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Vallières A, Pappathomas A, Garnier SDB, Mérette C, Carrier J, Paquette T, Bastien CH. Behavioural therapy for shift work disorder improves shift workers' sleep, sleepiness and mental health: A pilot randomised control trial. J Sleep Res 2024:e14162. [PMID: 38443322 DOI: 10.1111/jsr.14162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 03/07/2024]
Abstract
The present study evaluates the efficacy of behavioural therapy adapted for shift work disorder with a randomised control design in a healthcare population. Forty-three night shift workers (m. age: 34 years; 77% women) experiencing shift work disorder were randomised to either the behavioural therapy for shift work disorder (BT-SWD) or a waiting-list control group offered after the waiting period. Participants completed questionnaires on insomnia, sleepiness and mental health pre- and post-treatment, pre- and post-waiting, and at follow-up, and a sleep diary. As night shift workers alternate between sleeping during the day after their night shifts and transitioning to nighttime sleep on days off, insomnia severity and sleep variables were analysed for daytime and nighttime sleep. The BT-SWD involved sleep restriction therapy, stimulus control and fixed sleep periods in the dark. Statistical analyses were performed under intent-to-treat and per-protocol approaches. Repeated-measures two-way ANCOVA analysis, controlling for age, sex and pre-treatment daytime total sleep time, was performed with Bonferroni corrections, and between-group effect sizes computed. Fourteen participants dropped out after randomisation. Under the intent-to-treat analysis, BT-SWD participants had a significant greater decrease in daytime insomnia severity and an increase in daytime total sleep time at post-treatment than the control group, with large between-group effect sizes (-1.25 and 0.89). These corresponding results were also significant with large effect sizes under the per-protocol analysis. Sleepiness, anxiety and depression levels improved at post-treatment and maintained at follow-up when the BT-SWD treated controls were added to the BT-SWD group. The behavioural therapy for shift work disorder can be used to improve the sleep and mental health of healthcare night workers.
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Affiliation(s)
- Annie Vallières
- École de psychologie, Université Laval, Québec, Québec, Canada
- Centre de recherche CERVO, Québec, Québec, Canada
- Centre de recherche du Centre hospitalier universitaire de Québec-Université Laval, Québec, Québec, Canada
| | - Alric Pappathomas
- École de psychologie, Université Laval, Québec, Québec, Canada
- Centre de recherche CERVO, Québec, Québec, Canada
- Centre de recherche du Centre hospitalier universitaire de Québec-Université Laval, Québec, Québec, Canada
| | | | - Chantal Mérette
- Centre de recherche CERVO, Québec, Québec, Canada
- Département de psychiatrie et de neurosciences, Faculté de médecine, Université Laval, Québec, Québec, Canada
| | - Julie Carrier
- Département de psychologie, Université de Montréal, Montréal, Québec, Canada
- Centre d'étude avancée en médecine du sommeil, CIUSSS-NIM, Montréal, Québec, Canada
| | - Tyna Paquette
- Centre d'étude avancée en médecine du sommeil, CIUSSS-NIM, Montréal, Québec, Canada
| | - Célyne H Bastien
- École de psychologie, Université Laval, Québec, Québec, Canada
- Centre de recherche CERVO, Québec, Québec, Canada
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Picard-Deland C, Aumont T, Samson-Richer A, Paquette T, Nielsen T. Whole-body procedural learning benefits from targeted memory reactivation in REM sleep and task-related dreaming. Neurobiol Learn Mem 2021; 183:107460. [PMID: 34015442 DOI: 10.1016/j.nlm.2021.107460] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/20/2021] [Accepted: 05/12/2021] [Indexed: 10/21/2022]
Abstract
Sleep facilitates memory consolidation through offline reactivations of memory traces. Dreaming may play a role in memory improvement and may reflect these memory reactivations. To experimentally address this question, we used targeted memory reactivation (TMR), i.e., application, during sleep, of a stimulus that was previously associated with learning, to assess whether it influences task-related dream imagery (or task-dream reactivations). Specifically, we asked if TMR or task-dream reactivations in either slow-wave (SWS) or rapid eye movement (REM) sleep benefit whole-body procedural learning. Healthy participants completed a virtual reality (VR) flying task prior to and following a morning nap or rest period during which task-associated tones were readministered in either SWS, REM sleep, wake or not at all. Findings indicate that learning benefits most from TMR when applied in REM sleep compared to a Control-sleep group. REM dreams that reactivated kinesthetic elements of the VR task (e.g., flying, accelerating) were also associated with higher improvement on the task than were dreams that reactivated visual elements (e.g., landscapes) or that had no reactivations. TMR did not itself influence dream content but its effects on performance were greater when coexisting with task-dream reactivations in REM sleep. Findings may help explain the mechanistic relationships between dream and memory reactivations and may contribute to the development of sleep-based methods to optimize complex skill learning.
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Affiliation(s)
- Claudia Picard-Deland
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Neuroscience, Université de Montréal, Montréal, Québec, Canada
| | - Tomy Aumont
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Arnaud Samson-Richer
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tyna Paquette
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tore Nielsen
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Psychiatry and Addictology, Université de Montréal, Montréal, Québec, Canada.
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Marquis LP, Julien SH, Daneault V, Blanchette-Carrière C, Paquette T, Carr M, Soucy JP, Montplaisir J, Nielsen T. Local Neuronal Synchronization in Frequent Nightmare Recallers and Healthy Controls: A Resting-State Functional Magnetic Resonance Imaging Study. Front Neurosci 2021; 15:645255. [PMID: 33815047 PMCID: PMC8012764 DOI: 10.3389/fnins.2021.645255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/25/2021] [Indexed: 11/25/2022] Open
Abstract
Nightmares are highly dysphoric dreams that are well-remembered upon awakening. Frequent nightmares have been associated with psychopathology and emotional dysregulation, yet their neural mechanisms remain largely unknown. Our neurocognitive model posits that nightmares reflect dysfunction in a limbic-prefrontal circuit comprising medial prefrontal and anterior cingulate cortices, hippocampus, and amygdala. However, there is a paucity of studies that used brain imaging to directly test the neural correlates of nightmares. One such study compared the regional homogeneity (ReHo) of resting-state functional magnetic resonance imaging blood-oxygen level-dependent signals between frequent nightmare recallers and controls. The main results were greater regional homogeneity in the left anterior cingulate cortex and right inferior parietal lobule for the nightmare recallers than for the controls. In the present study, we aimed to document the ReHo correlates of frequent nightmares using several nightmare severity measures. We acquired resting-state functional magnetic resonance imaging data from 18 frequent nightmare recallers aged 18-35 (3 males and 15 females) and 18 age- and sex-matched controls, as well as retrospective and prospective disturbed dreaming frequency estimates and scores on the Nightmare Distress Questionnaire. While there were inconsistent results for our different analyses (group comparisons, correlational analyses for frequency estimates/Nightmare Distress scores), our results suggest that nightmares are associated with altered ReHo in frontal (medial prefrontal and inferior frontal), parietal, temporal and occipital regions, as well as some subcortical regions (thalamus). We also found a positive correlation between retrospective disturbed dreaming frequency estimates and ReHo values in the hippocampus. These findings are mostly in line with a recent SPECT study from our laboratory. Our results point to the possibility that a variety of regions, including but not limited to the limbic-prefrontal circuit of our neurocognitive model, contribute to nightmare formation.
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Affiliation(s)
- Louis-Philippe Marquis
- Department of Psychology, Université de Montréal, Montreal, QC, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Sarah-Hélène Julien
- Department of Psychology, Université de Montréal, Montreal, QC, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Véronique Daneault
- Department of Psychology, Université de Montréal, Montreal, QC, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Cloé Blanchette-Carrière
- Department of Psychology, Université de Montréal, Montreal, QC, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
| | - Michelle Carr
- Department of Psychiatry, Sleep & Neurophysiology Research Laboratory, University of Rochester Medical Center, Rochester, NY, United States
| | | | - Jacques Montplaisir
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
- Department of Psychiatry, Université de Montréal, Montreal, QC, Canada
| | - Tore Nielsen
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada
- Department of Psychiatry, Université de Montréal, Montreal, QC, Canada
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Picard-Deland C, Pastor M, Solomonova E, Paquette T, Nielsen T. Flying dreams stimulated by an immersive virtual reality task. Conscious Cogn 2020; 83:102958. [DOI: 10.1016/j.concog.2020.102958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/27/2020] [Accepted: 05/18/2020] [Indexed: 12/01/2022]
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Blanchette-Carrière C, Julien SH, Picard-Deland C, Bouchard M, Carrier J, Paquette T, Nielsen T. Attempted induction of signalled lucid dreaming by transcranial alternating current stimulation. Conscious Cogn 2020; 83:102957. [PMID: 32534325 DOI: 10.1016/j.concog.2020.102957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/17/2020] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
Neurophysiological correlates of self-awareness during sleep ('lucid dreaming') remain unclear despite their importance for clarifying the neural underpinnings of consciousness. Transcranial direct (tDC) and alternating (tAC) current stimulation during sleep have been shown to increase dream self-awareness, but these studies' methodological weaknesses prompted us to undertake additional study. tAC stimulation was associated with signal-verified and self-rated lucid dreams-but so was the sham procedure. Situational factors may be crucial to inducing self-awareness during sleep.
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Affiliation(s)
- Cloé Blanchette-Carrière
- Department of Psychiatry, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Sarah-Hélène Julien
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Claudia Picard-Deland
- Department of Neurosciences, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Maude Bouchard
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Julie Carrier
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Tore Nielsen
- Department of Psychiatry, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada.
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Picard-Deland C, Pastor M, Solomonova E, Paquette T, Nielsen T. 0088 Gravity Dreams Following a Virtual Reality Flight Simulation. Sleep 2020. [DOI: 10.1093/sleep/zsaa056.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Introduction
Flying is a prevalent but infrequent experience in dreams. Despite a broad interest in such unique dream experiences, there is still no experimental procedure for reliably inducing them. Our study aimed 1) to induce flying dreams in the laboratory using virtual reality (VR), 2) to examine phenomenological correlates of flying dreams, such as lucidity and emotions and 3) to investigate the dynamics of dreamed gravity imagery in relation to participant state and trait factors.
Methods
A total of 137 healthy participants (24.01±4.03 y.o.; 85 F; 52 M) took part in a custom-built immersive VR task in which they learn how to ‘fly’ as precisely and quickly as possible, engaging vestibular, motor and visuo-spatial systems. Dreams were collected a) from home dream journals for 5 days before and 10 days after the laboratory VR task and b) after a 90-min morning nap in laboratory. Dream reports were scored by 2 independent judges for flying and other gravity-related imagery. Linear mixed models statistics were used to compare dreams from this cohort with a separate control cohort (N=52) that followed a similar protocol in the same lab but did not undertake a virtual flying task.
Results
The VR task successfully increased the likelihood of experiencing flying in dreams from both the laboratory nap (7.1%) and the following night (10.6%) compared to baseline (1.3%) and the control cohort on those days (Lab: 2.4%; following night: 0%). In contrast, the occurrence of other gravity imagery showed no differences. Flying dreams were altered qualitatively, exhibiting higher levels of lucid-control and emotional intensity after VR exposure. Moreover, various factors such as sex, prior dream experiences and sensory immersion in VR differentially modulated flying dream induction.
Conclusion
Our findings provide both quantitative and qualitative insights into flying dreams that may facilitate understanding of these typical dream experiences and future developments in dream flight-induction technologies.
Support
Natural Sciences and Engineering Research Council of Canada
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Affiliation(s)
- C Picard-Deland
- Université de Montréal, Neuroscience Department, Montreal, QC, CANADA
| | - M Pastor
- Dream & Nightmare Laboratory; Center for Advanced Research in Sleep Medicine, Montreal, QC, CANADA
| | - E Solomonova
- McGill University; Department of Psychiatry, Montreal, QC, CANADA
| | - T Paquette
- Dream & Nightmare Laboratory; Center for Advanced Research in Sleep Medicine, Montreal, QC, CANADA
| | - T Nielsen
- Dream & Nightmare Laboratory; Center for Advanced Research in Sleep Medicine, Montreal, QC, CANADA
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Solomonova E, Dubé S, Blanchette-Carrière C, Sandra DA, Samson-Richer A, Carr M, Paquette T, Nielsen T. Different Patterns of Sleep-Dependent Procedural Memory Consolidation in Vipassana Meditation Practitioners and Non-meditating Controls. Front Psychol 2020; 10:3014. [PMID: 32038390 PMCID: PMC6989470 DOI: 10.3389/fpsyg.2019.03014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 12/19/2019] [Indexed: 01/01/2023] Open
Abstract
Aim Rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep, and sleep spindles are all implicated in the consolidation of procedural memories. Relative contributions of sleep stages and sleep spindles were previously shown to depend on individual differences in task processing. However, no studies to our knowledge have focused on individual differences in experience with Vipassana meditation as related to sleep. Vipassana meditation is a form of mental training that enhances proprioceptive and somatic awareness and alters attentional style. The goal of this study was to examine a potential role for Vipassana meditation experience in sleep-dependent procedural memory consolidation. Methods Groups of Vipassana meditation practitioners (N = 22) and matched meditation-naïve controls (N = 20) slept for a daytime nap in the laboratory. Before and after the nap they completed a procedural task on the Wii Fit balance platform. Results Meditators performed slightly better on the task before the nap, but the two groups improved similarly after sleep. The groups showed different patterns of sleep-dependent procedural memory consolidation: in meditators, task learning was positively correlated with density of slow occipital spindles, while in controls task improvement was positively associated with time in REM sleep. Sleep efficiency and sleep architecture did not differ between groups. Meditation practitioners, however, had a lower density of occipital slow sleep spindles than controls. Conclusion Results suggest that neuroplastic changes associated with meditation practice may alter overall sleep microarchitecture and reorganize sleep-dependent patterns of memory consolidation. The lower density of occipital spindles in meditators may mean that meditation practice compensates for some of the memory functions of sleep.
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Affiliation(s)
- Elizaveta Solomonova
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada.,Department of Psychiatry, Université de Montréal, Montréal, QC, Canada.,Culture, Mind and Brain Research Group, Department of Psychiatry, McGill University, Montréal, QC, Canada
| | - Simon Dubé
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada.,Department of Psychology, Concordia University, Montréal, QC, Canada
| | - Cloé Blanchette-Carrière
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada
| | - Dasha A Sandra
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
| | - Arnaud Samson-Richer
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada
| | - Michelle Carr
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada.,Sleep Laboratory, Swansea University, Swansea, United Kingdom
| | - Tyna Paquette
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada
| | - Tore Nielsen
- Dream and Nightmare Laboratory, Centre for Advanced Research in Sleep Medicine, CIUSSS NÎM - HSCM, Montréal, QC, Canada.,Department of Psychiatry, Université de Montréal, Montréal, QC, Canada
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Nielsen T, Carr M, Picard-Deland C, Marquis LP, Saint-Onge K, Blanchette-Carrière C, Paquette T. Early childhood adversity associations with nightmare severity and sleep spindles. Sleep Med 2019; 56:57-65. [DOI: 10.1016/j.sleep.2019.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 12/22/2022]
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Marquis LP, Julien SH, Baril AA, Blanchette-Carrière C, Paquette T, Carr M, Soucy JP, Montplaisir J, Nielsen T. Nightmare Severity Is Inversely Related to Frontal Brain Activity During Waking State Picture Viewing. J Clin Sleep Med 2019; 15:253-264. [PMID: 30736883 DOI: 10.5664/jcsm.7628] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/24/2018] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES Growing evidence suggests that nightmares have considerable adverse effects on waking behavior, possibly by increasing post-sleep negative emotions. Dysphoric reactions to nightmares are one component of nightmare severity for which the neural correlates are unknown. Here, we investigate possible neural correlates of nightmare severity in a sample of individuals who frequently recall nightmares. METHODS Our principal measure of nightmare severity is nightmare distress as indexed by the Nightmare Distress Questionnaire (NDQ), and secondary measures are retrospective and prospective estimates of frequency of recalling dysphoric dreams (DD). We used high-resolution technetium 99m ethyl cysteinate dimer single photon emission computed tomography to assess regional cerebral blood flow (rCBF) while 18 individuals who were frequent nightmare recallers viewed negative and neutral pictures from the International Affective Picture System. We correlated rCBF with NDQ scores and DD recall frequency estimates. RESULTS Negative correlations were observed between NDQ scores and rCBF during negative picture viewing in bilateral insula and anterior cingulate, right medial frontal gyrus, bilateral superior temporal gyrus, right inferior frontal and precentral gyri, and bilateral putamen. Retrospective DD recall correlated with rCBF activity primarily in regions overlapping those related to NDQ scores. Prospective DD recall was only weakly related to rCBF. Results for the neutral condition overlapped partially with those for the negative condition; in particular, NDQ and retrospective DD recall were related to rCBF in medial prefrontal and anterior cingulate gyri. CONCLUSIONS Results point to a possible overlap in brain mechanisms involved in nightmare dysphoria (during sleep) and distress (during wakefulness) among individuals who frequently recall nightmares. They provide partial support for a neurocognitive model of nightmares. COMMENTARY A commentary on this article appears in this issue on page 179.
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Affiliation(s)
- Louis-Philippe Marquis
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada.,Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
| | - Sarah-Hélène Julien
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada.,Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
| | - Andrée-Ann Baril
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.,Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
| | - Cloé Blanchette-Carrière
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.,Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
| | - Michelle Carr
- Sleep Laboratory, Swansea University, Swansea, United Kingdom
| | | | - Jacques Montplaisir
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.,Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
| | - Tore Nielsen
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.,Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
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Solomonova E, Dubé S, Samson-Richer A, Blanchette-Carrière C, Paquette T, Nielsen T. Dream content and procedural learning in Vipassana meditators and controls. Dreaming 2018. [DOI: 10.1037/drm0000081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Carr M, Saint-Onge K, Blanchette-Carrière C, Paquette T, Nielsen T. Elevated perseveration errors on a verbal fluency task in frequent nightmare recallers: a replication. J Sleep Res 2017; 27:e12644. [DOI: 10.1111/jsr.12644] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 10/30/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Michelle Carr
- Dream and Nightmare Laboratory; Center for Advanced Research in Sleep Medicine; CIUSSS-NîM - Hôpital du Sacré-Coeur de Montréal; Montréal Québec Canada
- Swansea University Sleep Laboratory; Department of Psychology; Swansea University; Swansea UK
| | - Kadia Saint-Onge
- Dream and Nightmare Laboratory; Center for Advanced Research in Sleep Medicine; CIUSSS-NîM - Hôpital du Sacré-Coeur de Montréal; Montréal Québec Canada
- Department of Psychology; Université de Montréal; Montréal Québec Canada
| | - Cloé Blanchette-Carrière
- Dream and Nightmare Laboratory; Center for Advanced Research in Sleep Medicine; CIUSSS-NîM - Hôpital du Sacré-Coeur de Montréal; Montréal Québec Canada
- Department of Psychology; Université de Montréal; Montréal Québec Canada
| | - Tyna Paquette
- Dream and Nightmare Laboratory; Center for Advanced Research in Sleep Medicine; CIUSSS-NîM - Hôpital du Sacré-Coeur de Montréal; Montréal Québec Canada
| | - Tore Nielsen
- Dream and Nightmare Laboratory; Center for Advanced Research in Sleep Medicine; CIUSSS-NîM - Hôpital du Sacré-Coeur de Montréal; Montréal Québec Canada
- Department of Psychiatry; Université de Montréal; Montréal Québec Canada
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Abstract
Study Objectives To replicate and expand upon past research by evaluating sleep and wake electroencephalographic spectral activity in samples of frequent nightmare (NM) recallers and healthy controls. Methods Computation of spectral activity for sleep (non-REM and REM) and wake electroencephalogram recordings from 18 frequent NM recallers and 15 control participants. Results There was higher "slow-theta" (2-5 Hz) for NM recallers than for controls during wake, non-REM sleep and REM sleep. Differences were clearest for frontal and central derivations and for REM sleep cycles 2-4. There was also higher beta activity during NREM sleep for NM recallers. Findings partially replicate past research by demonstrating higher relative "slow-theta" (3-4Hz) for NM recallers than for controls. Conclusions Findings are consistent with a neurocognitive model of nightmares that stipulates cross-state anomalies in emotion processing in NM-prone individuals.
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Affiliation(s)
- Louis-Philippe Marquis
- Department of Psychology, Université de Montréal, Québec, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Cloé Blanchette-Carrière
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Québec, Canada
- Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Gaëlle Dumel
- Department of Psychology, Université de Montréal, Québec, Canada
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tore Nielsen
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Québec, Canada
- Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
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Marquis L, Julien S, Blanchette-Carrière C, Baril A, Desjardins M, Carr M, Paquette T, Soucy J, Montplaisir J, Nielsen T. 0732 NIGHTMARE DISTRESS IS NEGATIVELY CORRELATED WITH REGIONAL CEREBRAL BLOOD FLOW IN FRONTAL AREAS DURING AN IAPS PICTURE-VIEWING TASK. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Nielsen T, Carr M, Blanchette-Carrière C, Marquis LP, Dumel G, Solomonova E, Julien SH, Picard-Deland C, Paquette T. NREM sleep spindles are associated with dream recall. ACTA ACUST UNITED AC 2017. [DOI: 10.1556/2053.1.2016.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Tore Nielsen
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
| | - Michelle Carr
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Cloé Blanchette-Carrière
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Louis-Philippe Marquis
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada
| | - Gaëlle Dumel
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Psychology, Université du Québec à Montréal, Montréal, Québec, Canada
| | - Elizaveta Solomonova
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Sarah-Hélène Julien
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada
| | - Claudia Picard-Deland
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
- Department of Neurosciences, Université de Montréal, Montréal, Québec, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
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Dumel G, Carr M, Marquis LP, Blanchette-Carrière C, Paquette T, Nielsen T. Infrequent dream recall associated with low performance but high overnight improvement on mirror-tracing. J Sleep Res 2015; 24:372-82. [DOI: 10.1111/jsr.12286] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 01/27/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Gaëlle Dumel
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
- Department of Psychology; Université de Montréal; Montreal QC Canada
| | - Michelle Carr
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
- Department of Biomedical Sciences; Université de Montréal; Montreal QC Canada
| | - Louis-Philippe Marquis
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
- Department of Psychology; Université de Montréal; Montreal QC Canada
| | - Cloé Blanchette-Carrière
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
- Department of Psychology; Université de Montréal; Montreal QC Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
| | - Tore Nielsen
- Center for Advanced Research in Sleep Medicine; Hôpital du Sacré-Coeur de Montréal; Montreal QC Canada
- Department of Psychiatry; Université de Montréal; Montreal QC Canada
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Solomonova E, Paquette T, Stenstrom P, Nielsen T. W-O-116 DIFFERENT 10-DAY TEMPORAL PATTERNS OF DREAMS ABOUT SLEEP LABORATORY AND VIRTUAL REALITY MAZE EXPERIENCES: ASSOCIATIONS WITH TEMPORALLY PATTERNED CHANGES IN DREAMED LOCUS OF CONTROL. Sleep Med 2011. [DOI: 10.1016/s1389-9457(11)70463-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Nielsen T, Paquette T, Solomonova E, Lara-Carrasco J, Colombo R, Lanfranchi P. Changes in cardiac variability after REM sleep deprivation in recurrent nightmares. Sleep 2010; 33:113-22. [PMID: 20120628 DOI: 10.1093/sleep/33.1.113] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES To assess whether dysfunctional autonomic regulation during REM sleep as indexed by heart rate variability (HRV) is a pathophysiological factor in frequent nightmares (NMs). DESIGN Monitoring with polysomnography (PSG) and electrocardiography (ECG) for 3 consecutive nights: Night 1 (N1), adaptation night; N2, administration of partial REM sleep deprivation; N3, recovery night. Differences between NM and control (CTL) groups assessed for ECG measures drawn from wakefulness, REM sleep, and Stage 2 sleep on both N1 and N3. SETTING Hospital-based sleep laboratory. PARTICIPANTS Sixteen subjects with frequent NMs (> or = 1 NM/week; mean age = 26.1 +/- 8.7 years) but no other medical or psychiatric disorders and 11 healthy comparison subjects ( < 1 NM/month; mean age = 27.1+/- 5.6 years). RESULTS NM and CTL groups differed on 2 REM sleep measures only on N1; the NM group had longer REM latencies and REM/NREM cycle durations than did the CTL group. No differences were found on time domain and absolute frequency domain ECG measures for either N1 or N3. However, altered HRV for the NM group was suggested by significantly higher LFnu, lower HFnu, and higher LF/HF ratio than for the CTL group. CONCLUSIONS Results are consistent with a higher than normal sympathetic drive among NM subjects which is unmasked by high REM sleep propensity. Results also support a growing literature linking anxiety disorders of several types (panic disorder, posttraumatic stress disorder (PTSD), generalized anxiety disorder) to altered HR variability.
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Affiliation(s)
- Tore Nielsen
- Sleep Research Center, Hôpital du Sacré-Coeur de Montréal, Québec, Canada.
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Nielsen TA, Paquette T, Solomonova E, Lara-Carrasco J, Popova A, Levrier K. REM sleep characteristics of nightmare sufferers before and after REM sleep deprivation. Sleep Med 2009; 11:172-9. [PMID: 20005773 DOI: 10.1016/j.sleep.2008.12.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 12/09/2008] [Accepted: 12/12/2008] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology. BACKGROUND Heightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dream-like quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs. METHODS A preliminary study of 14 subjects with frequent NMs (> or = 1 NM/week; 27.6+/-9.9 years) and 11 healthy control subjects (<1 NM/month; 24.3+/-5.3 years) was undertaken. Subjects completed home sleep/dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3. RESULTS Several measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density, REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study. CONCLUSIONS Findings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity.
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Affiliation(s)
- Tore A Nielsen
- Dream and Nightmare Laboratory, Centre détude du sommeil, Hôpital du Sacré-Coeur de Montréal, 5400 boul. Gouin Ouest, Montréal, Que., Canada H4J1C5.
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Abstract
STUDY OBJECTIVES Evaluate the prevalence and phenomenology of dream-associated behaviors affecting pregnant and postpartum mothers. Episodes consist of anxious dreams and nightmares about the new infant that are accompanied by complex behaviors (motor activity, speaking, expressing emotion). DESIGN Three-group design (postpartum, pregnant, null gravida), self-report, and repeated measures. SETTING Pregnancy and postpartum groups: completion of questionnaires in hospital room within 48 hours of giving birth and home telephone interviews; null gravida group: completion of questionnaires and interview in person or by telephone. PARTICIPANTS Two hundred seventy-three women in 3 groups: postpartum: n = 202 (mean age = 29.7 +/- 4.94 years; 95 primiparas, 107 multiparas); pregnant: n = 50 (mean age = 31.1 +/- 5.44 years); null gravida: n = 21 (mean age = 28.5 +/- 6.34 years). INTERVENTIONS Subjects completed questionnaires about pregnancy and birth factors, personality, and sleep and participated in interviews concerning the prevalence of recent infant dreams and nightmares, associated behaviors, anxiety, depression, and other psychopathologic factors. MEASUREMENTS AND RESULTS Most women in all groups recalled dreams (88%-91%). Postpartum and pregnant women recalled infant dreams and nightmares with equal prevalence, but more postpartum women reported they contained anxiety (75%) and the infant in peril (73%) than did pregnant women (59%, P < 0.05 and 42%, P < 0.0001). More postpartum (63%) than pregnant (40%) women reported dream-associated behaviors (P < 0.01), but neither group differed from null gravida women (56%). This was due to different distributions over groups of the behavior subtypes. Motor activity was present in twice as many postpartum (57%) as pregnant (24%) or null gravida (25%) women (all P < 0.0001). Expressing emotion was more prevalent among null gravida (56%) than postpartum women (27%) (P < 0.05) but was not different from pregnant women (37%). Speaking was equally prevalent among the 3 groups (12%-19%). Behaviors were associated with nightmares, dream anxiety and, among postpartum women, post-awakening anxiety (41%), confusion (51%), and a need to check on the infant (60%). Primiparas and multiparas differed in dream and nightmare recall but not in prevalence of dream-associated behaviors. CONCLUSION The prevalent occurrence of pregnancy and postpartum infant dreams and associated behaviors may reflect the pervasive emotional influence of maternal concerns or changes instigated by severe sleep disruption, rapid eye movement sleep deprivation, and altered hormone levels.
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Affiliation(s)
- Tore Nielsen
- Dream & Nightmare Laboratory, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.
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Abstract
Relationships between Alpha (8-12 Hz) activity and cognitive processes during wakefulness raise the possibility of similar relationships between Alpha and cognitive activity during sleep. We hypothesized that Alpha power decreases during both Stage 2 and REM sleep would index the presence of sleep mentation in these stages. Absolute power for six classical EEG bands and three Alpha subbands was calculated for Stage 2 and REM sleep awakenings both with and without mentation recall. In both stages, recall was associated with lower Alpha power, especially with middle Alpha power (9.5-11.5 Hz). Unexpectedly, a similar effect for Delta power (0.5-4.0 Hz) was also observed. The Alpha effect may reflect cognitive elaboration active in the minutes preceding awakening; however, attention and memory processes cannot be excluded. The Delta effect is consistent with prior observations of regular linkages between Alpha and Delta power during sleep.
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Affiliation(s)
- Maria Josè Esposito
- Sleep Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada
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Paquette T, Clay JR, Ogbaghebriel A, Shrier A. Effects of divalent cations on the E-4031-sensitive repolarization current, I(Kr), in rabbit ventricular myocytes. Biophys J 1998; 74:1278-85. [PMID: 9512025 PMCID: PMC1299475 DOI: 10.1016/s0006-3495(98)77841-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The effects of divalent cations on the E-4031-sensitive repolarization current (I(Kr)) were studied in single ventricular myocytes isolated from rabbit hearts. One group of divalent cations (Cd2+, Ni2+, Co2+, and Mn2+) produced a rightward shift of the I(Kr) activation curve along the voltage axis, increased the maximum I(Kr) amplitude (i.e., relieved the apparent inward rectification of the channel), and accelerated I(Kr) tail current kinetics. Another group (Ca2+, Mg2+ and Sr2+) had relatively little effect on I(Kr). The only divalent cation that blocked I(Kr) was Zn2+ (0.1-1 mM). Under steady-state conditions, Ba2+ caused a substantial block of I(K1) as previously reported. However, block by Ba2+ was time dependent, which precluded a study of Ba2+ effects on I(Kr). We conclude that the various effects of the divalent cations can be attributed to interactions with distinct sites associated with the rectification and/or inactivation mechanism of the channel.
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Affiliation(s)
- T Paquette
- Department of Physiology, McGill University, Montréal, Québec, Canada
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Clay JR, Ogbaghebriel A, Paquette T, Sasyniuk BI, Shrier A. A quantitative description of the E-4031-sensitive repolarization current in rabbit ventricular myocytes. Biophys J 1995; 69:1830-7. [PMID: 8580326 PMCID: PMC1236416 DOI: 10.1016/s0006-3495(95)80053-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have measured the E-4031-sensitive repolarization current (IKr) in single ventricular myocytes isolated from rabbit hearts. The primary goal of this analysis was a description of the IKr kinetic and ion transfer properties. Surprisingly, the maximum time constant of this component was 0.8 s at 33-34 degrees C, which is significantly greater than the value of 0.18 s previously reported under similar conditions in the original measurements of IKr from guinea pig ventricular myocytes. The primary, novel feature of our analysis concerns the relationship of the bell-shaped curve that describes the voltage dependence of the kinetics and the sigmoidal curve that describes the activation of IKr. The midpoint of the latter occurred at approximately +10 mV on the voltage axis, as compared to -30 mV for the point on the voltage axis at which the maximum time constant occurred. Moreover, the voltage dependence of the kinetics was much broader than the steepness of the activation curve would predict. Taken together, these results comprise a gating current paradox that is not resolved by the incorporation of a fast inactivated state in the analysis. The fully activated current-voltage relation for IKr exhibited strong inward-going rectification, so much so that the current was essentially nil at +30 mV, even though the channel opens rapidly in this voltage range. This result is consistent with the lack of effect of E-4031 on the early part of the plateau phase of the action potential. Surprisingly, the reversal potential Of /Kr was ~15 mV positive to the potassium ion equilibrium potential,which indicates that this channel carries inward current during the latter part of the repolarization phase of the action potential.
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Affiliation(s)
- J R Clay
- Laboratory of Neurophysiology, National Institutes of Health, Bethesda, Maryland 20897, USA
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Wiederanders B, Broemme D, Kirschke H, Kalkkinen N, Rinne A, Paquette T, Toothman P. Primary structure of bovine cathepsin S. Comparison to cathepsins L, H, B and papain. FEBS Lett 1991; 286:189-92. [PMID: 1864368 DOI: 10.1016/0014-5793(91)80971-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The primary structure of bovine cathepsin S was determined by combining results of protein and peptide sequencing with the sequence deduced from nucleic acid sequencing. Using polymerase chain reaction (PCR) technology, cDNA clones commencing at amino acid 22 of the mature enzyme and continuing through the 3' untranslated region of bovine cathepsin S mRNA were isolated and sequenced. The open reading frame in these overlapping clones correctly predicts the determined amino acid sequence of 13 tryptic peptides derived from purified bovine spleen cathepsin S. The deduced amino acid sequence shows that mature bovine cathepsin S consists of 217 amino acids corresponding to a molecular weight of 23.7 kDa. Cathepsin S belongs to the papain superfamily of lysosomal cysteine proteinases and shares 41% identity with papain. Amino acid sequence identities of bovine cathepsin S to human cathepsins L, H, and B are 56%, 47% and 31% respectively.
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Affiliation(s)
- B Wiederanders
- Institute of Biochemistry, Faculty of Medicine, University of Halle, Germany
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Abstract
Both a high physiological concentration (13.1 nM) of epinephrine (E) and acute exercise (AEx) have previously been shown to increase 125I-insulin binding in skeletal muscle. To investigate the site and mechanism of the effect of epinephrine on binding and the possible link between epinephrine- and AEx-enhanced insulin binding, we measured insulin binding in three different preparations: 1) crude membranes derived from whole soleus muscle incubated in vitro with 13.1 nM E, 2) crude membranes with E present in the binding assay, and 3) purified plasma membranes with E present. Epinephrine enhanced binding in all three preparations by 169, 144, and 164%, respectively, at low concentrations of insulin but had little effect at high concentrations. Epinephrine, therefore appears to have its effect at the plasma membrane. Propranolol (10 microM), a beta-adrenergic antagonist, blocked E-enhanced insulin binding and when added to crude membranes made from soleus and extensor digitorum longus muscle of AEx rats reversed the increase in binding seen with exercise. This indicates that E-enhanced insulin binding is mediated by beta-adrenergic receptors and that AEx enhances insulin binding via beta-adrenergic receptors. Sodium orthovanadate (3 mM), a phosphotyrosyl-protein phosphatase inhibitor, also inhibited the increase in insulin binding due to E, implying that E may increase insulin binding by activating a phosphotyrosyl-protein phosphatase which decreases the phosphorylation of a plasma membrane protein, presumably the insulin receptor.
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Baskin DG, Brewitt B, Davidson DA, Corp E, Paquette T, Figlewicz DP, Lewellen TK, Graham MK, Woods SG, Dorsa DM. Quantitative autoradiographic evidence for insulin receptors in the choroid plexus of the rat brain. Diabetes 1986; 35:246-9. [PMID: 3510931 DOI: 10.2337/diab.35.2.246] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Techniques of in vitro receptor autoradiography were used to visualize binding of 125I-insulin on slices of frozen rat brain. Slide-mounted sections of frozen rat brain were incubated in 0.05 nM porcine 125I-monoiodoinsulin, alone or mixed with 1 microM unlabeled porcine insulin, ribonuclease, or glucagon, for 2 h at 22 degrees C. The labeled brain slices were apposed to LKB Ultrofilm to generate autoradiograms. The method permitted equal access of labeled insulin to both sides of the blood-brain barrier and localization of insulin binding sites in small anatomic regions. Quantitative estimates of specific iodoinsulin binding were made by computer digital image densitometry of the autoradiographic film images. High concentrations of specific binding sites for iodoinsulin were present in the choroid plexus of the lateral (26.9 +/- 2.0 X 10(-3) fmol/mm2), fourth (18.3 +/- 3.0 X 10(-3) fmol/mm2), and third (13.2 +/- 1.5 X 10(-3) fmol/mm2) ventricles (insulin binding is expressed per unit area of autoradiographic image). Binding to the third ventricular choroid plexus was similar to the concentrations observed for liver slices and the external plexiform layer of the olfactory bulb. Specific binding of iodoinsulin in the cingulate cortex and other surrounding regions was less than in choroid plexus. Ribonuclease or glucagon had no measurable effect on binding when mixed with labeled insulin. The results support the hypothesis that the choroid plexus has a high density of receptors for insulin, and suggests that the choroid plexus may be a target of CSF insulin action and/or a site of insulin transport into the CSF.
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Abstract
We measured insulin binding to crude membranes from rat skeletal muscle, with binding expressed relative to the sarcolemmal marker, cholesterol ester (CE). The amount of CE in the sarcolemma remained constant after streptozotocin-induced diabetes and acute exercise (swam for 90 min). Soleus (predominantly slow-twitch fibers) had higher insulin binding capacity than extensor digitorum longus (predominantly fast twitch). Both diabetes and acute exercise enhanced insulin binding. The shape of the enhanced insulin binding curve differed, however, between diabetes and acute exercise. Diabetes elicited a uniform increase in binding across the insulin concentrations measured (0.04-166 nM); acute exercise elicited the largest increase at the lower concentrations, suggesting different mechanisms cause the enhanced binding. Addition of 13.1 nM epinephrine to the perfusate in a rat hindlimb preparation increased insulin binding in a pattern similar to acute exercise. In contrast, muscular contraction stimulated by the sciatic nerve (1 Hz) or reduction of perfusate insulin from 100 to 40 pM, two additional correlates of acute exercise, had no effect. The increased insulin binding after acute exercise, therefore, appears to be mediated through elevated levels of catecholamines and not upregulation of the insulin receptor.
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Figlewicz DP, Dorsa DM, Stein LJ, Baskin DG, Paquette T, Greenwood MR, Woods SC, Porte D. Brain and liver insulin binding is decreased in Zucker rats carrying the 'fa' gene. Endocrinology 1985; 117:1537-43. [PMID: 3896761 DOI: 10.1210/endo-117-4-1537] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Insulin binding was measured in membrane particles prepared from the liver and several brain regions of 4-month-old female Zucker fa/fa (obese), Fa/fa (heterozygous), and Fa/Fa (lean) rats. High affinity insulin binding was decreased in the olfactory bulb of fatty (0.23 pmol bound/mg protein) and heterozygous (0.16 pmol/mg) rats compared with that in the lean controls (0.64 pmol/mg). Total binding was not changed in the cerebral cortex or hypothalamus. High affinity insulin binding was also decreased in the liver of both fatty (0.44 +/- 0.22 pmol/mg; P less than 0.01) and heterozygous (0.75 +/- 0.35 pmol/mg) animals compared with that in the lean rats (2.10 +/- 1.55 pmol/mg). This decreased binding is probably not due to down-regulation of receptors in the heterozygous rats, as they do not exhibit the hyperinsulinemia observed in the fatty rats. Rather, our findings suggest that there is a gene-related alteration in insulin binding in the Zucker rat, as low binding was observed in rats carrying either one (Fa/fa) or two (fa/fa) doses of the gene. We postulate that this central defect in insulin binding may contribute to inadequate perception of a central insulin feedback signal and to the hyperphagia observed in the obese rats.
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