Mood Influences the Concordance of Subjective and Objective Measures of Sleep Duration in Older Adults

Objective/Background: Sleep plays a central role in maintaining health and cognition. In most epidemiologic studies, sleep is evaluated by self-report questionnaires but several reports suggest that these evaluations might be less accurate than objective measures such as polysomnography or actigraphy. Determinants of the discrepancy between objective and subjective measures remain to be investigated. The aim of this pilot-study was to examine the role of mood states in determining the discrepancy observed between objective and subjective measures of sleep duration in older adults.Patients/Methods: Objective sleep quantity and quality were recorded by actigraphy in a sample of 45 elderly subjects over at least three consecutive nights. Subjective sleep duration and supplementary data, such as mood status and memory, were evaluated using Ecological Momentary Assessment (EMA).Results: A significant discrepancy was observed between EMA and actigraphic measures of sleep duration (p<0.001). The magnitude of this difference was explained by the patient’s mood status (p=0.020). No association was found between the magnitude of this discrepancy and age, sex, sleep quality or memory performance.Conclusion: The discrepancy classically observed between objective and subjective measures of sleep duration can be explained by mood status at the time of awakening. These results have potential implications for epidemiologic and clinical studies examining sleep as a risk factor for morbidity or mortality

Activity/rest cycle and disturbances of structural backbone of cerebral networks in aging.

OBJECTIVE: Although aging is associated with alterations of both activity/rest cycle and brain structure, few studies have evaluated associations between these processes. The aim of this study was to examine relationship between activity/rest cycle quality and brain structural integrity in aging subjects by exploring both grey and white matter compartments. MATERIAL AND METHODS: Fifty-eight elderly subjects (76±0.5 years; 41% female) without dementia, sleep disorders and medications were included in the analysis. Actigraphy was used to measure parameters of activity/rest cycle (24-h amplitude, 24-h fragmentation and 24-h stability) and sleep (total sleep time and sleep fragmentation) over a minimal period of 5 days. Whole brain linear regression analyses were performed on grey matter volumes maps using voxel based morphometry and on white matter integrity using tract based statistics analyses. RESULTS: A lower 24-h amplitude and a higher sleep fragmentation were independently associated with a reduction of white matter integrity in models including age and gender as covariates. The association between 24-h amplitude and white matter integrity decreased but remained significant in a model accounted for sleep fragmentation, indicating a specific effect of 24-h cycle disturbances. No association with grey matter volumes was observed. CONCLUSION: In elderly, not only sleep but also 24-h cycle disturbances were associated with altered structural connectivity. This alteration of structural backbone networks related to activity/rest cycle disturbances in aging might constitute a cerebral frailty factor for the development of cognitive impairment

A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1.We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K⁠, R⋆=0.726±0.007R⊙⁠, and M⋆=0.748±0.032M⊙⁠. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.Publisher PDFPeer reviewe

Le noyau basal magnocellulaire chez le rat : etude anatomo-biochimique et comportementale

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Assessment of dream-related aspects and beliefs in a large cohort of French students using a validated French version of the Mannheim Dream questionnaire.

Focusing on a specific population when studying dream characteristics can shed light on underlying mechanisms and correlates of dreaming. The aim of this study is to establish a clearer description of specific dream aspects and beliefs in a large cohort of students using a validated questionnaire, and to further investigate the role of sociodemographic variables such as age, gender and field of study. Participants were 1137 students aged from 18 to 34 (mean age: 22.2) who responded to an online version of the questionnaire. Our results showed a difference between humanities and science students, and a differential effect of gender on dream variables. Our results are discussed in light of previous investigations using the same questionnaire or focusing on the same population

Neurosteroids and cholinergic systems: implications for sleep and cognitive processes and potential role of age-related changes

International audienceThe neurosteroids pregnenolone sulfate (PREGS), dehydroepiandrosterone sulfate (DHEAS) and allopregnanolone (3alpha,5alpha THPROG) have been implicated as powerful modulators of memory processes and sleep states in young and aged subjects with memory impairment. As these processes depend on the integrity of cholinergic systems, a specific effect of neurosteroids on these systems may account for their effects on sleep and memory

The age-related positivity effect: forgetting the negative and/or remembering the positive? An inter-task study

De nombreuses études ont révélé que les adultes âgés ont tendance à mieux mémoriser les informations positives que les informations négatives, lorsqu’on les compare à des adultes jeunes. Notre objectif était de déterminer si cet effet de positivité lié à l’âge dépend d’une meilleure mémorisation des informations positives et/ou d’une moins bonne mémorisation des informations négatives chez les adultes âgés comparativement aux adultes jeunes dans différentes tâches mnésiques. Quatre-vingt-dix participants (45 adultes jeunes, 45 adultes âgés) ont effectué des tâches de rappel immédiat, de reconnaissance et de rappel différé. Les participants devaient apprendre des mots positifs, négatifs et neutres. Les résultats ont montré que l’effet de positivité lié à l’âge dépendait uniquement de la diminution de la préférence pour la négativité (i.e. la comparaison entre les mots négatifs et neutres) chez les adultes âgés. Cet effet était présent en rappel libre mais pas en reconnaissance. Par ailleurs, dans la tâche de rappel immédiat, plus les adultes âgés avaient de bonnes compétences mnésiques moins leur préférence pour la négativité était élevée. Ce lien n’était pas présent en rappel différé. Ces données suggèrent que, comparativement aux adultes jeunes, les adultes âgés se désengagent du traitement des mots négatifs sur la base de processus cognitifs coûteux. Ces résultats sont discutés dans le cadre de la théorie de la sélectivité socio-émotionnelle.A growing number of studies have shown that, compared to young adults, older adults better remember positive information than negative information. However, it is not clear whether this age-related positivity effect relies on an increase in positive information memory and/or on a decrease in negative information memory. Thus, we aimed to study the specific mechanisms underlying the age-related positivity effect in different memory tasks. To do so, we used an emotional word memory paradigm including immediate free recall, recognition and delayed free recall tasks. Forty-five young adults (m = 20.0 years) and 45 older adults (m = 69.2 years) native French speakers participated. Thirty-six low French words, including 12 negative (e.g. égout), 12 positive (e.g. lagune) and 12 neutral (e.g. notion) words were selected from an emotional lexical database (Gobin et al. 2017). For the recognition task, 36 new words were selected. The results showed that the age-related positivity effect specifically depended on a decrease in negativity preference (i.e. the comparison between negative and neutral words) in older adults, in comparison with young adults, both in immediate and delayed free recall tasks. Indeed, in these tasks, young adults recalled more negative than neutral words whereas there was no difference in older adults. In recognition task, no age-related positivity effect has been observed. Moreover, the results showed that, in immediate recall, the higher the older adults memory abilities, the lower their negativity preference. This correlation was not significant in delayed recall. These results suggest that, when compared with young adults, older adults disengage from negative words processing through costly cognitive processes. A small magnitude of negativity preference would indicate good maintenance of memory abilities. Results are discussed in the framework of the socioemotional selectivity theory

Psychol Aging

The age-related positivity effect is the tendency of older adults to preferentially process positive information over negative information when compared to younger adults (e.g., Reed & Carstensen, 2012). The aim of the study was to determine whether common and/or distinct mechanisms underlie the age-related positivity effect in lexical access and episodic memory. Fifty young and 50 older adults successively performed a progressive demasking task incorporating memory instructions, an immediate free recall task, a memory recognition task, and delayed free recalls at 20 min and 7 days. The materials included 60 words that varied in emotional valence (positive, neutral, negative) and arousal (low, high). The results revealed that distinct processes underlie the age-related positivity effect in lexical access and episodic memory. In progressive demasking, this effect emerged for both low- and high-arousal words, suggesting that it depends on automatic processes. In immediate and delayed free recall and recognition, this effect emerged for low-arousal words only, suggesting that it depends on more controlled processes. Moreover, in older adults, positivity scores correlated with well-being scores for episodic memory. These results are discussed in relation to affective aging theories. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

Neuroactive steroids: new biomarkers of cognitive aging

International audienceIntensive studies in animals established that neuroactive steroids display neuronal actions and influence behavioral functions. We describe here investigations on the role of neuroactive steroids in learning and memory processes during aging and suggest their role as biomarkers of cognitive aging. Our work demonstrated the role of the steroid pregnenolone (PREG) sulfate as a factor underlying an individual's age-related cognitive decline in animals. As new perspectives of research we argue that knowing whether neuroactive steroids exist as endogenous neuromodulators and modulate physiologically behavioral functions is essential. To this end, a new approach using the sensitive, specific, and accurate quantitative determination of neuroactive steroids by mass spectrometry seems to have potential for examining the role of each steroid in discrete brain areas in learning and memory alterations, as observed during aging

Long-term effects of prenatal stress and handling on metabolic parameters: relationship to corticosterone secretion response

International audienceThe prenatal and postnatal environment exerts a long-term influence on the stress-response of the hypothalamic-pituitary-adrenal (HPA) axis. In this study, the long-term effects of prenatal and postnatal manipulations and their related changes on glucocorticoid secretion were examined on metabolic parameters in adult rats. Plasma glucose levels, body weight and basal feeding behavior were measured. We show that modifications of the prenatal and postnatal environment have opposite long-term effects on these parameters, except for blood glucose, which was increased in prenatally stressed animals. Although the mechanisms underlying these phenomena remain to be elucidated, the observations show that perinatal manipulations have long-term effects on metabolic functions related to HPA activity