Overnight neuronal plasticity and adaptation to emotional distress

Expressions such as 'sleep on it' refer to the resolution of distressing experiences across a night of sound sleep. Sleep is an active state during which the brain reorganizes the synaptic connections that form memories. This Perspective proposes a model of how sleep modifies emotional memory traces. Sleep-dependent reorganization occurs through neurophysiological events in neurochemical contexts that determine the fates of synapses to grow, to survive or to be pruned. We discuss how low levels of acetylcholine during non-rapid eye movement sleep and low levels of noradrenaline during rapid eye movement sleep provide a unique window of opportunity for plasticity in neuronal representations of emotional memories that resolves the associated distress. We integrate sleep-facilitated adaptation over three levels: experience and behaviour, neuronal circuits, and synaptic events. The model generates testable hypotheses for how failed sleep-dependent adaptation to emotional distress is key to mental disorders, notably disorders of anxiety, depression and post-traumatic stress with the common aetiology of insomnia.

Shining a Light on the Mechanisms of Sleep for Memory Consolidation

Purpose of review

This paper reviews all optogenetic studies that directly test various sleep states, traits, and circuit-level activity profiles for the consolidation of different learning tasks.

Recent findings

Inhibiting or exciting neurons involved either in the production of sleep states or in the encoding and consolidation of memories reveals sleep states and traits that are essential for memory. REM sleep, NREM sleep, and the N2 transition to REM (characterized by sleep spindles) are integral to memory consolidation. Neural activity during sharp-wave ripples, slow oscillations, theta waves, and spindles are the mediators of this process.

Summary

These studies lend strong support to the hypothesis that sleep is essential to the consolidation of memories from the hippocampus and the consolidation of motor learning which does not necessarily involve the hippocampus. Future research can further probe the types of memory dependent on sleep-related traits and on the neurotransmitters and neuromodulators required.

Sex differences within sleep in gonadally intact rats

Sleep impacts diverse physiological and neural processes and is itself affected by the menstrual cycle; however, few studies have examined the effects of the estrous cycle on sleep in rodents. Studies of disease mechanisms in females therefore lack critical information regarding estrous cycle influences on relevant sleep characteristics. We recorded electroencephalographic (EEG) activity from multiple brain regions to assess sleep states as well as sleep traits such as spectral power and interregional spectral coherence in freely cycling females across the estrous cycle and compared with males. Our findings show that the high hormone phase of proestrus decreases the amount of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep and increases the amount of time spent awake compared with other estrous phases and to males. This spontaneous sleep deprivation of proestrus was followed by a sleep rebound in estrus which increased NREM and REM sleep. In proestrus, spectral power increased in the delta (0.5-4 Hz) and the gamma (30-60 Hz) ranges during NREM sleep, and increased in the theta range (5-9 Hz) during REM sleep during both proestrus and estrus. Slow-wave activity (SWA) and cortical sleep spindle density also increased in NREM sleep during proestrus. Finally, interregional NREM and REM spectral coherence increased during proestrus. This work demonstrates that the estrous cycle affects more facets of sleep than previously thought and reveals both sex differences in features of the sleep-wake cycle related to estrous phase that likely impact the myriad physiological processes influenced by sleep.

Sleep Changes Across the Female Hormonal Cycle Affecting Memory: Implications for Resilient Adaptation to Traumatic Experiences

We review findings and propose a model explaining why women's adaptation to traumatic stress might be different than men's, including the role of cycling hormones and sleep differences in the development of post-traumatic stress and other stress-related disorders. Women are diagnosed with stress-related mental health disorders at a higher frequency than men. Most mental health disorders involve sleep disturbances, which may contribute to these disorders. The mechanisms by which sleep contributes to the development of mental health disorders in women have not been addressed in basic research. Sleep features such as spindle density and rapid eye movement (REM) sleep theta power are important for the role of sleep in emotion and cognition. The effect of hormonal cycles on these and other critical sleep features is only beginning to be understood. We explore what sleep factors could confer resilience to mental health disorders and how they might be altered by hormonal cycles in women. We target a specific system at the nexus of arousal control, stress response, and memory consolidation processes that has not been explored at all in women or across the hormonal cycle in animal studies: the locus coeruleus noradrenergic (LC-NE) system.

Endometrioid adenocarcinoma of the ovary and endometriosis

OBJECTIVE

We present a retrospective analysis of 22 cases of endometrioid ovarian carcinoma, reviewed to identify endometriosis and its malignant transformation.

STUDY DESIGN

Twenty-two patients with endometrioid ovarian cancer were included in the review. Their clinical and histological data were retrospectively reviewed. The origin of the tumours was considered endometriosis-related when the presence of malignant changes in endometriosis glands leading to endometrioid carcinoma were found.

RESULTS

Endometriosis was detected in three cases (3/22=14%). One of them presented a clearly benign to malignant transformation area. In another patient, the transition zone was abrupt and present in both ovaries. In the third, a pre-menopausal woman, ovarian endometriosis with only focal endometrioid carcinoma was observed. The three of them had a clear-cell carcinoma component. The presence of a clear-cell component was significantly greater in patients with endometriosis than in patients without endometriosis Each patient had a different clinical presentation: increase in abdominal perimeter, post-menopausal vaginal haemorrhage and hypermenorrhea. Preoperative CA 125 levels were avalaible in 15 of the patients (15/22=68%). Endometriosis was found in two of these 15 patients, both with the highest CA 125 measured levels, exceeding 1700 U/ml. In the remaining of the patients, CA 125 value did not exceed 35 U/ml.

CONCLUSION

Although this association is not very frequent, patients with ovarian endometriosis and a high CA 125 serum level should be managed with special care, regardless of their pre-menopausal or post-menopausal status.

Effectiveness of reminder systems on appointment adherence rates

The aim of this study was to determine the impact of reminder systems on appointment nonadherence rates in an low-income inner-city clinic population. A total of 2,304 consenting patients were randomly assigned to one of three groups: (1) automated telephone reminder, (2) postcard reminder, or (3) no reminder. In contrast with research on other populations, the results of this study demonstrated no significant difference in appointment adherence rates among the three groups. To aid in the development of more effective interventions in the future, individuals not attending their scheduled appointments were interviewed by telephone to determine reason for nonadherence.

The impact of depressive symptoms on the functional status of inner-city patients with asthma

BACKGROUND

Functional deficits are common in patients with asthma. If there is cooccurring depression, these deficits may be more severe and/or more persistent.

OBJECTIVE

This study was undertaken to determine 1) the prevalence and severity of depressive symptoms in a sample of inner-city patients being treated for asthma and 2) the impact of these symptoms on functional status.

METHODS

Three hundred seventeen enrollees in an inner-city asthma program were evaluated using the health status questionnaire and the Center for Epidemiologic Studies Depression Scale (CES-D) at baseline and at 3- and 6-month follow-ups. Two groups were created based on patients' CES-D baseline scores, using a commonly used cutpoint to define "caseness" for depression. The two groups were compared using ANOVA, chi2, and the general linear model for repeated measures.

RESULTS

Of the sample, 55.01% had a CES-D score greater than the cutpoint for depression. The mean was 29.3 +/- 11.95, well above the scores commonly used to indicate the presence of depression. The depressed group had lower scores on many measures of functional capacity at baseline; whereas both depressed and nondepressed patients improved over time on the physical performance measure (the physical performance measure subscale of the health status questionnaire), the mean score for the depressed group was consistently lower.

CONCLUSIONS

The prevalence of depressive symptoms was greater than expected. Depression was persistent and had a major impact on functional capacity. Routine depression screening may be especially important in inner-city patients and other groups thought to be at increased risk for poor outcome.

The toxicity of the daily intake of nitrite and dimethylamine

It is known that sodium nitrite and dimethylamine are toxic compounds, which may react to form dimethylnitrosamine in the gastro-intestinal tract, a much more toxic compound and a powerful cancerogen. The aim of the present work is the investigation of toxicity in young rats, caused by daily intake of sodium nitrite, administered together with dimethylamine during 30 days. The indicators examined were: histopathological analysis of the liver and kidney, transaminase in blood serum, variations in body weight and relation of weight liver/body weight. The method of analysis used to determine transaminase was that reported by Reintman and Frankel in 1957. The statistical method employed was the test of multiple comparisons based on the total ranges of Cruskal-Wallis. The results show that either significant differences were found (alpha = 0,05) among the groups (including the control), nor was necrosis observed or forming of tumors in the organs under investigation. Therefore, the doses administered does not seem to be toxic under the conditions of the experiment. Some signs of toxicity found in the group which was severely treated (10 mg of sodium nitrite and 20 mg of dimethylamine) appeared only in a few animals and it is necessary to verify the same in experiments with more animals and over a longer period of treatment.