Targeted memory reactivation of face-name learning depends on ample and undisturbed slow-wave sleep

Face memory, including the ability to recall a person’s name, is of major importance in social contexts. Like many other memory functions, it may rely on sleep. We investigated whether targeted memory reactivation during sleep could improve associative and perceptual aspects of face memory. Participants studied 80 face-name pairs, and then a subset of spoken names with associated background music was presented unobtrusively during a daytime nap. This manipulation preferentially improved name recall and face recognition for those reactivated face-name pairs, as modulated by two factors related to sleep quality; memory benefits were positively correlated with the duration of stage N3 sleep (slow-wave sleep) and negatively correlated with measures of sleep disruption. We conclude that (a) reactivation of specific face-name memories during sleep can strengthen these associations and the constituent memories, and that (b) the effectiveness of this reactivation depends on uninterrupted N3 sleep.

Differentiating perinatal Insomnia Disorder and sleep disruption: A longitudinal study from pregnancy to 2 years postpartum

Study Objectives Insomnia Disorder diagnoses require persistent sleep complaints despite “adequate sleep opportunity”. Significant perinatal sleep disruption makes this diagnosis challenging. This longitudinal study distinguished between Insomnia Disorder and Perinatal Sleep Disruption and their sleep and mental health correlates. Methods 163 nulliparous females (age M±SD=33.35±3.42) participating in a randomised-controlled trial repeated the Insomnia Disorder module of the Duke Structured Interview for Sleep Disorders and PROMIS measures for sleep and mental health at 30 and 35 weeks’ gestation, and 1.5, 3, 6, 12, and 24 months postpartum (944 interviews, 1009 questionnaires completed). We compared clinical features when DSM-5 Insomnia Disorder criteria were: (1) met (Insomnia Disorder), (2) not met only because of the sleep opportunity criteria (Perinatal Sleep Disruption), and (3.) not met due to other criteria (Low Complaint). Results Proportions of Insomnia Disorder were 16.0% and 19.8% during early and late third trimester, and ranged 5.3-11.7% postpartum. If the sleep opportunity criteria were not considered, rates of Insomnia would be 2-4 times higher (21.4-40.4%) across time-points. Mixed effects models adjusting for covariates showed that compared to Low Complaint, both Insomnia Disorder and Perinatal Sleep Disruption scored significantly higher on insomnia and sleep disturbance scales, sleep effort, and sleep-related impairments (p-values<.01), but depression and anxiety were comparable (p-values>.12). Conclusion Assessing sleep complaints without considering sleep opportunity can result in over-diagnosis of Insomnia Disorder in the perinatal periods. Insomnia Disorder and perinatal sleep disruption were associated with adverse sleep and mood outcomes, and need to be carefully differentiated and appropriately addressed.

Hypocretin in locus coeruleus and dorsal raphe nucleus mediates inescapable footshock stimulation (IFS)-induced REM sleep alteration

Hypocretin (hcrt) is a stress-reacting neuropeptide mediating arousal and energy homeostasis. An inescapable footshock stimulation (IFS) could initiate the hcrt release from the lateral hypothalamus (LHA) and suppresses rapid eye movement (REM) sleep in rodents. However, the effects of the IFS-induced hcrts on REM-off nuclei, the locus coeruleus (LC) and dorsal raphe nucleus (DRN), remained unclear. We hypothesized that the hcrt projections from the LHA to LC or DRN mediate IFS-induced sleep disruption. Our results demonstrated that the IFS increased hcrt expression and the neuronal activities in the LHA, hypothalamus, brainstem, thalamus, and amygdala. Suppressions of REM sleep and slow wave activity during non-REM (NREM) sleep caused by the high expression of hcrts were blocked when a non-specific and dual hcrt receptor antagonist was administered into the LC or DRN. Furthermore, the IFS also caused an elevated innate anxiety, but was limitedly influenced by the hcrt antagonist. This result suggests that the increased hcrt concentrations in the LC and DRN mediate stress-induced sleep disruptions and might partially involve IFS-induced anxiety.

Quercetin Modulates Behavioural and Biochemical Alterations in Stressed Mice

Disruption of the active phase of sleep alters the physiological homeostasis of the body and results in oxidative breakdown which may trigger a wide array of defects. The central nervous system and the metabolic system are some of the most affected systems as described in several literatures. Some plant based compounds with antioxidant property have been previously described in the abrogation of the deleterious effects of active sleep disruption. One of such compounds is quercetin. This study was premeditated to expatiate on the probable neuroprotective effect of quercetin on mice exposed to 72hr active sleep disruption. Mice were allotted into five treatment groups (n = 6): group 1 served as control, group 2 received 10 mL/kg vehicle, groups 3 and 4 received 25 and 50 mg/kg quercetin respectively, and group 5 received 50 mg/kg astaxanthin. Treatment lasted for 7 days while groups 2-5 were exposed to the sleep deprivation protocol starting from day 4. Behavioural tests followed by biochemical assays and histopathological changes in the prefrontal cortex were evaluated. Data were analysed by ANOVA set at p<0.05 significance. The results revealed that quercetin, in both doses, significantly amplified memory performance, attenuated depression-like behaviour, replenished catalase and superoxide dismutase, attenuated nitric oxide levels in brain and liver of mice when compared to control group and protected against loss of prefrontal cortex neurons. In conclusion, quercetin possesses protective effects against sleep deprivation-induced brain damage.

Factors affecting sleep quality in patients with systemic lupus erythematosus

Objective This study aimed to assess the sleep quality and the factors affecting the sleep quality in patients with SLE. Methods This was a descriptive and cross-sectional study conducted in 105 patients with SLE who were admitted to the rheumatology polyclinic of a university hospital between May and July 2017. The data were collected using a “Patient Description Form” and the “Pittsburgh Sleep Quality Index (PSQI).” Results The total mean (standard deviation) PSQI score of the patients was 7.81 (3.11). Duration of disease, presence of comorbid diseases, side effects of drugs, and sleep disruption and related problems were identified as factors affecting sleep quality. The model of the regression showed that side effects of drugs, sleep disruption, and trouble falling asleep suffered higher PSQI score (bad sleep quality). Conclusions Results of this study showed that the sleep quality was generally poor in patients with SLE. Sleep quality was affected by some disease and sleep variables. Therefore, comprehensive sleep evaluation is necessary in the planning of treatment and care of SLE patients and to implement initiatives to improve sleep patterns in these patients.

Narcolepsy with intermediate cerebrospinal level of hypocretin-1

Study objectives To describe the phenotype of narcolepsy with intermediate cerebrospinal hypocretin-1 levels (CSF hcrt-1). Methods From 1600 consecutive patients with narcolepsy from Bologna and Montpellier sleep centers we selected patients with intermediate CSF hcrt-1 levels (110-200 pg/ml). Clinical, neurophysiological and biological data were contrasted for the presence of cataplexy, HLA-DQB1*06:02, and median CSF hcrt-1 levels (149.34 pg/mL). Results Forty-five (55% males, aged 35 ± 17 years) patients (2.8% of all cases) were included. Thirty-three (73%) were HLA-DQB1*06:02, 29 (64%) reported cataplexy (21, 72.4% with typical features), and 5 (11%) had presumed secondary etiology. Cataplexy was associated with other core narcolepsy symptoms, increased sleep onset REM periods, and nocturnal sleep disruption. Cataplexy and irrepressible daytime sleep were more frequent in HLA DQB1*06:02 positive patients. Lower CSF hcrt-1 levels were associated with hallucinations. Conclusion Narcolepsy with intermediate CSF hcrt-1 level is a rare condition with heterogeneous phenotype. HLA DQB1*06:02 and lower CSF hcrt-1 were associated with typical narcolepsy features, calling for future research to distinguish incomplete from secondary narcolepsy forms.

Sex-dependent changes in murine striatal dopamine release, sleep, and behavior during spontaneous Δ-9-tetrahydrocannabinol abstinence

Withdrawal symptoms are observed upon cessation of cannabis use in humans. Although animal studies have examined withdrawal symptoms following exposure to delta-9-tetrahydrocannabinol (THC), difficulties in obtaining objective measures of spontaneous withdrawal using paradigms that mimic cessation of use in humans have slowed research. The neuromodulator dopamine (DA) is known to be affected by chronic THC treatment and plays a role in many behaviors related to human THC withdrawal symptoms. These symptoms include sleep disturbances that often drive relapse, and emotional behaviors, e.g., irritability and anhedonia. We examined THC withdrawal-induced changes in striatal DA release and the extent to which sleep disruption and behavioral maladaptation manifest during withdrawal in a mouse chronic cannabis exposure model. Using a THC treatment regimen known to produce tolerance we measured electrically elicited DA release in acute brain slices from different striatal subregions during early and late THC abstinence. Long-term polysomnographic recordings from mice were used to assess vigilance state and sleep architecture before, during, and after THC treatment. We additionally assessed how behaviors that model human withdrawal symptoms are altered by chronic THC treatment in early and late abstinence. We detected altered striatal DA release, sleep disturbances that mimic clinical observations, and behavioral maladaptation in mice following tolerance inducing THC treatment. Sex differences were observed in nearly all metrics. Altered striatal DA release, sleep and affect-related behaviors associated with spontaneous THC abstinence were more consistently observed in male mice. To our knowledge these findings provide the first model of directly translatable non-precipitated cannabis withdrawal symptoms, in particular, sleep disruption.

Hericium erinaceus mycelium ameliorate anxiety induced by continuous sleep disturbance in vivo

Background Sleep disruption is a major public health issue and may increase the risk of mortality by ten-folds if an individual is sleeping less than 6 h per night. Sleep has changed dramatically during to the COVID-19 pandemic because COVID symptoms can lead to psychological distress including anxiety. Hericium erinaceus mycelium has been widely investigated in both the in vivo studies and clinical trials for its neuroprotective functions because the mycelium contains hericenones and erinacines, which synthesize the nerve growth factor and brain-derived neurotrophic factor (BDNF). Recent in vivo reports have shown showed that erinacine A-enriched Hericium erinaceus mycelium can modulate BDNF/TrkB/PI3K/Akt/GSK-3β pathways to induce an antidepressant-like effect. A large body of evidence indicates that erinacine can pass the blood-brain barrier and suggests its neuroprotective function in both peripheral and central nervous systems. Thus, Hericium erinaceus mycelium may be a dual-function supplement for sleep disruption improvement while sustaining anxiolytic effects. Method To simulate the condition of sleep disruption, the mice were subjected to the tail suspension test (TST) for 15 min every day during the same period for nine consecutive days. Two different doses (75 and 150 mg/kg) of Hericium erinaceus mycelium were administered orally 20 min prior to the TSTs before entering the light period of 12:12 h L:D cycle. All sleep-wake recording was recorded for 24 h using electroencephalogram and electromyogram. The elevated-plus-maze and open-field tests were conducted to record the behavior activities. Results Consecutive TSTs prior to the light period could cause significant sleep disturbance and anxiety behavior in the elevated-plus-maze experiments. Results showed that administration with Hericium erinaceus mycelium at 150 mg/kg ameliorated the rodent anxiety (p < 0.05) and reversed the TST-induced NREM sleep disturbance in the dark period. Conclusion This is the first in vivo study suggesting that Hericium erinaceus mycelium has a dual potential role for anxiety relief through improving sleep disruptions.