Vous êtes ici : Accueil > Actualités > diabete et sommeil / rôles de la melanopsine / troubles ophtalmiques et SAOS/ modafinil et activation corticale / mémoire déclarative et temps de sommeil

diabete et sommeil / rôles de la melanopsine / troubles ophtalmiques et SAOS/ modafinil et activation corticale / mémoire déclarative et temps de sommeil

Sommeil et troubles ophtalmiques
Le syndrome d’apnées obstructives du sommeil est passible d’entraîner des troubles ophtalmologiques. C’est ce sur quoi une revue de la littérature parue dans Current Opinions in Ophtalmology a voulu attirer l’attention. Un traitement précoce du SAOS est préconisé pour réduire le risque de complications systémiques irréversibles et préserver les fonctions visuelle et oculaire. Le recueil de  données longitudinales probantes est attendu qui devrait permettre d’évaluer sur le long terme les bénéfices d’une prise en charge des apnées du sommeil et des ronflements et son impact sur les complications associées qui sont réversibles.
 
Chronobiologie
Une revue de la littérature parue dans Trends Molecular Medicine  (30 août 2010)  met en évidence les différentes fonctions de la mélanopsine et des cellules ganglionnaires photosensibles de la rétine sur l’adaptabilité à l’intensité lumineuse ambiante comme susceptibles d’ouvrir des perspectives pharmacologiques probantes et de permettre une amélioration sensible de la qualité de vie.
 
Pharmacologie
Une étude randomisée contrôlée contre placebo en double aveugle vient caractériser les effets du modafinil sur l’excitation corticale de patients atteints de narcolepsie avec cataplexie, en utilisant la technique de la stimulation magnétique transcranienne. Cette étude est parue dans la revue Sleep Medicine(30 août 2010)
 
Sommeil et métabolisme
Les corrélations entre troubles du sommeil et diabète de type 1 et 2 sont l’objet d’une revue de la littérature parue dans Diabetes Research Clinical Practice (30 août 2010). Cette revue entend caractériser plus spécifiquement la médiation neuro-endocrino-métabolique responsable du cercle vicieux observé entre sommeil contrarié et troubles diabétiques et inversement en fonction des deux types de diabètes.
 
Neurosciences
Une étude parue dans la revue PloS One( août 2010 12;5(8). pii: e12131) explore la nature temporelle des facteurs tels le processus d’éveil et les processus d’augmentation homéostatique du sommeil sur la processus de rétention de la mémoire déclarative.
 
Les veilles bibliographiques précédentes sont archivées sur le site web de la SFRMS, ici même
 
Bien sincèrement,
Cécile Cornibert
 -----
Current Opinions in Ophthalmology. 2010 Sep 1. [Epub ahead of print]
Obstructive sleep apnea and ocular disorders.
Grover DP.
Department of Neuro-Ophthalmology, Wills Eye Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Abstract
PURPOSE OF REVIEW: Obstructive sleep apnea is a diagnosis that ophthalmologists can screen for when a patient presents with certain risk factors. Recent literature provides strong data for associations between sleep apnea and ocular disorders.
RECENT FINDINGS: A potentially serious disorder, sleep apnea can lead to many systemic and ocular complications. Recent findings provide data on the prevalence of sleep apnea with various disorders. Adequate treatment of sleep apnea has also shown to reverse both systemic and eye-related complications.
SUMMARY: Early diagnosis and management of sleep apnea is critical for reducing the risk of devastating systemic complications and preserving ocular and visual function. Further longitudinal data are needed to see the effectivity of long-term management of sleep apnea and its impact on reversing associated complications.
PMID: 20811281 [PubMed - as supplied by publisher]
---
Trends Molecular Medicine. 2010 Aug 30. [Epub ahead of print]
The emerging roles of melanopsin in behavioral adaptation to light.
Hatori M, Panda S.
The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Abstract
The adaptation of behavior and physiology to changes in the ambient light level is of crucial importance to life. These adaptations include the light modulation of neuroendocrine function and temporal alignment of physiology and behavior to the day:night cycle by the circadian clock. These non-image-forming (NIF) responses can function independent of rod and cone photoreceptors but depend on ocular light reception, suggesting the participation of novel photoreceptors in the eye. The discovery of melanopsin in intrinsically photosensitive retinal ganglion cells (ipRGCs) and genetic proof for its important role in major NIF responses have offered an exciting entry point to comprehend how mammals adapt to the light environment. Here, we review the recent advances in our understanding of the emerging roles of melanopsin and ipRGCs. These findings now offer new avenues to understand the role of ambient light in sleep, alertness, dependent physiologies and potential pharmacological intervention as well as lifestyle modifications to improve the quality of life.
PMID: 20810319 [PubMed - as supplied by publisher]
----
Sleep Medicine. 2010 Aug 30. [Epub ahead of print]
The effect of modafinil on cortical excitability in patients with narcolepsy: A randomized, placebo-controlled, crossover study.
Joo EY, Kim HJ, Lim YH, Koo DL, Ji KH, Hong SB.
Sleep Center, Department of Neurology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea.
Abstract
OBJECTIVE: To investigate the effect of modafinil on cortical excitability in patients with narcolepsy using transcranial magnetic stimulation (TMS).
METHODS: Nineteen drug-naïve narcolepsy patients with cataplexy (10 males, 9 females, and mean age 28.5years) and 25 age- and sex-matched healthy controls were recruited. In this double-blind, randomized, crossover study, patients and controls received a single dose of 400mg modafinil or placebo. Modafinil and placebo administrations were separated by a 2-week washout period. TMS parameters, such as resting motor thresholds (RMT), motor-evoked potential (MEP) amplitudes, cortical silent periods (CSP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF), were measured before and 3h after administering modafinil or placebo. The differences of TMS parameters were statistically tested between patients and controls and between before and after modafinil or placebo administration.
RESULTS: Narcolepsy patients had significantly increased CSP durations compared to controls (independent t-test, P<0.05), indicating decreased excitability of cortical networks in human narcolepsy. In patients after modafinil administration, MEP amplitudes, SICI, and ICF increased, and CSP duration shortened significantly, meaning enhanced motor excitability, whereas in controls modafinil did not change TMS parameters significantly. Placebo administration did not affect TMS parameters both in patients or controls.
CONCLUSIONS: Narcolepsy patients with cataplexy showed decreased cortical excitability than normal healthy controls. Single dose modafinil significantly increased motor excitability in narcolepsy patients but had no effect in healthy controls.
PMID: 20810312 [PubMed - as supplied by publisher]
----
Diabetes Research Clinical Practice. 2010 Aug 30. [Epub ahead of print]
Diabetes and sleep: A complex cause-and-effect relationship.
Barone MT, Menna-Barreto L.
Instituto de Ciências Biomédicas, Universidade de São Paulo (ICB-USP), Brazil.
Abstract : Strong associations of diabetes with sleep impairment have been frequently reported. In the present review, we discuss current evidence and hypotheses for how type 1 and type 2 diabetes mellitus are associated with sleep impairment. This association may be described as a vicious circle, where sleep disorders favor the development of type 2 diabetes or exacerbate the metabolic control of both types of diabetes, whereas diabetes itself, especially when associated with poor metabolic control, is often followed by sleep disorders. In this review, novel findings concerning the neuro-endocrine-metabolic mediation of the mentioned circle are highlighted. Understanding how this association occurs, the impact of sleep impairment on diabetes, and the impact of diabetes on the development or exacerbation of sleep disorders should lead to potential new therapeutic strategies for treating both conditions.
PMID: 20810183 [PubMed - as supplied by publisher]
---
PLoS One. 2010 Aug 12;5(8). pii: e12131.
Delayed onset of a daytime nap facilitates retention of declarative memory.
Alger SE, Lau H, Fishbein W.
Cognitive Neuroscience Subprogram, Department of Psychology, The City College of the City University of New York, New York, New York, United States of America.
Abstract
BACKGROUND: Learning followed by a period of sleep, even as little as a nap, promotes memory consolidation. It is now generally recognized that sleep facilitates the stabilization of information acquired prior to sleep. However, the temporal nature of the effect of sleep on retention of declarative memory is yet to be understood. We examined the impact of a delayed nap onset on the recognition of neutral pictorial stimuli with an added spatial component.
METHODOLOGY/PRINCIPAL FINDINGS: Participants completed an initial study session involving 150 neutral pictures of people, places, and objects. Immediately following the picture presentation, participants were asked to make recognition judgments on a subset of "old", previously seen, pictures versus intermixed "new" pictures. Participants were then divided into one of four groups who either took a 90-minute nap immediately, 2 hours, or 4 hours after learning, or remained awake for the duration of the experiment. 6 hours after initial learning, participants were again tested on the remaining "old" pictures, with "new" pictures intermixed.
CONCLUSIONS/SIGNIFICANCE: Interestingly, we found a stabilizing benefit of sleep on the memory trace reflected as a significant negative correlation between the average time elapsed before napping and decline in performance from test to retest (p = .001). We found a significant interaction between the groups and their performance from test to retest (p = .010), with the 4-hour delay group performing significantly better than both those who slept immediately and those who remained awake (p = .044, p = .010, respectively). Analysis of sleep data revealed a significant positive correlation between amount of slow wave sleep (SWS) achieved and length of the delay before sleep onset (p = .048). The findings add to the understanding of memory processing in humans, suggesting that factors such as waking processing and homeostatic increases in need for sleep over time modulate the importance of sleep to consolidation of neutral declarative memories.
PMID: 20808821 [PubMed - in process]

Tél : 01 42 66 45 85

du Lundi au Vendredi

de 9h à 19h

72 boulevard de Courcelles

75017 PARIS

Métro Courcelles

Recherche sur le site


Groupe Santé Sommeil

Le groupe médical Santé Sommeil a pour vocation de diagnostiquer et traiter les troubles du sommeil et de la veille chez l’adulte et l’enfant.