Effects of cocaine, methamphetamine and modafinil challenge on sleep rebound after paradoxical sleep deprivation in rats

Insomnia, Daytime Sleepiness, and Quality of Life among 20,139 College Students in 60 Countries around the World-A 2016-2021 Study

Background: Sleep disorders are a widespread phenomenon, and the number of individuals suffering from them is increasing every year, especially among young adults. Currently, the literature lacks studies that cover both countries with different levels of development and a period before the announcement of the ongoing COVID-19 pandemic. Therefore, this study aims to globally assess the prevalence of insomnia and daytime sleepiness among students and assess their quality of life. Methods: For this purpose, our own questionnaire was distributed online via Facebook.com. In addition to the questions that assessed socioeconomic status, the survey included psychometric tools, such as the Athens insomnia scale (AIS), the Epworth sleepiness scale (ESS), and the Manchester short assessment of the quality of life (MANSA). The survey distribution period covered 31 January 2016 to 30 April 2021. Results: The survey involved 20,139 students from 60 countries around the world. The vast majority of the students were women (78.2%) and also those residing in countries with very high levels of development and/or high GDP (gross domestic product) per capita at 90.4% and 87.9%, respectively. More than half (50.6%) of the respondents (10,187) took the survey before the COVID-19 pandemic was announced. In the group analyzed, 11,597 (57.6%) students obtained a score indicative of insomnia and 5442 (27.0%) a score indicative of daytime sleepiness. Women, low-income residents, and nonmedical students were significantly more likely to have scores indicating the presence of insomnia. Individuals experiencing both sleepiness (B = −3.142; p < 0.001) and daytime sleepiness (B = −1.331; p < 0.001) rated their quality of life significantly lower. Conclusions: Insomnia and excessive daytime sleepiness are common conditions among students worldwide and are closely related. The COVID-19 pandemic significantly altered students’ diurnal rhythms, which contributed to an increase in insomnia. Students in countries with a high GDP per capita index are significantly less likely to develop insomnia compared to the residents of countries with a low GDP per capita index. Sleep disorders definitely reduce the quality of life of students.

Application of armodafinil-loaded microneedle patches against the negative influence induced by sleep deprivation

Cognition maintenance is essential for healthy and safe life if sleep deprivation happens. Armodafinil is a wake-promoting agent against sleep deprivation related disorders. However, only the tablet formulation is available, which may limit its potential in some circumstances. Here, we report the synthesis of a new formulation of armodafinil, microneedle patches, which can be conveniently used by any individual and removed in time if not wanted. To produce the needles of higher mechanical strength and higher drug loading, polyvinylpyrrolidone (PVP) K90 was used to fabricate armodafinil-loaded microneedles by applying the mold casting method after dissolving in methanol and drying. The higher mechanical strength was validated by COMSOL Multiphysics® software stimulation and universal mechanical testing machines. The obtained armodafinil microneedles can withstand a force of 70 N and penetrate the skin to a depth of 230 μm, and quickly released the drug within 1.5 h in vitro. The pharmacokinetic analysis showed that microneedle administration can maintain a more lasting and stable blood concentration as compared to oral administration. After the treatment of sleep deprived mice with microneedles, the in vivo pharmacodynamics study clearly demonstrated that armodafinil microneedles could eliminate the effects of sleep deprivation and improve the cognitive functions of sleep-deprived mice. A self-administered, high drug-loaded microneedle patch were prepared successfully, which appeared to be highly promising in preserving cognition by transdermal administration.

The implications of sleep disruption for cognitive and affective processing in methamphetamine abuse

Sleep is disrupted during active use of methamphetamine (MA), during withdrawal from the drug, and during abstinence from its use. However, relatively little is known about possible mediatory functions of disrupted sleep in the emergence, manifestation, and maintenance of cognitive and affective symptoms of MA abuse. We hypothesise that sleep functions as a mediator for stimulant drug effects. Specifically, we propose that objectively-measured sleep parameters can be used to explain some of the variability in the experience and presentation of memory deficits and emotion dysregulation in MA abusers. After describing how important healthy sleep is to unimpaired cognitive and affective functioning, we review literature describing how sleep is disrupted in MA abuse. Then, we provide a conceptual framework for our hypothesis by explaining the relationship between MA abuse, sleep disruption, memory deficits, emotion dysregulation, and changes in reward-related brain networks. We conclude by discussing implications of the hypothesis for research and treatment.

Anxiety-like effects of meta-chlorophenylpiperazine in paradoxically sleep-deprived mice

Chlorophenylpiperazines (CPP) are psychotropic drugs used in nightclub parties and are frequently used in a state of sleep deprivation, a condition which can potentiate the effects of psychoactive drugs. This study aimed to investigate the effects of sleep deprivation and sleep rebound (RB) on anxiety-like measures in mCPP-treated mice using the open field test. We first optimized our procedure by performing dose-effect curves and examining different pretreatment times in naïve male Swiss mice. Subsequently, a separate cohort of mice underwent paradoxical sleep deprivation (PSD) for 24 or 48h. In the last experiment, immediately after the 24h-PSD period, mice received an injection of saline or mCPP, but their general activity was quantified in the open field only after the RB period (24 or 48h). The dose of 5mgmL(-1) of mCPP was the most effective at decreasing rearing behavior, with peak effects 15min after injection. PSD decreased locomotion and rearing behaviors, thereby inhibiting a further impairment induced by mCPP. Plasma concentrations of mCPP were significantly higher in PSD 48h animals compared to the non-PSD control group. Twenty-four hours of RB combined with mCPP administration produced a slight reduction in locomotion. Our results show that mCPP was able to significantly change the behavior of naïve, PSD, and RB mice. When combined with sleep deprivation, there was a higher availability of drug in plasma levels. Taken together, our results suggest that sleep loss can enhance the behavioral effects of the potent psychoactive drug, mCPP, even after a period of rebound sleep.

Infusion of modafinil into anterior hypothalamus or pedunculopontine tegmental nucleus at different time-points enhances waking and blocks the expression of recovery sleep in rats after sleep deprivation

Clinical studies have indicated that the primary pharmacological activity of modafinil (MOD) is inducing wakefulness; however, the brain targets that underlie its wake-promoting activity have not been described. In the present study, we show that MOD injected into sleep-wake related brain areas promoted alertness. If administered (10, 20, or 30 μg/1 μL) into either anterior hypothalamus (AH) or pedunculopontine tegmental nucleus (PPTg) at 08:00, 12:00 or 16:00 h, MOD enhanced wakefulness whereas diminished slow wave sleep as well as rapid eye movement sleep. In addition, microinjection of MOD (10, 20, or 30 μg/1 μL) either into AH or PPTg after total sleep deprivation prevented the sleep rebound. Taken together, these observations suggest that AH and PPTg play a key role in the wake-inducing effects of MOD and encourage further experimentation to draw a possible mechanism of action.

Wake-promoting agent modafinil worsened attentional performance following REM sleep deprivation in a young-adult rat model of 5-choice serial reaction time task

RATIONALE

Individuals who experience sleep loss may exhibit certain physiological abnormalities. Central stimulant drugs have been studied in sleep-loss conditions, and some of them might be therapeutically beneficial. Modafinil (diphenyl-methyl-sulfinyl-2-acetamide, MOD) has been increasingly employed for elevating alertness and vigilance in recent years, yet the underlying mechanism of actions for MOD is not fully understood.

OBJECTIVES

To examine the behavioral effect of MOD following rapid eye movement sleep deprivation (REMD) in rats. A five-choice serial reaction time task (5-CSRTT) was employed to investigate animals' attentional performance and impulsive reactivity.

MATERIALS AND METHODS

Rats of different ages were trained to learn the 5-CSRTT. REMD with the water platform method was applied for 96 h. The impacts of REMD on 5-CSRTT in middle-age (32-weeks-old) and young-adult (12-week-old) rats were compared with baseline or a condition with shorter visual stimulus duration.

RESULTS

The results revealed that following REMD, young-adult but not middle-age rats were liable to be affected in their performances of the 5-CSRTT. In young-adult rats, while MOD had no contributions to the effect of REMD, it worsened rats' performance following REMD when the stimulus duration was shortened, as shown by the reduced number of correct responses and prolonged magazine latency.

CONCLUSIONS

These results suggest that aging might be a crucial factor for the physiological impact following REMD. MOD should be used cautiously, particularly, in conditions that require REM sleep.

Sleep loss and acute drug abuse can induce DNA damage in multiple organs of mice

The purpose of the present study was to characterize the genetic damage induced by paradoxical sleep deprivation (PSD) in combination with cocaine or ecstasy (3,4-methylenedioxymethamphetamine; MDMA) in multiple organs of male mice using the single cell gel (comet) assay. C57BL/6J mice were submitted to PSD by the platform technique for 72 hours, followed by drug administration and evaluation of DNA damage in peripheral blood, liver and brain tissues. Cocaine was able to induce genetic damage in the blood, brain and liver cells of sleep-deprived mice at the majority of the doses evaluated. Ecstasy also induced increased DNA migration in peripheral blood cells for all concentrations tested. Analysis of damaged cells by the tail moment data suggests that ecstasy is a genotoxic chemical at the highest concentrations tested, inducing damage in liver or brain cells after sleep deprivation in mice. Taken together, our results suggest that cocaine and ecstasy/MDMA act as potent genotoxins in multiple organs of mice when associated with sleep loss.

Dopamine transporter regulation during four nights of REM sleep deprivation followed by recovery--an in vivo molecular imaging study in humans

OBJECTIVES

To assess the influence of total or selective REM sleep deprivation on the dopamine transporter (DAT) densities and sleep patterns of healthy volunteers.

DESIGN

Prospective study.

SETTING

Evaluation of polysomnography recordings and DAT density after 4 nights of selective REM sleep deprivation followed by 3 nights of sleep recovery compared to a control group and a group that was subjected to 2 nights of total sleep deprivation. Single positron emission computed tomography and [99mTc]TRODAT-1 were used to assess the cerebral DAT density in the striatum at baseline, after REM sleep deprivation and total sleep deprivation as well as after sleep recovery. Blood was collected daily to examine prolactin and estradiol levels, which were correlated with dopaminergic activity.

PATIENTS OR PARTICIPANTS

Thirty healthy male volunteers ranging from 19 to 29 years of age were randomly assigned to one of three experimental groups after giving written informed consent (10 non-sleep deprived, 10 total sleep deprived, and 10 REM sleep deprived).

MEASUREMENTS AND RESULTS

Four nights of REM sleep deprivation and 2 nights of total sleep deprivation induced distinct and heterogeneous patterns of sleep recovery. No significant modulation of DAT availability was observed within groups. In the recovery nights, changes in cortisol, prolactin and estradiol concentrations were significantly correlated with specific sleep stages in the total and REM sleep deprived groups. In addition, DAT density was positively correlated with estradiol concentration and inversely associated with SWS latency only after total sleep deprivation.

CONCLUSION

Our study demonstrates that although sleep deprivation did not promote significant alterations in DAT density within the striatum, there were significant correlations among transporter availability, hormonal concentrations and sleep parameters.

Electrophysiological correlates of sleep disturbance induced by acute and chronic administration of D-amphetamine

Sleep disturbance is the strongest predictor of manic relapse and is considered one of the most important objective measures of treatment response in bipolar disorder (BD). However, the neurobiological mechanisms underlying sleep disturbance in BD are poorly understood. The administration of psychostimulants to rodents can trigger a number of manic-like behaviors. Therefore, the present study aims to investigate the effects of single and repeated D-amphetamine (AMPH) administration on sleep patterns in rats. Sleep was continuously monitored during light periods after single and repeated (7 days) injections of AMPH (2 mg/kg, i.p.) or saline in adult Wistar rats using electrocorticogram and electromyographic recordings. Acute injections of AMPH suppressed sleep for the first 2 h, and were followed by a gradual increase in the amount of sleep. Both slow wave sleep (SWS) and paradoxical sleep (PS) were compromised. Repeated exposure to AMPH led to a drastic disruption of the sleep-wake cycle that was mainly characterized by a decrease of PS during all time-points recorded in comparison to the saline group. Furthermore, both acute and chronic AMPH administration induced longer latencies to both SWS and PS. These findings suggest that AMPH produces profound sleep disturbances and decreases PS sleep. Given that some of these abnormalities are observed in individuals with BD, this animal model can provide a means to investigate neurobiological aspects of sleep disturbance in BD, as well as their response to mood stabilizers.

Effects of sleep loss on sleep architecture in Wistar rats: gender-specific rebound sleep

This study was designed to examine the influence of gender on sleep rebound architecture after a 4-day paradoxical sleep deprivation period. After a 5-day baseline sleep recording, both male and female rats in different phases of the estrus cycle were submitted to paradoxical sleep deprivation for 96 h. After this period, the sleep rebound recording was evaluated for 5 days (one estrus cycle). The findings revealed that after paradoxical sleep deprivation, sleep efficiency and paradoxical sleep returned to baseline values on the second day of the light period, for all except the proestrus group. During the dark rebound period, only the female groups presented increased sleep efficiency on the first day. Paradoxical sleep returned to baseline values on the third day, except for males and the cycling females submitted to paradoxical sleep deprivation in the diestrus phase, whose baseline values returned to normal on the second day of rebound period. Thus, the females and males displayed distinct patterns as a result of sleep disruption.