1
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Shen HC, Bui KTA, Richard R, Toban N, Lévesque M, Meunier RS, Ross C, Makhzoum JP. Comparison of Interstitial Lung Disease Between Antineutrophil Cytoplasmic Antibodies Positive and Negative Patients: A Retrospective Cohort Study. ACR Open Rheumatol 2024. [PMID: 38733262 DOI: 10.1002/acr2.11679] [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] [Received: 12/05/2023] [Revised: 03/11/2024] [Accepted: 04/09/2024] [Indexed: 05/13/2024] Open
Abstract
OBJECTIVE Positive antineutrophil cytoplasmic antibodies (ANCAs) may occur in the setting of interstitial lung disease (ILD), with or without ANCA-associated vasculitis (AAV). We aim to compare the characteristics and clinical course of patients with ILD and positive ANCA (ANCA-ILD) to those with negative ANCA. METHODS We performed a single-center retrospective cohort study from 2018 to 2021. All patients with ILD and ANCA testing were included. Patient characteristics (symptoms, dyspnea scale, and systemic AAV), test results (pulmonary high-resolution computed tomography and pulmonary function tests), and adverse events were collected from electronic medical records. Descriptive statistics and the Fisher exact test were used to compare the outcomes of patients with ANCA-ILD to those with ILD and negative ANCA. RESULTS A total of 265 patients with ILD were included. The mean follow-up duration was 69.3 months, 26 patients (9.8%) were ANCA positive, and 69.2% of those with ANCA-ILD had another autoantibody. AAV occurred in 17 patients (65.4%) with ANCA-ILD. In 29.4% of patients, AAV developed following ILD diagnosis. Usual interstitial pneumonia was the most common radiologic pattern in patients with ANCA-ILD. There was no association between ANCA status and the evolution of dyspnea, diffusing capacity of the lungs for carbon monoxide, and lung imaging. Forced vital capacity improved over time in 42% of patients with ANCA-ILD and in 17% of patients with negative ANCA (P = 0.006). Hospitalization occurred in 46.2% of patients with ANCA-ILD and in 21.8% of patients with negative ANCA (P = 0.006). Both groups had similar mortality rates. CONCLUSION Routine ANCA testing should be considered in patients with ILD. Patients with ANCA-ILD are at risk for AAV. More research is required to better understand and manage patients with ANCA-ILD.
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Affiliation(s)
- Hao Cheng Shen
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
| | | | - Rachel Richard
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
| | - Nader Toban
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
| | - Marianne Lévesque
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
| | | | - Carolyn Ross
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
| | - Jean-Paul Makhzoum
- Hôpital du Sacré-Cœur de Montréal and Université de Montréal, Montreal, Canada
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2
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Villeneuve K, Beaulieu-Bonneau S, Hudon C, Souesme G, Lévesque M, Predovan D, Sirois MJ, de Guise É, Lamontagne MÈ, Poulin V, Le Sage N, Émond M, Ouellet MC. Subjective and objective burden and psychological distress in care partners of older adults with traumatic brain injury. Rehabil Psychol 2023:2023-85628-001. [PMID: 37384485 DOI: 10.1037/rep0000500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
PURPOSE/OBJECTIVE In care partners of older persons (65 years and older) having sustained traumatic brain injury (TBI), the objectives were (a) to describe subjective burden (emotional, social, financial, and physical burden), objective burden (new roles and responsibilities), and psychological distress at 4 months postinjury, and (b) to explore the predictors of subjective burden and psychological distress. RESEARCH METHOD/DESIGN This is an observational study of care partners of older adults with TBI (n = 46; Mage = 65.2 years, SD = 11.2, 87% female). Participants completed the Zarit Burden Interview, the Hospital Anxiety and Depression Scale, the Brain Injury Complaint Questionnaire (measuring difficulties of the injured older adult perceived by the care partner), and the modified Medical Outcomes Study Social Support Survey. RESULTS A majority of care partners (88%) reported at least one form of objective burden (e.g., increased/decreased time spent in certain activities post-TBI), 29% perceived at least mild subjective burden, and 27% reported either significant anxiety or depressive symptoms. Linear regressions indicated that a higher number of difficulties reported regarding the injured person and poorer perceived social support predicted higher subjective burden and psychological distress. A younger age of the care partner also predicted a higher subjective burden. CONCLUSIONS/IMPLICATIONS This study provides a better understanding of the potential impacts of TBI in older age for care partners. Future research should examine how to support adequately care partners in their psychological adaptation after TBI in an elderly person. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Affiliation(s)
| | | | | | - Guillaume Souesme
- Centre Interdisciplinaire de Recherche en Readaptation et Integration Sociale (CIRRIS)
| | | | - David Predovan
- Centre Interdisciplinaire de Recherche en Readaptation et Integration Sociale (CIRRIS)
| | | | | | - Marie-Ève Lamontagne
- Centre Interdisciplinaire de Recherche en Readaptation et Integration Sociale (CIRRIS)
| | - Valérie Poulin
- Centre Interdisciplinaire de Recherche en Readaptation et Integration Sociale (CIRRIS)
| | | | - Marcel Émond
- Centre de recherche du CHU de Quebec, Universite Laval
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3
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Klesse S, Wohlgemuth T, Meusburger K, Vitasse Y, von Arx G, Lévesque M, Neycken A, Braun S, Dubach V, Gessler A, Ginzler C, Gossner MM, Hagedorn F, Queloz V, Samblás Vives E, Rigling A, Frei ER. Long-term soil water limitation and previous tree vigor drive local variability of drought-induced crown dieback in Fagus sylvatica. Sci Total Environ 2022; 851:157926. [PMID: 35985592 DOI: 10.1016/j.scitotenv.2022.157926] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Ongoing climate warming is increasing evapotranspiration, a process that reduces plant-available water and aggravates the impact of extreme droughts during the growing season. Such an exceptional hot drought occurred in Central Europe in 2018 and caused widespread defoliation in mid-summer in European beech (Fagus sylvatica L.) forests. Here, we recorded crown damage in 2021 in nine mature even-aged beech-dominated stands in northwestern Switzerland along a crown damage severity gradient (low, medium, high) and analyzed tree-ring widths of 21 mature trees per stand. We aimed at identifying predisposing factors responsible for differences in crown damage across and within stands such as tree growth characteristics (average growth rates and year-to-year variability) and site-level variables (mean canopy height, soil properties). We found that stand-level crown damage severity was strongly related to soil water availability, inferred from tree canopy height and plant available soil water storage capacity (AWC). Trees were shorter in drier stands, had higher year-to-year variability in radial growth, and showed higher growth sensitivity to moisture conditions of previous late summer than trees growing on soils with sufficient AWC, indicating that radial growth in these forests is principally limited by soil water availability. Within-stand variation of post-drought crown damage corresponded to growth rate and tree size (diameter at breast height, DBH), i.e., smaller and slower-growing trees that face more competition, were associated with increased crown damage after the 2018 drought. These findings point to tree vigor before the extreme 2018 drought (long-term relative growth rate) as an important driver of damage severity within and across stands. Our results suggest that European beech is less likely to be able to cope with future climate change-induced extreme droughts on shallow soils with limited water retention capacity.
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Affiliation(s)
- S Klesse
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland.
| | - T Wohlgemuth
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - K Meusburger
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Y Vitasse
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - G von Arx
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - M Lévesque
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
| | - A Neycken
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
| | - S Braun
- Institute for Applied Plant Biology AG, Witterswil, Switzerland
| | - V Dubach
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - A Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland; Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
| | - C Ginzler
- Land Change Science, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - M M Gossner
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland; Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - F Hagedorn
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - V Queloz
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - E Samblás Vives
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland; Autonomous University of Barcelona (UAB), 08193 Cerdanyola del Valles, Spain
| | - A Rigling
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland; Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
| | - E R Frei
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland; Alpine Environment and Natural Hazards, WSL Institute for Snow and Avalanche Research SLF, 7260 Davos Dorf, Switzerland; Climate Change and Extremes in Alpine Regions Research Centre CERC, 7260 Davos Dorf, Switzerland
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4
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Gagnon C, Olmand M, Dupuy EG, Besnier F, Vincent T, Grégoire CA, Lévesque M, Payer M, Bérubé B, Breton J, Lecchino C, Bouabdallaoui N, Iglesies-Grau J, Gayda M, Vitali P, Nigam A, Juneau M, Hudon C, Bherer L. Videoconference version of the Montreal Cognitive Assessment: normative data for Quebec-French people aged 50 years and older. Aging Clin Exp Res 2022; 34:1627-1633. [PMID: 35178685 PMCID: PMC8853900 DOI: 10.1007/s40520-022-02092-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/02/2022] [Indexed: 11/29/2022]
Abstract
Background The COVID-19 pandemic forced health professionals to rapidly develop and implement telepractice and remote assessments. Recent reviews appear to confirm the validity of a wide range of neuropsychological tests for teleneuropsychology and among these, the Montreal Cognitive Assessment (MoCA), a cognitive screening test widely used in clinical settings. The normative data specific to the context of videoconference administration is essential, particularly that consider sociodemographic characteristics. Aims This study had for objective to develop French-Quebec normative data for videoconference-administration of the MoCA that consider sociodemographic characteristics. Methods A total of 230 community-dwelling adults aged 50 years and older taking part in clinical trials completed the MoCA by videoconference. Regression analyses were run with sex, education, and age as predictors of the total MoCA scores, based on previously published norms. As an exploratory analysis, a second regression analysis was also run with cardiovascular disease as a predictor. Results Regression analyses revealed that older age and lower education were associated with poorer total MoCA scores, for medium effect size (p < 0.001, R2 = 0.17). Neither sex nor cardiovascular disease, were significant predictors in our analyses. For clinicians, a regression equation was proposed to calculate Z scores. Discussion This study provides normative data for the MoCA administered via videoconference in Quebec-French individuals aged 50 years and over. Conclusions The present normative data will not only allow clinicians to continue to perform assessments remotely in this pandemic period but will also allow them to perform cognitive assessments to patients located in remote areas. Supplementary Information The online version contains supplementary material available at 10.1007/s40520-022-02092-1.
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Affiliation(s)
- Christine Gagnon
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada.
| | - Miloudza Olmand
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Psychology, Université de Montréal, Montréal, Canada
| | - Emma Gabrielle Dupuy
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Florent Besnier
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Thomas Vincent
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
| | - Catherine-Alexandra Grégoire
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
| | - Marianne Lévesque
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Psychology, Université de Montréal, Montréal, Canada
| | - Marie Payer
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Psychology, Université du Québec à Montréal, Montréal, Canada
- Research Center, Institut Universitaire en Santé Mentale de Montréal, Montréal, QC, H1N 3M5, Canada
| | - Béatrice Bérubé
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Psychology, Université du Québec à Montréal, Montréal, Canada
| | - Juliana Breton
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
| | - Catia Lecchino
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Psychology, Université de Montréal, Montréal, Canada
| | - Nadia Bouabdallaoui
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Josep Iglesies-Grau
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Mathieu Gayda
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Paolo Vitali
- Research Centre for Studies on Aging, McGill University, Montréal, Canada
- Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal, Canada
| | - Anil Nigam
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Martin Juneau
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Carol Hudon
- École de Psychologie, Université Laval, Québec, Canada
- Centre de Recherche CERVO, Québec, Canada
| | - Louis Bherer
- Centre ÉPIC and Research Center, Montreal Heart Institute, 5055 rue St Zotique Est, Montréal, QC, H1T 1N6, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, Canada
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5
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Strikwerda-Brown C, Williams K, Lévesque M, Brambati S, Sheldon S. What are your thoughts? Exploring age-related changes in episodic and semantic autobiographical content on an open-ended retrieval task. Memory 2021; 29:1375-1383. [PMID: 34637681 DOI: 10.1080/09658211.2021.1987476] [Citation(s) in RCA: 4] [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] [Indexed: 10/20/2022]
Abstract
Older adults display impairments in accessing episodic, but not semantic details, when specifically requested to construct autobiographical events. How aging affects access to autobiographical information under conditions of low retrieval constraint remains unclear. We examined the production of episodic and "non-episodic" details in young (n = 25) and older (n = 24) adults on a novel autobiographical narrative task free from constraints on the type of information to be retrieved (Thoughts task), compared with the standard autobiographical memory and picture description tasks. Older adults generated fewer episodic and more non-episodic details on the memory task than young adults, however there was no age difference in detail profiles on the Thoughts task. Under these conditions of low retrieval constraint, narratives of young and older adults consisted of mostly personal and general semantic content. Young adults also provided less episodic and more semantic details on the Thoughts than the memory task, while older adults provided similar amounts of details across tasks. These results reveal that both young and older adults retrieve semantic autobiographical content under minimally constrained retrieval conditions. Moreover, aging may impact upon the ability to shift the detail types (episodic, semantic) provided in response to changing demands of different autobiographical narrative tasks.
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Affiliation(s)
- Cherie Strikwerda-Brown
- Brain and Mind Centre, The University of Sydney, Sydney, Australia.,School of Psychology, the University of Sydney, Sydney, Australia
| | - Kayla Williams
- Department of Psychology, McGill University, Montreal, Canada
| | | | - Simona Brambati
- Department of Psychology, University de Montreal, Montreal, Canada
| | - Signy Sheldon
- Department of Psychology, McGill University, Montreal, Canada
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6
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Quessy F, Bittar T, Blanchette LJ, Lévesque M, Labonté B. Stress-induced alterations of mesocortical and mesolimbic dopaminergic pathways. Sci Rep 2021; 11:11000. [PMID: 34040100 PMCID: PMC8154906 DOI: 10.1038/s41598-021-90521-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/04/2021] [Indexed: 02/07/2023] Open
Abstract
Our ability to develop the cognitive strategies required to deal with daily-life stress is regulated by region-specific neuronal networks. Experimental evidence suggests that prolonged stress in mice induces depressive-like behaviors via morphological, functional and molecular changes affecting the mesolimbic and mesocortical dopaminergic pathways. Yet, the molecular interactions underlying these changes are still poorly understood, and whether they affect males and females similarly is unknown. Here, we used chronic social defeat stress (CSDS) to induce depressive-like behaviors in male and female mice. Density of the mesolimbic and mesocortical projections was assessed via immuno-histochemistry combined with Sholl analysis along with the staining of activity-dependent markers pERK and c-fos in the ventral tegmental area (VTA), nucleus accumbens (NAc) and medial prefrontal cortex (mPFC). Our results show that social stress decreases the density of TH+ dopaminergic axonal projections in the deep layers of the mPFC in susceptible but not resilient male and female mice. Consistently, our analyses suggest that pERK expression is decreased in the mPFC but increased in the NAc following CSDS in males and females, with no change in c-fos expression in both sexes. Overall, our findings indicate that social defeat stress impacts the mesolimbic and mesocortical pathways by altering the molecular interactions regulating somatic and axonal plasticity in males and females.
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Affiliation(s)
- F Quessy
- CERVO Brain Research Centre, Quebec, QC, Canada.,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Quebec, QC, Canada
| | - T Bittar
- CERVO Brain Research Centre, Quebec, QC, Canada.,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Quebec, QC, Canada
| | - L J Blanchette
- CERVO Brain Research Centre, Quebec, QC, Canada.,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Quebec, QC, Canada
| | - M Lévesque
- CERVO Brain Research Centre, Quebec, QC, Canada. .,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Quebec, QC, Canada.
| | - B Labonté
- CERVO Brain Research Centre, Quebec, QC, Canada. .,Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, Quebec, QC, Canada.
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7
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Lévesque M, Ouellet M, Meilleur‐Durand S, Bouchard RW, Verret L, Fortin M, Nadeau Y, Molin P, Caron S, Hudon C, Masellis M, Cunnane S, Villeneuve S, Gauthier S, Callahan BL, Jarrett P, Hsiung GR, Laforce R. Cognitive differences between healthy monolingual and bilingual anglophones on the English version of the Dépistage Cognitif de Québec: A new screening tool for atypical dementia. Alzheimers Dement 2020. [DOI: 10.1002/alz.047103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marianne Lévesque
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
- École de Psychologie, Faculté des Sciences Sociales Université Laval Quebec QC Canada
- Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS) Quebec QC Canada
| | - Marie‐Christine Ouellet
- École de Psychologie, Faculté des Sciences Sociales Université Laval Quebec QC Canada
- Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS) Quebec QC Canada
| | - Synthia Meilleur‐Durand
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
- Faculté de Médecine Université Laval Quebec QC Canada
| | - Rémi W. Bouchard
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | - Louis Verret
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | - Marie‐Pierre Fortin
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | - Yannick Nadeau
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | - Pierre Molin
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | - Stéphanie Caron
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
| | | | | | | | | | - Serge Gauthier
- McGill University Research Centre for Studies in Aging Montreal QC Canada
| | - Brandy L. Callahan
- University of Calgary and University of Calgary & Hotchkiss Brain Institute Calgary AB Canada
| | | | | | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire CHU de Québec‐Université Laval Quebec QC Canada
- Faculté de Médecine Université Laval Quebec QC Canada
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8
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St-Onge F, Coulombe V, Meilleur-Durand S, Lévesque M, Sellami L, Paquette-Raynard E, Laforce R. P2-362: IMAGING CHARACTERISTICS OF PRE-SYMPTOMATIC FAMILIAL FRONTOTEMPORAL DEMENTIA: A SYSTEMATIC REVIEW (PROTOCOL). Alzheimers Dement 2019. [DOI: 10.1016/j.jalz.2019.06.2769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Frederic St-Onge
- Faculté de Médecine, Département de Psychiatrie et de Neurosciences; Université Laval; Quebec QC Canada
- Centre de Recherche du CHU de Québec-Université Laval; Quebec QC Canada
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques; CHU de Québec-Université Laval; Quebec QC Canada
| | - Valerie Coulombe
- Centre de Recherche CERVO Research Center; Quebec QC Canada
- Faculté de Médecine, Département de Réadaptation; Quebec QC Canada
- Centre for Interdisciplinaire Research in Rehabilitation and Social Integration; Quebec QC Canada
| | - Synthia Meilleur-Durand
- Université Laval; Faculté de Médecine; Quebec QC Canada
- Clinique Interdisciplinaire de Memoire du CHU de Quebec; Quebec QC Canada
| | - Marianne Lévesque
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques; CHU de Québec-Université Laval; Quebec QC Canada
- Centre de Recherche du CHU de Québec-Université Laval; Quebec QC Canada
- École de Psychologie, Faculté des Sciences Sociales; Université Laval; Quebec QC Canada
| | - Leila Sellami
- Université Laval; Faculté de Médecine; Quebec QC Canada
- Clinique de Mémoire Département des Sciences Neurologiques; CHU de Québec; Quebec QC Canada
| | | | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques; CHU de Québec-Université Laval; Quebec QC Canada
- Faculté de Médecine; Université Laval; Quebec QC Canada
- Centre de Recherche du CHU de Québec-Université Laval; Québec QC Canada
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9
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Levasseur M, Lévesque M, Beaudry M, Lariviere N, Filiatrault J, Parisien M, Couturier Y, Champoux N. IMPACTS OF THE FRENCH LIFESTYLE REDESIGN®, A PREVENTIVE OCCUPATIONAL THERAPY INTERVENTION. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.3270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M. Levasseur
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - M. Lévesque
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - M. Beaudry
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - N. Lariviere
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
| | | | - M. Parisien
- Centre de réadaptation en déficience physique-Institut universitaire, Monréal, Quebec, Canada
| | - Y. Couturier
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - N. Champoux
- Université de Montréal, Montréal, Quebec, Canada,
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10
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Cisbani G, Drouin-Ouellet J, Gibrat C, Saint-Pierre M, Lagacé M, Badrinarayanan S, Lavallée-Bourget M, Charest J, Chabrat A, Boivin L, Lebel M, Bousquet M, Lévesque M, Cicchetti F. Cystamine/cysteamine rescues the dopaminergic system and shows neurorestorative properties in an animal model of Parkinson's disease. Neurobiol Dis 2015; 82:430-444. [DOI: 10.1016/j.nbd.2015.07.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/08/2015] [Accepted: 07/22/2015] [Indexed: 12/22/2022] Open
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11
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Hamidi S, Lévesque M, Avoli M. Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices. Neuroscience 2014; 281:258-68. [PMID: 25290016 DOI: 10.1016/j.neuroscience.2014.09.065] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [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: 07/09/2014] [Revised: 09/15/2014] [Accepted: 09/16/2014] [Indexed: 02/04/2023]
Abstract
We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.
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Affiliation(s)
- S Hamidi
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 University Street, Montréal, QC H3A 2B4, Canada
| | - M Lévesque
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 University Street, Montréal, QC H3A 2B4, Canada
| | - M Avoli
- Montreal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 University Street, Montréal, QC H3A 2B4, Canada.
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12
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Herrington R, Lévesque M, Avoli M. Neurosteroids modulate epileptiform activity and associated high-frequency oscillations in the piriform cortex. Neuroscience 2013; 256:467-77. [PMID: 24157930 DOI: 10.1016/j.neuroscience.2013.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [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: 07/22/2013] [Revised: 10/09/2013] [Accepted: 10/12/2013] [Indexed: 01/13/2023]
Abstract
Allotetrahydrodeoxycorticosterone (THDOC) belongs to a class of pregnane neurosteroidal compounds that enhance brain inhibition by interacting directly with GABAA signaling, mainly through an increase in tonic inhibitory current. Here, we addressed the role of THDOC in the modulation of interictal- and ictal-like activity and associated high-frequency oscillations (HFOs, 80-500 Hz; ripples: 80-200 Hz, fast ripples: 250-500 Hz) recorded in vitro in the rat piriform cortex, a highly excitable brain structure that is implicated in seizure generation and maintenance. We found that THDOC: (i) increased the duration of interictal discharges in the anterior piriform cortex while decreasing ictal discharge duration in both anterior and posterior piriform cortices; (ii) reduced the occurrence of HFOs associated to both interictal and ictal discharges; and (iii) prolonged the duration of 4-aminopyridine-induced, glutamatergic independent synchronous field potentials that are known to mainly result from the activation of GABAA receptors. Our results indicate that THDOC can modulate epileptiform synchronization in the piriform cortex presumably by potentiating GABAA receptor-mediated signaling. This evidence supports the view that neurosteroids regulate neuronal excitability and thus control the occurrence of seizures.
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Affiliation(s)
- R Herrington
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montréal, Qc, Canada
| | - M Lévesque
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montréal, Qc, Canada
| | - M Avoli
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montréal, Qc, Canada.
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13
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14
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Lévesque M, Lema P, Langlois J, Courtemanche R, Carmant L. 4. Local field potential synchrony in the amygdalo–hippocampal network during kainate-induced seizures. Clin Neurophysiol 2008. [DOI: 10.1016/j.clinph.2008.04.284] [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: 10/21/2022]
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15
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Paquet F, Soucy JP, Stip E, Lévesque M, Elie A, Bédard MA. Comparison between olanzapine and haloperidol on procedural learning and the relationship with striatal D2 receptor occupancy in schizophrenia. J Neuropsychiatry Clin Neurosci 2004; 16:47-56. [PMID: 14990759 DOI: 10.1176/jnp.16.1.47] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The striatum is known to play a primary role in procedural learning. In this study, the authors simultaneously assessed the effects of two antipsychotic drugs on procedural learning and on striatal dopamine (D2) receptor occupancy. Twenty-seven patients receiving either olanzapine or haloperidol as antipsychotic medication were assessed with the Computed Visual Tracking Task (CVTT) and Single Photon Emission Computed Tomography (SPECT) following the administration of Iodine 123-IBZM (123I-IBZM), a radioligand with a high affinity and specificity for the D2 receptors. The results showed poorer procedural learning in the haloperidol-treated patients than in normal control subjects, while no difference could be found between olanzapine-treated patients and normal control subjects. In the haloperidol but not the olanzapine group, significant correlations were found between procedural learning deficits and striatal D2 receptor occupancy. However, there was no significant difference in D2 receptor occupancy between olanzapine- and haloperidol-treated patients, and this may be related to the high doses of olanzapine and low doses of haloperidol administered. The authors concluded that: 1) striatal D2 receptor blockade may alter procedural learning in humans; and 2) olanzapine may have a protective effect on procedural learning, even at doses that produce striatal D2 receptor occupancy as high as that found with haloperidol. This protective effect of olanzapine may be related to its atypical pharmacological properties.
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Affiliation(s)
- F Paquet
- Movement Disorder Unit, CHUM Hôtel-Dieu, UQAM, Canada
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16
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Caron J, Lévesque M. [Suicide in Abitibi-Temiscamingue region: epidemiological data for the period of 1992-96]. Can J Commun Ment Health 2002; 19:175-200. [PMID: 12152175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
A permanent register of suicide cases has been established and has made it possible to produce a quantitative description of the suicide phenomenon in Abitibi-Témiscamingue for the period 1992-1996. This study reviews 211 suicide cases reported by the Chief Coroner Office of Quebec. A content analysis grid was applied to the coroners' files and has facilitated the study of 87 variables potentially related to suicide. The results show the evolution of suicide rates in this region in relation to those in other parts of Quebec, and the differences among various parts of the region. Several variables are shown to be significantly related to suicide (sex, age, method used, suicide site, etc.). A review of recent literature on suicide throughout the world indicates that patterns of suicide in Abitibi-Témiscamingue follow present trends in North America and Europe, but with aspects particular to the region.
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Affiliation(s)
- J Caron
- Université du Québec en Abitibi-Témiscamingue Centre de recherche de l'Hôpital Douglas
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17
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Parent M, Lévesque M, Parent A. Two types of projection neurons in the internal pallidum of primates: single-axon tracing and three-dimensional reconstruction. J Comp Neurol 2001; 439:162-75. [PMID: 11596046 DOI: 10.1002/cne.1340] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [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: 11/09/2022]
Abstract
The axonal projections of the internal pallidum (GPi) in cynomolgus monkeys (Macaca fascicularis) were studied by labeling small pools of neurons with biotinylated dextran amine. Fifty-two axons were reconstructed entirely from serial sections with a camera lucida. Two types of projection neurons were identified in the GPi on the basis of their target sites. The abundant and centrally located type I neurons gave rise to a long axonal branch that descended directly to the pedunculopontine tegmental nucleus, where it arborized discretely. Other branches ascended to the thalamus and broke into 10-15 thinner collaterals that ran through most of the ventral anterior nucleus, where they terminated as typical plexuses. About half of these axons gave rise to collaterals that arborized in both components of the centre médian/parafascicular thalamic complex. The less numerous and peripherally located type II neurons had an axon that climbed the rostral thalamic pole, coursed along the stria medullaris, and arborized profusely within the lateral habenular nucleus, which stood out as the most densely innervated pallidal target. Some type II axons provided collaterals to the anterior thalamic nuclei. A small proportion of axons of both types had branches that crossed the midline and terminated in contralateral GPi target structures. Three-dimensional reconstruction showed that type I axons arborized principally along the sagittal plane. These data reveal that GPi neurons of type I act through a widely distributed axonal network upon thalamic and brainstem premotor neurons, whereas type II neurons act in a much more focused manner upon lateral habenular neurons.
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Affiliation(s)
- M Parent
- Centre de recherche Université Laval Robert-Giffard, 2601, Chemin de la Canardière, Beauport, Québec, Canada, G1J 2G3
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Abstract
The current model of basal ganglia organization has been developed progressively over the last two decades in the light of key observations made at both experimental and clinical levels. This model has been highly successful in that it has stimulated a large amount of research in the field. However, several experimental and clinical findings that are at odds with the model have accumulated during the last decade. This paper reviews some of our own single-axon tracing studies in primates, which call for a re-evaluation of the current basal ganglia model.
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Affiliation(s)
- A Parent
- Laboratoire de Neurobiologie, Centre de recherche Université Laval Robert-Giffard, 2601, de la Canardière, Que., G1J 2G3, Beauport, Canada
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Abstract
Recent neuroanatomical data obtained with single-axon or single-cell labeling procedures in both rodents and primates have revealed the presence of various types of projection neurons with profusely collateralized axons within each of the major components of the basal ganglia. Such findings call for a reappraisal of current concepts of the anatomical and functional organization of the basal ganglia,which play such a crucial role in the control of motor behavior. The basal ganglia now stand as a widely distributed neuronal network, whose elements are endowed with a highly patterned set of axon collaterals. The elucidation of this finely tuned network is needed to understand the complex spatiotemporal sequence of neural events that ensures the flow of cortical information through the basal ganglia.
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Affiliation(s)
- A Parent
- Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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20
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Sato F, Lavallée P, Lévesque M, Parent A. Single-axon tracing study of neurons of the external segment of the globus pallidus in primate. J Comp Neurol 2000; 417:17-31. [PMID: 10660885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Axonal projections arising from the external segment of the globus pallidus (GPe) in cynomolgus monkeys (Macaca fascicularis) were mapped after labeling small pools (5-15 cells) of neurons with biotinylated dextran amine. Seventy-six single axons were reconstructed from serial sagittal sections with a camera lucida. The majority of labeled GPe cells displayed long, aspiny, and poorly branched dendrites that arborized mostly along the sagittal plane, whereas others showed dendrites radiating in all directions. Numerous GPe axons emitted short, intranuclear collaterals that arborized close to their parent cell body. Based on their axonal targets, four distinct types of GPe projection neurons have been identified: 1) neurons that project to the internal segment of the globus pallidus (GPi), the subthalamic nucleus (STN), and the substantia nigra, pars reticulata (SNr; 13.2%); 2) neurons that target the GPi and the STN (18.4%); 3) neurons that project to the STN and the SNr (52.6%); and 4) neurons that target the striatum (15.8%). Labeled GPe axons displayed large varicosities that often were closely apposed to the somata and proximal dendrites of STN, GPi, and SNr neurons. At striatal levels, however, GPe axons displayed small axonal varicosities that did not form perineuronal nets. These results suggest that the GPe is an important integrative locus in primate basal ganglia. This nucleus harbors several subtypes of projection neurons that are endowed with a highly patterned set of collaterals. This organization allows single GPe neurons to exert a multifarious effect not only on the STN, which is the claimed GPe target, but also on the two major output structures of the basal ganglia, the SNr and the GPi.
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Affiliation(s)
- F Sato
- Laboratoire de Neurobiologie, Centre de Recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Abstract
Neurons of the substantia nigra pars compacta (SNc) were iontophoretically injected with biotin dextran and their anterogradely labeled axons individually reconstructed from serial sagittal sections. Most nigrostriatal axons travelled directly to the striatum, where they branched abundantly. Other axons arborized profusely in various extrastriatal structures, including the globus pallidus, the entopeduncular and subthalamic nuclei, and branched only sparsely in the striatum. This heterogeneous organization of the nigrostriatal projection allows single SNc neurons to influence differently striatal neurons and to act directly upon extrastriatal components of the basal ganglia via a highly patterned set of collaterals.
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Affiliation(s)
- J Gauthier
- Laboratoire de Neurobiologie, Centre de recherche Université Laval Robert-Giffard, 2601, Chemin de la Canardière, Local F-6500, Beauport, Quebec, Canada
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Parent M, Lévesque M, Parent A. The pallidofugal projection system in primates: evidence for neurons branching ipsilaterally and contralaterally to the thalamus and brainstem. J Chem Neuroanat 1999; 16:153-65. [PMID: 10422736 DOI: 10.1016/s0891-0618(99)00008-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [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: 12/01/2022]
Abstract
This paper summarizes the results of some of our previous neuroanatomical studies on the pallidofugal projections in squirrel monkeys and also reports more recent data obtained with double retrograde and single axon tracing methods. Injections of anterograde tracers in the internal pallidum label axons that reach the ventral tier, centromedian and lateral habenular thalamic nuclei, as well as the pedunculopontine tegmental nucleus. The pallidofugal projections are composed of axons that branch to the ventral tier and pedunculopontine nuclei, and to ventral tier and centromedian nuclei. Double retrograde labeling with fluorescent tracers and single axon tracing confirm this high degree of collateralization. Furthermore, some pallidal labeled axons cross the midline and arborize contralaterally in the major pallidal targets. Double retrograde fluorescent labeling experiments support these findings. Pallidal axons that branch ipsilaterally as well as contralaterally to the thalamus and brainstem could play a crucial role in the functional organization of primate basal ganglia.
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Affiliation(s)
- M Parent
- Laboratoire de Neurobiologie, Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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23
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Abstract
A tyrosine-hydroxylase immunohistochemical analysis of the brains of normal human individuals has revealed nigrostriatal axons providing collaterals that arborize in the pallidum and subthalamic nucleus. These thin and varicose collaterals emerge from thick and smooth axons that course backward along the main output pathways of the basal ganglia, including the ansa lenticularis, the lenticular fasciculus and Wilson's pencils. Many of these fibers run within pallidal medullary laminae before reaching the putamen, whereas others climb along the reticular thalamic nucleus to reach the caudate nucleus. This extrastriatal innervation, which allows nigral dopaminergic neurons to directly affect the pallidum and subthalamic nucleus, may play a crucial role in the functional organization of human basal ganglia, in both health and disease.
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Affiliation(s)
- M Cossette
- Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Abstract
This study aimed at elucidating the branching pattern of striatal and thalamic projections arising from prelimbic (Cg3) cortex in the rat. Small pools (5-15 cells) of neurons were microiontophoretically injected with biotin-dextran or biocytin and their labeled axons were individually reconstructed from serial horizontal sections immunostained for calbindin-D28k to delineate striatal patch/matrix compartments. Reconstruction of > 40 axons shows that all Cg3 corticofugal fibers, including corticothalamic axons from layer VI, course through the patch network in the rostromedial sector of the striatum. Corticostriatal projections arise from two types of layer V cells: (i) long-range corticofugal neurons, whose main axons reach the brainstem and/or spinal cord, and (ii) neurons arborizing into both striatum and claustrum, either ipsi-, contra- or bilaterally. The axons of these two types of neurons arborize profusely in striatal patches and only sparsely in the matrix. Layer VI neurons do not arborize in the striatum but target principally the thalamus. The same corticothalamic axon can innervate the anterior, rostral intralaminar and mediodorsal thalamic nuclei. These findings support the concept that no corticofugal fiber system exists that is solely devoted to the striatum. They also shed new light on how neural information from prelimbic cortex is conveyed to various subcortical limbic structures in the rat.
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Affiliation(s)
- M Lévesque
- Laboratoire de neurobiologie, Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Lévesque M, Gagnon S, Parent A. Axonal arborizations of corticostriatal and corticothalamic fibers arising from the second somatosensory area in the rat. Cereb Cortex 1996; 6:759-70. [PMID: 8922332 DOI: 10.1093/cercor/6.6.759] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [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: 02/03/2023] Open
Abstract
Corticostriatal and corticothalamic projections arising from the second somatosensory area in the rat were studied after labeling small pools of neurons in laminae V and VI with biocytin. Tracing the axon of single neurons revealed the following principles of organization: (i) all corticostriatal and corticothalamic projections arising from layer V cells are collaterals of long-range corticofugal axons that also project below the thalamic level; (ii) all layer V cells that project to the thalamus also project to the striatum; (iii) all layer VI corticothalamic cells project exclusively to the thalamus; (iv) cells of the upper part of lamina VI send collaterals to the thalamic reticular nucleus and arborize in the ventrobasal complex forming rod-like terminal fields; and (v) cells of the lower part of lamina VI also send collaterals to the thalamic reticular nucleus, give off few branches in the ventrobasal complex and terminate principally in the caudal part of the posterior thalamic group. On the basis of these findings, and in the light of previous anatomical studies, it is proposed that the above mentioned organizing principles represent general rules that also apply to corticostriatal and corticothalamic pathways arising from other areas of the neocortex.
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Affiliation(s)
- M Lévesque
- Centre de Recherche en Neurobiologie, Hôpital de l'Enfant-Jésus, Québec City, Canada
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Lévesque M. [Request for inquiry into the competence of a nurse]. Nurs Que 1992; 12:13-4. [PMID: 1436821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Sergent J, Zuck E, Lévesque M, MacDonald B. Positron emission tomography study of letter and object processing: empirical findings and methodological considerations. Cereb Cortex 1992; 2:68-80. [PMID: 1633409 DOI: 10.1093/cercor/2.1.68] [Citation(s) in RCA: 156] [Impact Index Per Article: 4.9] [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: 12/28/2022] Open
Abstract
The study of functional-anatomical correlations of higher-order cognitive processing has benefited from recent advances in brain imaging techniques such as positron emission tomography (PET) measurements of regional cerebral blood flow (CBF). Comparisons of CBF changes by paired image subtraction provide the opportunity to isolate cerebral areas participating in the realization of the processes that differentiate two tasks. However, the subtraction method is based on assumptions that are not entirely compatible with cerebral cognitive processing, and the derived pattern of activation specifically associated with the processes that differentiate two tasks is relative to the activation associated with the subtracted task and may therefore vary as a function of the processes actually performed in this subtracted task. To examine the implications of this procedure, a PET study with the 15O water bolus technique was carried out on normal adults. Subjects performed three tasks that made nonoverlapping cognitive processing demands: a semantic categorization of visual objects, a spatial discrimination of visually presented letters, and a phonological decision on visually presented single letters. Each task produced distinct patterns of activation consistent with evidence from neurological patients, specifically in the left occipital cortex in the semantic categorization of objects, in the parietal cortex of both hemispheres in the letter-spatial task, and in the left frontal and superior temporal cortex in the letter-sound task. However, the comparisons between the two letter tasks did not result in the expected CBF changes even though these two tasks make distinct processing requirements and are dissociable by brain injury. In addition, the phonological task resulted in activation of areas of the frontal cortex that earlier PET studies had identified as participating in semantic operations, whereas letters have no semantic property. These results suggest that the interpretation of patterns of activation is confronted with difficulties due to the automatic, and uncontrolled, processing of verbal stimuli that raises the threshold for significant CBF changes between two conditions that use the same stimuli but different task demands.
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Affiliation(s)
- J Sergent
- Montreal Neurological Institute, McGill University, Quebec, Canada
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Gottlob-McHugh SG, Lévesque M, MacKenzie K, Olson M, Yarosh O, Johnson DA. Organization of the 5S rRNA genes in the soybean Glycine max (L.) Merrill and conservation of the 5S rDNA repeat structure in higher plants. Genome 1990; 33:486-94. [PMID: 2227404 DOI: 10.1139/g90-072] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.4] [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: 12/30/2022]
Abstract
The 5S rRNA gene of the soybean Glycine max (L.) Merr. has been cloned on a 556-bp fragment of DNA and sequenced. This fragment contains two copies of the soybean 5S rDNA sequence, one intact and one truncated, separated by noncoding DNA. We have used this clone to investigate the organization of the 5S genes within the soybean genome and the extent of their methylation. Our results demonstrate that soybean 5S genes are clustered, organized into tandem repeats of 330 bp, and extensively methylated. Hybridization of the 5S sequence to Southern transfers of soybean DNA digested with BamHI reveals a striking ladderlike pattern. Hybridization of the soybean 5S sequence to a wide variety of plant DNAs results in similar patterns, suggesting that the 5S rDNA sequence, gene organization, and methylation pattern are conserved in many higher plants.
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