of sleep in 47 participants and application of selected items under field conditions in over 3,000 participants. Items on overall sleep quality correlated significantly with PSG data. For specific sleep parameter questions, tiredness in the morning, time to fall asleep, difficulties to sleep and estimated number of awakenings were correlated to PSG data. Questions asking specifically about the effect of potential sleep disturbances correlated poorly with PSG data, but showed highest effects between environmental exposure (noise and vibration) and control nights in the laboratory and highest correlation with the dose of exposure in the field. In conclusion, healthy participants seem to be able to access their sleep reliably; and sleep questions asking about specific sleep parameters can be recommended for the assessment of sleep.

Inter-individual Differences in the Effects of Aircraft Noise on Sleep Fragmentation.

Environmental noise exposure disturbs sleep and impairs recuperation, and may contribute to the increased risk for (cardiovascular) disease. Noise policy and regulation are usually based on average responses despite potentially large inter-individual differences in the effects of traffic noise on sleep. In this analysis, we investigated what percentage of the total variance in noise-induced awakening reactions can be explained by stable inter-individual differences. We investigated 69 healthy subjects polysomnographically (mean ± standard deviation 40 ± 13 years, range 18-68 years, 32 male) in this randomized, balanced, double-blind, repeated measures laboratory study. This study included one adaptation night, 9 nights with exposure to 40, 80, or 120 road, rail, and/or air traffic noise events (including one noise-free control night), and one recovery night. Mixed-effects models of variance controlling for reaction probability in noise-free control nights, age, sex, number of noise events, and study night showed that 40.5% of the total variance in awakening probability and 52.0% of the total variance in EEG arousal probability were explained by inter-individual differences. If the data set was restricted to nights (4 exposure nights with 80 noise events per night), 46.7% of the total variance in awakening probability and 57.9% of the total variance in EEG arousal probability were explained by inter-individual differences. The results thus demonstrate that, even in this relatively homogeneous, healthy, adult study population, a considerable amount of the variance observed in noise-induced sleep disturbance can be explained by inter-individual differences that cannot be explained by age, gender, or specific study design aspects. It will be important to identify those at higher risk for noise induced sleep disturbance. Furthermore, the custom to base noise policy and legislation on average responses should be re-assessed based on these findings.

Orexin gene transfer into the amygdala suppresses both spontaneous and emotion-induced cataplexy in orexin-knockout mice.

Narcolepsy is a chronic sleep disorder linked to the loss of orexin-producing neurons in the hypothalamus. Cataplexy, a sudden loss of muscle tone during waking, is an important distinguishing symptom of narcolepsy and it is often triggered by strong emotions. The neural circuit underlying cataplexy attacks is not known, but is likely to involve the amygdala, a region implicated in regulating emotions. In mice models of narcolepsy, transfer of the orexin gene into surrogate neurons has been successful in ameliorating narcoleptic symptoms. However, it is not known whether this method also blocks cataplexy triggered by strong emotions. To examine this possibility, the gene encoding mouse prepro-orexin was transferred into amygdala neurons of orexin-knockout (KO) mice (rAAV-orexin; n = 8). Orexin-KO mice that did not receive gene transfer (no-rAAV; n = 7) or received only the reporter gene (rAAV-GFP; n = 7) served as controls. Three weeks later, the animal's sleep and behaviour were recorded at night (no-odour control night), followed by another recording at night in the presence of predator odour (odour night). Orexin-KO mice given the orexin gene transfer into surrogate amygdala neurons had significantly less spontaneous bouts of cataplexy, and predator odour did not induce cataplexy compared with control mice. Moreover, the mice with orexin gene transfer were awake more during the odour night. These results demonstrate that orexin gene transfer into amygdala neurons can suppress both spontaneous and emotion-induced cataplexy attacks in narcoleptic mice. It suggests that manipulating amygdala pathways is a potential strategy for treating cataplexy in narcolepsy.

The impact of streetlights on an aquatic invasive species: Artificial light at night alters signal crayfish behaviour

Artificial light at night (ALAN) can significantly alter the behaviour, communication and orientation of animals, and will potentially interact with other stressors to affect biodiversity. Invasive, non-native species are one of the largest threats to freshwater biodiversity; however, the impact of ALAN on such species is unknown. This study assessed the effects of ALAN at ecologically relevant levels on the behaviour of a globally widespread invasive species, the signal crayfish (Pacifastacus leniusculus). In experimental aquaria, crayfish were exposed to periods of daylight, control (<0.1lx) and street-lit nights to test two hypotheses: (1) signal crayfish under natural conditions are nocturnal animals, spending more time in shelter during the day, whilst active and interacting during the night, and (2) ALAN reduces crayfish activity and intraspecific interactions, whilst increasing their propensity to use shelter. Our results confirm that signal crayfish are largely nocturnal, showing peak activity and interaction levels during control nights, whilst taking refuge during daylight hours. When exposed to short-term simulated light pollution from a streetlight at night however, activity and interactions with conspecifics were significantly reduced compared to control nights, whilst time spent in shelters increased. By altering crayfish behaviour, ALAN may change the ecosystem impacts of invasive crayfish in the wild. This study is the first to show an impact of ALAN on the behaviour of an invasive, non-native species, and provides information for the management of invasive crayfish in areas where ALAN is prevalent.

Sophisticated evaluation of possible effect of distinct auditory stimulation during REM sleep on dream content

Introducti o n : Studies have revealed significant impacts of different external stimuli during sleep on dream content and have reported various incorporation rates. The present study was performed to evaluate possible effect of auditory stimulation with sophisticated method. Materials and Methods: For this purpose, fifteen healthy male volunteers, who were tested for having normal auditory sensation, slept for two consecutive nights on sleep laboratory and monitored by polysomnography device. Subjects were not informed about content and time in which the sound was played. Traffic ambience sound (40‐60 decibel for 1 minute) played during second Rapid eye movement (REM) sleep of experimental (second) night and self-written dream report has collected after second and fourth REM sleep of both nights. Dream reports were coded by two independent coders according the Hall and de castle coding rules. Results: Dreaming something related to traffic sound (according to coding rules) was reported significantly more in dream reports of second REM of experimental night (in which sound was played) in comparison to dream reports of second REM of control night(p=0.033). Direct incorporation of traffic sound was reported in 78% subjects. Conclusion: Our finding revealed that information processing of auditory stimuli continues during sleep and can affect dream content, much more than previously estimated. The evaluation of possible correlated EEG changes when dream has been affected by external auditory stimuli is needed in future studies.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea.

To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. Within-subject and between-subjects. Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea.

Labile sleep promotes awareness of abstract knowledge in a serial reaction time task.

Sleep has been identified as a critical brain state enhancing the probability of gaining insight into covert task regularities. Both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep have been implicated with offline re-activation and reorganization of memories supporting explicit knowledge generation. According to two-stage models of sleep function, offline processing of information during sleep is sequential requiring multiple cycles of NREM and REM sleep stages. However, the role of overnight dynamic sleep macrostructure for insightfulness has not been studied so far. In the present study, we test the hypothesis that the frequency of interactions between NREM and REM sleep stages might be critical for awareness after sleep. For that aim, the rate of sleep stage transitions was evaluated in 53 participants who learned implicitly a serial reaction time task (SRTT) in which a determined sequence was inserted. The amount of explicit knowledge about the sequence was established by verbal recall after a night of sleep following SRTT learning. Polysomnography was recorded in this night and in a control night before and was analyzed to compare the rate of sleep-stage transitions between participants who did or did not gain awareness of task regularity after sleep. Indeed, individual ability of explicit knowledge generation was strongly associated with increased rate of transitions between NREM and REM sleep stages and between light sleep stages and slow wave sleep. However, the rate of NREM–REM transitions specifically predicted the amount of explicit knowledge after sleep in a trait-dependent way. These results demonstrate that enhanced lability of sleep goes along with individual ability of knowledge awareness. Observations suggest that facilitated dynamic interactions between sleep stages, particularly between NREM and REM sleep stages play a role for offline processing which promotes rule extraction and awareness.

Predictive Low-Glucose Insulin Suspension Reduces Duration of Nocturnal Hypoglycemia in Children Without Increasing Ketosis.

OBJECTIVENocturnal hypoglycemia can cause seizures and is a major impediment to tight glycemic control, especially in young children with type 1 diabetes. We conducted an in-home randomized trial to assess the efficacy and safety of a continuous glucose monitor–based overnight predictive low-glucose suspend (PLGS) system.RESEARCH DESIGN AND METHODSIn two age-groups of children with type 1 diabetes (11–14 and 4–10 years of age), a 42-night trial for each child was conducted wherein each night was assigned randomly to either having the PLGS system active (intervention night) or inactive (control night). The primary outcome was percent time <70 mg/dL overnight.RESULTSMedian time at <70 mg/dL was reduced by 54% from 10.1% on control nights to 4.6% on intervention nights (P < 0.001) in 11–14-year-olds (n = 45) and by 50% from 6.2% to 3.1% (P < 0.001) in 4–10-year-olds (n = 36). Mean overnight glucose was lower on control versus intervention nights in both age-groups (144 ± 18 vs. 152 ± 19 mg/dL [P < 0.001] and 153 ± 14 vs. 160 ± 16 mg/dL [P = 0.004], respectively). Mean morning blood glucose was 159 ± 29 vs. 176 ± 28 mg/dL (P < 0.001) in the 11–14-year-olds and 154 ± 25 vs. 158 ± 22 mg/dL (P = 0.11) in the 4–10-year-olds, respectively. No differences were found between intervention and control in either age-group in morning blood ketosis.CONCLUSIONSIn 4–14-year-olds, use of a nocturnal PLGS system can substantially reduce overnight hypoglycemia without an increase in morning ketosis, although overnight mean glucose is slightly higher.

A laboratory experiment to determine the dispersal response of Atlantic salmon (Salmo salar) fry to street light intensity

Summary The effect of a range of ecologically relevant broader spectrum street light intensities on the dispersal timing of Atlantic salmon (Salmo salar) fry was investigated to assess the efficacy of a proposed management tool, the dimming of lamp brightness, for reducing the ecological consequences of artificial night light on aquatic ecosystems. Dispersal timing under treatment street light intensities of 8, 4, 2 and 1 lux was compared to that under a control night light intensity of 0.1 lux, representative of approximately half that experienced from a full moon. Dispersal timing was significantly delayed (by 1.4 to 2.2 days), and its diel pattern significantly disrupted under the treatment street light intensities. However, the dose–response for both delay and disruption effects was not linear, with a strong effect apparent at 1 lux, and little or no additional impact seen when the light intensity was increased further. Under control conditions, the mean time of dispersal was 3:58 h after dusk, with very few fry (&lt;4%) dispersing during daylight hours. For the treatment street light intensities, the mean time of dispersal of fry was significantly later (5:31 h after dusk at 1 lux) at night, and a much wider distribution of fry dispersal times was apparent with many more fry (19% at 1 lux) dispersing during daylight hours. Survival to dispersal in aquarium conditions was high (≥97.8%) and comparable in the control and treatment street light intensities. However, in the wild, the period between fry dispersal and the establishment of feeding territories is considered to be of critical importance in the dynamics of salmonid populations and any disruption may significantly increase predation and reduce fitness. The findings of this aquarium‐based investigation suggest that the dimming of lamp brightness has little potential as a successful management strategy to reduce the disruptive impact of street lighting surrounding freshwater ecosystems. We therefore recommend that the best course of action is to maintain and increase natural unlit areas.

Involvement of sleep spindles in overnight declarative memory stabilization

Objective Numerous studies point to the involvement of sleep spindles and slow waves in memory processes, particularly in hippocampus-dependent declarative memory. We have shown previously that the overnight change in recall performance in a declarative word pair association task correlates significantly with increased spindle activity during the night after learning compared to a control night. The current study re-evaluates this relationship in detail and explores whether the observed positive correlation of two spindle parameters measured during stage 2 (S2) sleep with overnight stabilization depend on the time of night (early vs. late) and spindle type (fast vs. slow).

Abstracts from ATTD 20158th International Conference on Advanced Technologies &amp; Treatments for DiabetesParis, France—February 18–21, 2015

Abstracts from ATTD 20158th International Conference on Advanced Technologies &amp; Treatments for DiabetesParis, France—February 18–21, 2015

MD-Logic overnight control for 6 weeks of home use in patients with type 1 diabetes: randomized crossover trial.

We evaluated the effect of the MD-Logic system on overnight glycemic control at patients' homes. Twenty-four patients (aged 12-43 years; average A1c 7.5 ± 0.8%, 58.1 ± 8.4 mmol/mol) were randomly assigned to participate in two overnight crossover periods, each including 6 weeks of consecutive nights: one under closed loop and the second under sensor-augmented pump (SAP) therapy at patients' homes in real-life conditions. The primary end point was time spent with sensor glucose levels below 70 mg/dL (3.9 mmol/L) overnight. Closed-loop nights significantly reduced time spent in hypoglycemia (P = 0.02) and increased the percentage of time spent in the target range of 70-140 mg/dL (P = 0.003) compared with nights when the SAP therapy was used. The time spent in substantial hyperglycemia above 240 mg/dL was reduced by a median of 52.2% (interquartile range [IQR] 4.8, 72.9%; P = 0.001) under closed-loop control compared with SAP therapy. Overnight total insulin doses were lower in the closed-loop nights compared with the SAP nights (P = 0.04). The average daytime glucose levels after closed-loop operation were reduced by a median of 10.0 mg/dL (IQR -2.7, 19.2; P = 0.017) while lower total insulin doses were used (P = 0.038). No severe adverse events occurred during closed-loop control; there was a single event of severe hypoglycemia during a control night. The long-term home use of automated overnight insulin delivery by the MD-Logic system was found to be a feasible, safe, and an effective tool to reduce nocturnal hypoglycemia and improve overnight glycemic control in subjects with type 1 diabetes.

Nighttime aircraft noise impairs endothelial function and increases blood pressure in patients with or at high risk for coronary artery disease.

AimsEpidemiological studies suggest the existence of a relationship between aircraft noise exposure and increased risk for myocardial infarction and stroke. Patients with established coronary artery disease and endothelial dysfunction are known to have more future cardiovascular events. We therefore tested the effects of nocturnal aircraft noise on endothelial function in patients with or at high risk for coronary artery disease.Methods60 Patients (50p 1–3 vessels disease; 10p with a high Framingham Score of 23 %) were exposed in random and blinded order to aircraft noise and no noise conditions. Noise was simulated in the patients’ bedroom and consisted of 60 events during one night. Polygraphy was recorded during study nights, endothelial function (flow-mediated dilation of the brachial artery), questionnaires and blood sampling were performed on the morning after each study night.ResultsThe mean sound pressure levels L eq(3) measured were 46.9 ± 2.0 dB(A) in the Noise 60 nights and 39.2 ± 3.1 dB(A) in the control nights. Subjective sleep quality was markedly reduced by noise from 5.8 ± 2.0 to 3.7 ± 2.2 (p < 0.001). FMD was significantly reduced (from 9.6 ± 4.3 to 7.9 ± 3.7 %; p < 0.001) and systolic blood pressure was increased (from 129.5 ± 16.5 to 133.6 ± 17.9 mmHg; p = 0.030) by noise. The adverse vascular effects of noise were independent from sleep quality and self-reported noise sensitivity.ConclusionsNighttime aircraft noise markedly impairs endothelial function in patients with or at risk for cardiovascular disease. These vascular effects appear to be independent from annoyance and attitude towards noise and may explain in part the cardiovascular side effects of nighttime aircraft noise.

Overnight glucose control with an automated, unified safety system in children and adolescents with type 1 diabetes at diabetes camp.

OBJECTIVETo determine the safety and efficacy of an automated unified safety system (USS) in providing overnight closed-loop (OCL) control in children and adolescents with type 1 diabetes attending diabetes summer camps.RESEARCH DESIGN AND METHODSThe Diabetes Assistant (DIAS) USS used the Dexcom G4 Platinum glucose sensor (Dexcom) and t:slim insulin pump (Tandem Diabetes Care). An initial inpatient study was completed for 12 participants to evaluate safety. For the main camp study, 20 participants with type 1 diabetes were randomized to either OCL or sensor-augmented therapy (control conditions) per night over the course of a 5- to 6-day diabetes camp.RESULTSSubjects completed 54 OCL nights and 52 control nights. On an intention-to-treat basis, with glucose data analyzed regardless of system status, the median percent time in range, from 70–150 mg/dL, was 62% (29, 87) for OCL nights versus 55% (25, 80) for sensor-augmented pump therapy (P = 0.233). A per-protocol analysis allowed for assessment of algorithm performance. The median percent time in range, from 70–150 mg/dL, was 73% (50, 89) for OCL nights (n = 41) versus 52% (24, 83) for control conditions (n = 39) (P = 0.037). There was less time spent in the hypoglycemic range <50, <60, and <70 mg/dL during OCL compared with the control period (P = 0.019, P = 0.009, and P = 0.023, respectively).CONCLUSIONSThe DIAS USS algorithm is effective in improving time spent in range as well as reducing nocturnal hypoglycemia during the overnight period in children and adolescents with type 1 diabetes in a diabetes camp setting.

Effect of acute sleep deprivation and recovery on Insulin-like Growth Factor-I responses and inflammatory gene expression in healthy men.

Acute sleep deprivation in humans has been found to increase inflammatory markers and signaling pathways in the periphery through a possible Toll-like receptor 4 (TLR-4). In addition, short duration sleep has been associated with low circulating total Insulin-like Growth Factor-I (IGF-I) concentrations. We aimed to determine whether a total sleep deprivation (TSD) protocol with recovery altered whole-blood gene expression of the proinflammatory cytokines TNF-α and IL-6, as well as TLR-4 expression, and to examine the relationship with circulating concentrations of the IGF-I system. Twelve healthy men participated in a five-day TSD (two control nights followed by one night of sleep deprivation and one night of recovery). Blood was sampled at 0800, before and after sleep deprivation (D2 and D4), and after recovery (D5). It is shown that 25 h of sleep deprivation (D4) induced significant increases in mRNA levels of TNF-α and its soluble receptor R1 (P<0.01 respectively), as well as TLR-4 (P<0.05), while IL-6 mRNA levels remained unchanged. Circulating concentrations of free IGF-I were decreased at D4 (P<0.001). One night of recovery was sufficient to restore basal expression levels for TNF-α, sTNF-R1, TLR-4 and circulating IGF-I. Changes in TLR-4 mRNA levels during the protocol correlated positively with those of TNF-α and sTNF-R1 (r=0.393 and r=0.490 respectively), and negatively with circulating free IGF-I (r=-0.494). In conclusion, 25 h of sleep deprivation in healthy subjects is sufficient to induce transient and reversible genomic expression of the pro-inflammatory cytokine TNF-α and its R1 receptor, and its mediator TLR-4, with a possible link to IGF-I axis inhibition.

Low intensity light of different colours modifies Atlantic salmon depth use

Underwater anti-maturation-lights have recently been exploited to position sea-caged Atlantic salmon (Salmo salar L.) deeper at night in an effort to reduce infections by salmon lice (Lepeophtheirus salmonis) in surface layers. However, anti-maturation-light use is impermanent because lighting during decreasing day-lengths stimulates sexual maturation which is detrimental for fish welfare, growth and meat quality. The effects from lights on maturation are related to both light intensity and light spectrum. Here, we explored caged salmon depth use in response to lights of four low intensities (0.01, 0.10, 1.0 and 10.0μE as measured 1m from the lamps) and seven different colours (broadband white LED lamp and narrow spectrum violet, blue, green, yellow, red and deep red LED lamps). Triplicate sea cages (12×12m and 11m deep) holding approximately 5000 fish of 1.5kg were exposed to each light positioned at 10m depth for one night. Echo sounders registered fish vertical positioning on nights of light treatments and no light (control nights) before and after each light exposure. Results showed that submerged lights generally caused fish to maintain their day-time swimming depth near 10m (light depth) during the night, as opposed to the typical migration of salmon to upper cage depths at dusk observed on control nights. Quantities of fish staying deep decreased with lowered light intensity, but even 0.1μE had effects. All light colours, except deep red, significantly affected swimming depth, with a trend of increased effect at lower wavelength colours. Temperature stratification strengthened light effects when warmer water was near the lamps and weakened effects in the case of warmer water near the surface. This study opens up the potential of using low intensity lights at decreasing day-lengths that may not affect sexual maturation and remain suitable for guiding salmon away from surface waters rich in lice infective stages.