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Bransom L, Bassett AP, Zhou M, Cimino JX, Mailman RB, Yang Y. Dopamine D 1 Receptor Agonists Rescue Age-related Decline in Temporal Order Memory. Neuroscience 2024; 551:177-184. [PMID: 38823551 PMCID: PMC11246218 DOI: 10.1016/j.neuroscience.2024.05.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/08/2024] [Accepted: 05/27/2024] [Indexed: 06/03/2024]
Abstract
Dopamine D1 receptor agonists improve spatial working memory, but their effects on temporal order memory, particularly prone to the effects of aging, have not been studied. Two D1 agonists, PF6256142 (PF) and 2-methyldihydrexidine (2MDHX), were examined for their effects in a rodent temporal order recognition task. Our results are consistent with the hypothesis that there is an age-related decline in rodent temporal order memory. The data also show that either agonist rescues the poor memory performance with a large effective size. Interestingly, the optimal effective dose varied among individual rats of different age groups. PF showed greater potency for older rats, whereas 2MDHX showed better overall population effectiveness. Both PF and 2MDHX have high intrinsic activity at rodent D1-mediated cAMP synthesis. Conversely, at D1-mediated β-arrestin recruitment, PF has essentially no intrinsic activity, whereas 2MDHX is a super-agonist. These findings suggest that D1 agonists have potential to treat age-related cognitive decline, and the pattern of functional selectivity may be useful for developing drugs with an improved therapeutic index.
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Affiliation(s)
- Luke Bransom
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States
| | - Ava P Bassett
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States
| | - Mi Zhou
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States; Department of Neurology, Penn State University College of Medicine, Hershey, PA 17033, United States
| | - Jack X Cimino
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States
| | - Richard B Mailman
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States; Department of Neurology, Penn State University College of Medicine, Hershey, PA 17033, United States
| | - Yang Yang
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033, United States.
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2
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Shan Q, Yu X, Lin X, Tian Y. Reduced inhibitory synaptic transmission onto striatopallidal neurons may underlie aging-related motor skill deficits. Neurobiol Dis 2024; 199:106582. [PMID: 38942325 DOI: 10.1016/j.nbd.2024.106582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 06/03/2024] [Accepted: 06/25/2024] [Indexed: 06/30/2024] Open
Abstract
Human beings are living longer than ever before and aging is accompanied by an increased incidence of motor deficits, including those associated with the neurodegenerative conditions, Parkinson's disease (PD) and Huntington's disease (HD). However, the biological correlates underlying this epidemiological finding, especially the functional basis at the synapse level, have been elusive. This study reveals that motor skill performance examined via rotarod, beam walking and pole tests is impaired in aged mice. This study, via electrophysiology recordings, further identifies an aging-related reduction in the efficacy of inhibitory synaptic transmission onto dorsolateral striatum (DLS) indirect-pathway medium spiny neurons (iMSNs), i.e., a disinhibition effect on DLS iMSNs. In addition, pharmacologically enhancing the activity of DLS iMSNs by infusing an adenosine A2A receptor (A2AR) agonist, which presumably mimics the disinhibition effect, impairs motor skill performance in young mice, simulating the behavior in aged naïve mice. Conversely, pharmacologically suppressing the activity of DLS iMSNs by infusing an A2AR antagonist, in order to offset the disinhibition effect, restores motor skill performance in aged mice, mimicking the behavior in young naïve mice. In conclusion, this study identifies a functional inhibitory synaptic plasticity in DLS iMSNs that likely contributes to the aging-related motor skill deficits, which would potentially serve as a striatal synaptic basis underlying age being a prominent risk factor for neurodegenerative motor deficits.
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Affiliation(s)
- Qiang Shan
- Laboratory for Synaptic Plasticity, Shantou University Medical College, Shantou, Guangdong 515041, China.
| | - Xiaoxuan Yu
- Laboratory for Synaptic Plasticity, Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Xiaoli Lin
- Laboratory for Synaptic Plasticity, Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Yao Tian
- Chern Institute of Mathematics, Nankai University, Tianjin 300071, China
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3
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Arleo A, Bareš M, Bernard JA, Bogoian HR, Bruchhage MMK, Bryant P, Carlson ES, Chan CCH, Chen LK, Chung CP, Dotson VM, Filip P, Guell X, Habas C, Jacobs HIL, Kakei S, Lee TMC, Leggio M, Misiura M, Mitoma H, Olivito G, Ramanoël S, Rezaee Z, Samstag CL, Schmahmann JD, Sekiyama K, Wong CHY, Yamashita M, Manto M. Consensus Paper: Cerebellum and Ageing. CEREBELLUM (LONDON, ENGLAND) 2024; 23:802-832. [PMID: 37428408 PMCID: PMC10776824 DOI: 10.1007/s12311-023-01577-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/08/2023] [Indexed: 07/11/2023]
Abstract
Given the key roles of the cerebellum in motor, cognitive, and affective operations and given the decline of brain functions with aging, cerebellar circuitry is attracting the attention of the scientific community. The cerebellum plays a key role in timing aspects of both motor and cognitive operations, including for complex tasks such as spatial navigation. Anatomically, the cerebellum is connected with the basal ganglia via disynaptic loops, and it receives inputs from nearly every region in the cerebral cortex. The current leading hypothesis is that the cerebellum builds internal models and facilitates automatic behaviors through multiple interactions with the cerebral cortex, basal ganglia and spinal cord. The cerebellum undergoes structural and functional changes with aging, being involved in mobility frailty and related cognitive impairment as observed in the physio-cognitive decline syndrome (PCDS) affecting older, functionally-preserved adults who show slowness and/or weakness. Reductions in cerebellar volume accompany aging and are at least correlated with cognitive decline. There is a strongly negative correlation between cerebellar volume and age in cross-sectional studies, often mirrored by a reduced performance in motor tasks. Still, predictive motor timing scores remain stable over various age groups despite marked cerebellar atrophy. The cerebello-frontal network could play a significant role in processing speed and impaired cerebellar function due to aging might be compensated by increasing frontal activity to optimize processing speed in the elderly. For cognitive operations, decreased functional connectivity of the default mode network (DMN) is correlated with lower performances. Neuroimaging studies highlight that the cerebellum might be involved in the cognitive decline occurring in Alzheimer's disease (AD), independently of contributions of the cerebral cortex. Grey matter volume loss in AD is distinct from that seen in normal aging, occurring initially in cerebellar posterior lobe regions, and is associated with neuronal, synaptic and beta-amyloid neuropathology. Regarding depression, structural imaging studies have identified a relationship between depressive symptoms and cerebellar gray matter volume. In particular, major depressive disorder (MDD) and higher depressive symptom burden are associated with smaller gray matter volumes in the total cerebellum as well as the posterior cerebellum, vermis, and posterior Crus I. From the genetic/epigenetic standpoint, prominent DNA methylation changes in the cerebellum with aging are both in the form of hypo- and hyper-methylation, and the presumably increased/decreased expression of certain genes might impact on motor coordination. Training influences motor skills and lifelong practice might contribute to structural maintenance of the cerebellum in old age, reducing loss of grey matter volume and therefore contributing to the maintenance of cerebellar reserve. Non-invasive cerebellar stimulation techniques are increasingly being applied to enhance cerebellar functions related to motor, cognitive, and affective operations. They might enhance cerebellar reserve in the elderly. In conclusion, macroscopic and microscopic changes occur in the cerebellum during the lifespan, with changes in structural and functional connectivity with both the cerebral cortex and basal ganglia. With the aging of the population and the impact of aging on quality of life, the panel of experts considers that there is a huge need to clarify how the effects of aging on the cerebellar circuitry modify specific motor, cognitive, and affective operations both in normal subjects and in brain disorders such as AD or MDD, with the goal of preventing symptoms or improving the motor, cognitive, and affective symptoms.
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Affiliation(s)
- Angelo Arleo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Martin Bareš
- First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Brno, Czech Republic
- Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, USA
| | - Jessica A Bernard
- Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX, 77843, USA
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, TX, USA
| | - Hannah R Bogoian
- Department of Psychology, Georgia State University, Atlanta, GA, USA
| | - Muriel M K Bruchhage
- Department of Psychology, Stavanger University, Institute of Social Sciences, Kjell Arholms Gate 41, 4021, Stavanger, Norway
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Centre for Neuroimaging Sciences, Box 89, De Crespigny Park, London, PO, SE5 8AF, UK
- Rhode Island Hospital, Department for Diagnostic Imaging, 1 Hoppin St, Providence, RI, 02903, USA
- Department of Paediatrics, Warren Alpert Medical School of Brown University, 222 Richmond St, Providence, RI, 02903, USA
| | - Patrick Bryant
- Freie Universität Berlin, Fachbereich Mathematik und Informatik, Arnimallee 12, 14195, Berlin, Germany
| | - Erik S Carlson
- Department of Psychiatry and Behavioural Sciences, University of Washington, Seattle, WA, USA
- Geriatric Research, Education and Clinical Center, Veteran's Affairs Medical Center, Puget Sound, Seattle, WA, USA
| | - Chetwyn C H Chan
- Department of Psychology, The Education University of Hong Kong, New Territories, Tai Po, Hong Kong, China
| | - Liang-Kung Chen
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University College of Medicine, Taipei, Taiwan
- Center for Geriatric and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan
- Taipei Municipal Gan-Dau Hospital (managed by Taipei Veterans General Hospital), Taipei, Taiwan
| | - Chih-Ping Chung
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University College of Medicine, Taipei, Taiwan
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Vonetta M Dotson
- Department of Psychology, Georgia State University, Atlanta, GA, USA
- Gerontology Institute, Georgia State University, Atlanta, GA, USA
| | - Pavel Filip
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, USA
| | - Xavier Guell
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Christophe Habas
- CHNO Des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, 75012, Paris, France
- Université Versailles St Quentin en Yvelines, Paris, France
| | - Heidi I L Jacobs
- School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, PO BOX 616, 6200, MD, Maastricht, The Netherlands
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, PO BOX 616, 6200, MD, Maastricht, The Netherlands
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Tatia M C Lee
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Laboratory of Neuropsychology and Human Neuroscience, Department of Psychology, The University of Hong Kong, Hong Kong, China
| | - Maria Leggio
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Ataxia Laboratory, I.R.C.C.S. Santa Lucia Foundation, Rome, Italy
| | - Maria Misiura
- Department of Psychology, Georgia State University, Atlanta, GA, USA
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Giusy Olivito
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Ataxia Laboratory, I.R.C.C.S. Santa Lucia Foundation, Rome, Italy
| | - Stephen Ramanoël
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
- Université Côte d'Azur, LAMHESS, Nice, France
| | - Zeynab Rezaee
- Noninvasive Neuromodulation Unit, Experimental Therapeutics & Pathophysiology Branch, National Institute of Mental Health, NIH, Bethesda, USA
| | - Colby L Samstag
- Department of Psychiatry and Behavioural Sciences, University of Washington, Seattle, WA, USA
- Geriatric Research, Education and Clinical Center, Veteran's Affairs Medical Center, Puget Sound, Seattle, WA, USA
| | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Ataxia Center, Cognitive Behavioural neurology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kaoru Sekiyama
- Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, Japan
| | - Clive H Y Wong
- Department of Psychology, The Education University of Hong Kong, New Territories, Tai Po, Hong Kong, China
| | - Masatoshi Yamashita
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan
- United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Osaka, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium.
- Service des Neurosciences, University of Mons, Mons, Belgium.
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Shaikh UJ, Pellicano A, Schüppen A, Heinzel A, Winz OH, Herzog H, Mottaghy FM, Binkofski F. Increasing striatal dopamine release through repeated bouts of theta burst transcranial magnetic stimulation of the left dorsolateral prefrontal cortex. A 18F-desmethoxyfallypride positron emission tomography study. Front Neurosci 2024; 17:1295151. [PMID: 38304075 PMCID: PMC10833002 DOI: 10.3389/fnins.2023.1295151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/20/2023] [Indexed: 02/03/2024] Open
Abstract
Introduction Transcranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) - a Dopamine receptor-antagonist - the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured. Methods 23 healthy participants underwent two PET sessions, each one with four blocks of iTBS separated by 30 minutes: sham (control) and verum (90% of individual resting motor threshold). Receptor Binding Ratios were collected for sham and verum sessions across 37 time frames (about 130 minutes) in striatal sub-regions (Caudate nucleus and Putamen). Results Verum iTBS increased the dopamine release in striatal sub-regions, relative to sham iTBS. Dopamine levels in the verum session increased progressively across the time frames until frame number 28 (approximately 85 minutes after the start of the session and after three iTBS bouts) and then essentially remained unchanged until the end of the session. Conclusion Results suggest that the short-timed iTBS protocol performed in time-spaced blocks can effectively induce a dynamic dose dependent increase in dopaminergic fronto-striatal connectivity. This scheme could provide an alternative to unpleasant and distressing, long stimulation protocols in experimental and therapeutic settings. Specifically, it was demonstrated that three repeated bouts of iTBS, spaced by short intervals, achieve larger effects than one single stimulation. This finding has implications for the planning of therapeutic interventions, for example, treatment of major depression.
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Affiliation(s)
- Usman Jawed Shaikh
- Section Clinical Cognitive Sciences, Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | | | - Andre Schüppen
- Section Clinical Cognitive Sciences, Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Interdisciplinary Center for Clinical Research – Brain Imaging Facility, University Hospital Aachen, Aachen, Germany
| | - Alexander Heinzel
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Research Centre Juelich, Institute of Neuroscience and Medicine (INM-4), Juelich, Germany
| | - Oliver H. Winz
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Hans Herzog
- Research Centre Juelich, Institute of Neuroscience and Medicine (INM-4), Juelich, Germany
| | - Felix M. Mottaghy
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
- Juelich Aachen Research Alliance (JARA)—BRAIN, Juelich, Germany
| | - Ferdinand Binkofski
- Section Clinical Cognitive Sciences, Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Research Centre Juelich, Institute of Neuroscience and Medicine (INM-4), Juelich, Germany
- Juelich Aachen Research Alliance (JARA)—BRAIN, Juelich, Germany
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5
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Bègue I, Elandaloussi Y, Delavari F, Cao H, Moussa-Tooks A, Roser M, Coupé P, Leboyer M, Kaiser S, Houenou J, Brady R, Laidi C. The Cerebellum and Cognitive Function: Anatomical Evidence from a Transdiagnostic Sample. CEREBELLUM (LONDON, ENGLAND) 2023:10.1007/s12311-023-01645-y. [PMID: 38151675 DOI: 10.1007/s12311-023-01645-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/30/2023] [Indexed: 12/29/2023]
Abstract
Multiple lines of evidence across human functional, lesion, and animal data point to a cerebellar role, in particular of crus I, crus II, and lobule VIIB, in cognitive function. However, a mapping of distinct facets of cognitive function to cerebellar structure is missing. We analyzed structural neuroimaging data from the Healthy Brain Network (HBN). Cerebellar parcellation was performed with a validated automated segmentation pipeline (CERES) and stringent visual quality check (n = 662 subjects retained from initial n = 1452). Canonical correlation analyses (CCA) examined regional gray matter volumetric (GMV) differences in association to cognitive function (quantified with NIH Toolbox Cognition domain, NIH-TB), accounting for psychopathology severity, age, sex, scan location, and intracranial volume. Multivariate CCA uncovered a significant correlation between two components entailing a latent cognitive canonical (NIH-TB subscales) and a brain canonical variate (cerebellar GMV and intracranial volume, ICV), surviving bootstrapping and permutation procedures. The components correspond to partly shared cerebellar-cognitive function relationship with a first map encompassing cognitive flexibility (r = 0.89), speed of processing (r = 0.65), and working memory (r = 0.52) associated with regional GMV in crus II (r = 0.57) and lobule X (r = 0.59) and a second map including the crus I (r = 0.49) and lobule VI (r = 0.49) associated with working memory (r = 0.51). We show evidence for a structural subspecialization of the cerebellum topography for cognitive function in a transdiagnostic sample.
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Affiliation(s)
- Indrit Bègue
- Department of Psychiatry, Beth Israel Deaconess Medical School & Harvard Medical School, Boston, MA, USA.
- Department of Psychiatry, McLean Hospital & Harvard Medical School, Boston, MA, USA.
- Department of Psychiatry, University Hospitals of Geneva & University of Geneva, Geneva, Switzerland.
| | - Yannis Elandaloussi
- INSERM U955, Institut Mondor de La Recherche Biomédicale (IRMB), Univ. Paris Est Créteil, Equipe 15 Neuropsychiatrie Translationnelle, Créteil, France
- La Fondation Fondamental, Créteil, France
- NeuroSpin, Neuroimaging Platform, CEA, UNIACT Lab, PsyBrain Team, Saclay, France
| | - Farnaz Delavari
- Developmental Imaging and Psychopathology Laboratory, University of Geneva School of Medicine, Geneva, Switzerland
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Hengyi Cao
- Institute of Behavioral Science, Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Division of Psychiatry Research, Zucker Hillside Hospital, Queens, NY, USA
| | - Alexandra Moussa-Tooks
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mathilde Roser
- INSERM U955, Institut Mondor de La Recherche Biomédicale (IRMB), Univ. Paris Est Créteil, Equipe 15 Neuropsychiatrie Translationnelle, Créteil, France
- La Fondation Fondamental, Créteil, France
- NeuroSpin, Neuroimaging Platform, CEA, UNIACT Lab, PsyBrain Team, Saclay, France
| | - Pierrick Coupé
- LABRI UMR 5800, CNRS, Univ. Bordeaux, Bordeaux INPTalence, France
| | - Marion Leboyer
- INSERM U955, Institut Mondor de La Recherche Biomédicale (IRMB), Univ. Paris Est Créteil, Equipe 15 Neuropsychiatrie Translationnelle, Créteil, France
- La Fondation Fondamental, Créteil, France
| | - Stefan Kaiser
- Department of Psychiatry, University Hospitals of Geneva & University of Geneva, Geneva, Switzerland
| | - Josselin Houenou
- INSERM U955, Institut Mondor de La Recherche Biomédicale (IRMB), Univ. Paris Est Créteil, Equipe 15 Neuropsychiatrie Translationnelle, Créteil, France
- La Fondation Fondamental, Créteil, France
- NeuroSpin, Neuroimaging Platform, CEA, UNIACT Lab, PsyBrain Team, Saclay, France
| | - Roscoe Brady
- Department of Psychiatry, Beth Israel Deaconess Medical School & Harvard Medical School, Boston, MA, USA
| | - Charles Laidi
- INSERM U955, Institut Mondor de La Recherche Biomédicale (IRMB), Univ. Paris Est Créteil, Equipe 15 Neuropsychiatrie Translationnelle, Créteil, France.
- La Fondation Fondamental, Créteil, France.
- NeuroSpin, Neuroimaging Platform, CEA, UNIACT Lab, PsyBrain Team, Saclay, France.
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6
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Belden A, Quinci MA, Geddes M, Donovan NJ, Hanser SB, Loui P. Functional Organization of Auditory and Reward Systems in Aging. J Cogn Neurosci 2023; 35:1570-1592. [PMID: 37432735 PMCID: PMC10513766 DOI: 10.1162/jocn_a_02028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
The intrinsic organization of functional brain networks is known to change with age, and is affected by perceptual input and task conditions. Here, we compare functional activity and connectivity during music listening and rest between younger (n = 24) and older (n = 24) adults, using whole-brain regression, seed-based connectivity, and ROI-ROI connectivity analyses. As expected, activity and connectivity of auditory and reward networks scaled with liking during music listening in both groups. Younger adults show higher within-network connectivity of auditory and reward regions as compared with older adults, both at rest and during music listening, but this age-related difference at rest was reduced during music listening, especially in individuals who self-report high musical reward. Furthermore, younger adults showed higher functional connectivity between auditory network and medial prefrontal cortex that was specific to music listening, whereas older adults showed a more globally diffuse pattern of connectivity, including higher connectivity between auditory regions and bilateral lingual and inferior frontal gyri. Finally, connectivity between auditory and reward regions was higher when listening to music selected by the participant. These results highlight the roles of aging and reward sensitivity on auditory and reward networks. Results may inform the design of music-based interventions for older adults and improve our understanding of functional network dynamics of the brain at rest and during a cognitively engaging task.
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Affiliation(s)
| | | | | | - Nancy J Donovan
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA
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7
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Johansson J, Nordin K, Pedersen R, Karalija N, Papenberg G, Andersson M, Korkki SM, Riklund K, Guitart-Masip M, Rieckmann A, Bäckman L, Nyberg L, Salami A. Biphasic patterns of age-related differences in dopamine D1 receptors across the adult lifespan. Cell Rep 2023; 42:113107. [PMID: 37676765 DOI: 10.1016/j.celrep.2023.113107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/14/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023] Open
Abstract
Age-related alterations in D1-like dopamine receptor (D1DR) have distinct implications for human cognition and behavior during development and aging, but the timing of these periods remains undefined. Enabled by a large sample of in vivo assessments (n = 180, age 20 to 80 years of age, 50% female), we discover that age-related D1DR differences pivot at approximately 40 years of age in several brain regions. Focusing on the most age-sensitive dopamine-rich region, we observe opposing pre- and post-forties interrelations among caudate D1DR, cortico-striatal functional connectivity, and memory. Finally, particularly caudate D1DR differences in midlife and beyond, but not in early adulthood, associate with manifestation of white matter lesions. The present results support a model by which excessive dopamine modulation in early adulthood and insufficient modulation in aging are deleterious to brain function and cognition, thus challenging a prevailing view of monotonic D1DR function across the adult lifespan.
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Affiliation(s)
- Jarkko Johansson
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, 90187 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden.
| | - Kristin Nordin
- Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden
| | - Robin Pedersen
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, 90187 Umeå, Sweden; Wallenberg Center for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Nina Karalija
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, 90187 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden
| | - Goran Papenberg
- Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden
| | - Micael Andersson
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, 90187 Umeå, Sweden
| | - Saana M Korkki
- Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden
| | - Katrine Riklund
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, 90187 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden
| | - Marc Guitart-Masip
- Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden; Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London, UK
| | - Anna Rieckmann
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, 90187 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, 90187 Umeå, Sweden; The Munich Center for the Economics of Aging, Max Planck Institute for Social Law and Social Policy, 80799 Munich, Germany
| | - Lars Bäckman
- Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden
| | - Lars Nyberg
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, 90187 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, 90187 Umeå, Sweden; Wallenberg Center for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Alireza Salami
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 90187 Umeå, Sweden; Aging Research Center, Karolinska Institutet & Stockholm University, Tomtebodavägen 18A, 17165 Stockholm, Sweden; Department of Integrative Medical Biology, Umeå University, 90187 Umeå, Sweden; Wallenberg Center for Molecular Medicine, Umeå University, Umeå, Sweden
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8
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Pedersen R, Johansson J, Salami A. Dopamine D1-signaling modulates maintenance of functional network segregation in aging. AGING BRAIN 2023; 3:100079. [PMID: 37408790 PMCID: PMC10318303 DOI: 10.1016/j.nbas.2023.100079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/21/2023] [Accepted: 05/24/2023] [Indexed: 07/07/2023] Open
Abstract
Past research has shown that as individuals age, there are decreases in within-network connectivity and increases in between-network connectivity, a pattern known as functional dedifferentiation. While the mechanisms behind reduced network segregation are not fully understood, evidence suggests that age-related differences in the dopamine (DA) system may play a key role. The DA D1-receptor (D1DR) is the most abundant and age-sensitive receptor subtype in the dopaminergic system, known to modulate synaptic activity and enhance the specificity of the neuronal signals. In this study from the DyNAMiC project (N = 180, 20-79y), we set out to investigate the interplay among age, functional connectivity, and dopamine D1DR availability. Using a novel application of multivariate Partial Least squares (PLS), we found that older age, and lower D1DR availability, were simultaneously associated with a pattern of decreased within-network and increased between-network connectivity. Individuals who expressed greater distinctiveness of large-scale networks exhibited more efficient working memory. In line with the maintenance hypotheses, we found that older individuals with greater D1DR in caudate exhibited less dedifferentiation of the connectome, and greater working memory, compared to their age-matched counterparts with less D1DR. These findings suggest that dopaminergic neurotransmission plays an important role in functional dedifferentiation in aging with consequences for working memory function at older age.
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Affiliation(s)
- Robin Pedersen
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
- Wallenberg Center for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden
| | - Jarkko Johansson
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
- Wallenberg Center for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden
| | - Alireza Salami
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
- Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
- Wallenberg Center for Molecular Medicine (WCMM), Umeå University, Umeå, Sweden
- Aging Research Center, Karolinska Institutet & Stockholm University, Stockholm, Sweden
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9
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Colwell MJ, Tagomori H, Chapman S, Gillespie AL, Cowen PJ, Harmer CJ, Murphy SE. Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research. Transl Psychiatry 2022; 12:484. [PMID: 36396622 PMCID: PMC9671959 DOI: 10.1038/s41398-022-02249-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022] Open
Abstract
Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.
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Affiliation(s)
- Michael J Colwell
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Hosana Tagomori
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Sarah Chapman
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
| | - Amy L Gillespie
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Philip J Cowen
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Catherine J Harmer
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Susannah E Murphy
- University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK.
- Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK.
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10
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Ciampa CJ, Parent JH, Lapoint MR, Swinnerton KN, Taylor MM, Tennant VR, Whitman AJ, Jagust WJ, Berry AS. Elevated Dopamine Synthesis as a Mechanism of Cognitive Resilience in Aging. Cereb Cortex 2021; 32:2762-2772. [PMID: 34718454 DOI: 10.1093/cercor/bhab379] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
Aging is associated with declines in multiple components of the dopamine system including loss of dopamine-producing neurons, atrophy of the dopamine system's cortical targets, and reductions in the density of dopamine receptors. Countering these patterns, dopamine synthesis appears to be stable or elevated in older age. We tested the hypothesis that elevation in dopamine synthesis in aging reflects a compensatory response to neuronal loss rather than a nonspecific monotonic shift in older age. We measured individual differences in striatal dopamine synthesis capacity in cognitively normal older adults using [18F]Fluoro-l-m-tyrosine positron emission tomography cross-sectionally and tested relationships with longitudinal reductions in cortical thickness and working memory decline beginning up to 13 years earlier. Consistent with a compensation account, older adults with the highest dopamine synthesis capacity were those with greatest atrophy in posterior parietal cortex. Elevated dopamine synthesis capacity was not associated with successful maintenance of working memory performance overall, but had a moderating effect such that higher levels of dopamine synthesis capacity reduced the impact of atrophy on cognitive decline. Together, these findings support a model by which upregulation of dopamine synthesis represents a mechanism of cognitive resilience in aging.
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Affiliation(s)
- Claire J Ciampa
- Department of Psychology, Brandeis University, Waltham, MA 02453, USA
| | - Jourdan H Parent
- Department of Psychology, Brandeis University, Waltham, MA 02453, USA
| | - Molly R Lapoint
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kaitlin N Swinnerton
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Morgan M Taylor
- Department of Psychology, Brandeis University, Waltham, MA 02453, USA
| | - Victoria R Tennant
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - A J Whitman
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.,Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Anne S Berry
- Department of Psychology, Brandeis University, Waltham, MA 02453, USA
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11
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Wu C, Bendriem RM, Freed WJ, Lee CT. Transcriptome analysis of human dorsal striatum implicates attenuated canonical WNT signaling in neuroinflammation and in age-related impairment of striatal neurogenesis and synaptic plasticity. Restor Neurol Neurosci 2021; 39:247-266. [PMID: 34275915 DOI: 10.3233/rnn-211161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Motor and cognitive decline as part of the normal aging process is linked to alterations in synaptic plasticity and reduction of adult neurogenesis in the dorsal striatum. Neuroinflammation, particularly in the form of microglial activation, is suggested to contribute to these age-associated changes. OBJECTIVE AND METHODS To explore the molecular basis of alterations in striatal function during aging we analyzed RNA-Seq data for 117 postmortem human dorsal caudate samples and 97 putamen samples acquired through GTEx. RESULTS Increased expression of neuroinflammatory transcripts including TREM2, MHC II molecules HLA-DMB, HLA-DQA2, HLA-DPA1, HLA-DPB1, HLA-DMA and HLA-DRA, complement genes C1QA, C1QB, CIQC and C3AR1, and MHCI molecules HLA-B and HLA-F was identified. We also identified down-regulation of transcripts involved in neurogenesis, synaptogenesis, and synaptic pruning, including DCX, CX3CL1, and CD200, and the canonical WNTs WNT7A, WNT7B, and WNT8A. The canonical WNT signaling pathway has previously been shown to mediate adult neurogenesis and synapse formation and growth. Recent findings also highlight the link between WNT/β-catenin signaling and inflammation pathways. CONCLUSIONS These findings suggest that age-dependent attenuation of canonical WNT signaling plays a pivotal role in regulating striatal plasticity during aging. Dysregulation of WNT/β-catenin signaling via astrocyte-microglial interactions is suggested to be a novel mechanism that drives the decline of striatal neurogenesis and altered synaptic connectivity and plasticity, leading to a subsequent decrease in motor and cognitive performance with age. These findings may aid in the development of therapies targeting WNT/β-catenin signaling to combat cognitive and motor impairments associated with aging.
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Affiliation(s)
- Chun Wu
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Raphael M Bendriem
- Brain and Mind Research Institute, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - William J Freed
- Department of Biology, Lebanon Valley College, Annville, PA, USA
| | - Chun-Ting Lee
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, USA
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12
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Spontaneous Eye Blinks Predict Executive Functioning in Seniors. JOURNAL OF COGNITIVE ENHANCEMENT 2021. [DOI: 10.1007/s41465-021-00217-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractAs the world’s population is aging rapidly, cognitive training is an extensively used approach to attempt improvement of age-related cognitive functioning. With increasing numbers of older adults required to remain in the workforce, it is important to be able to reliably predict future functional decline, as well as the individual advantages of cognitive training. Given the correlation between age-related decline and striatal dopaminergic function, we investigated whether eye blink rate (EBR), a non-invasive, indirect indicator of dopaminergic activity, could predict executive functioning (response inhibition, switching and working memory updating) as well as trainability of executive functioning in older adults. EBR was collected before and after a cognitive flexibility training, cognitive training without flexibility, or a mock training. EBR predicted working memory updating performance on two measures of updating, as well as trainability of working memory updating, whereas performance and trainability in inhibition and switching tasks could not be predicted by EBR. Our findings tentatively indicate that EBR permits prediction of working memory performance in older adults. To fully interpret the relationship with executive functioning, we suggest future research should assess both EBR and dopamine receptor availability among seniors.
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13
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Matthews DC, Ritter A, Thomas RG, Andrews RD, Lukic AS, Revta C, Kinney JW, Tousi B, Leverenz JB, Fillit H, Zhong K, Feldman HH, Cummings J. Rasagiline effects on glucose metabolism, cognition, and tau in Alzheimer's dementia. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2021; 7:e12106. [PMID: 33614888 PMCID: PMC7882538 DOI: 10.1002/trc2.12106] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/09/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND A Phase II proof of concept (POC) randomized clinical trial was conducted to evaluate the effects of rasagiline, a monoamine oxidase B (MAO-B) inhibitor approved for Parkinson disease, in mild to moderate Alzheimer's disease (AD). The primary objective was to determine if 1 mg of rasagiline daily for 24 weeks is associated with improved regional brain metabolism (fluorodeoxyglucose-positron emission tomography [FDG-PET]) compared to placebo. Secondary objectives included measurement of effects on tau PET and evaluation of directional consistency of clinical end points. METHODS This was a double-blind, parallel group, placebo-controlled, community-based, three-site trial of 50 participants randomized 1:1 to receive oral rasagiline or placebo (NCT02359552). FDG-PET was analyzed for the presence of an AD-like pattern as an inclusion criterion and as a longitudinal outcome using prespecified regions of interest and voxel-based analyses. Tau PET was evaluated at baseline and longitudinally. Clinical outcomes were analyzed using an intention-to-treat (ITT) model. RESULTS Fifty patients were randomized and 43 completed treatment. The study met its primary end point, demonstrating favorable change in FDG-PET differences in rasagiline versus placebo in middle frontal (P < 0.025), anterior cingulate (P < 0.041), and striatal (P < 0.023) regions. Clinical measures showed benefit in quality of life (P < 0.04). Digit Span, verbal fluency, and Neuropsychiatric Inventory (NPI) showed non-significant directional favoring of rasagiline; no effects were observed in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog) or activities of daily living. Rasagiline was generally well tolerated with low rates of adverse events and notably fewer neuropsychiatric symptoms in the active treatment group. DISCUSSION These outcomes illustrate the potential benefits of rasagiline on clinical and neuroimaging measures in patients with mild to moderate AD. Rasagiline appears to affect neuronal activity in frontostriatal pathways, with associated clinical benefit potential warranting a more fully powered trial. This study illustrated the potential benefit of therapeutic repurposing and an experimental medicine proof-of-concept design with biomarkers to characterize patient and detect treatment response.
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Affiliation(s)
| | - Aaron Ritter
- Cleveland Clinic Lou Ruvo Center for Brain HealthLas VegasNevadaUSA
| | - Ronald G. Thomas
- Department of Family Medicine and Public HealthUCSDLa JollaCaliforniaUSA
| | | | | | - Carolyn Revta
- Alzheimer's Disease Cooperative StudyUniversity of California San Diego School of MedicineLa JollaCaliforniaUSA
| | | | - Babak Tousi
- Neurologic InstituteCleveland ClinicClevelandOhioUSA
| | | | - Howard Fillit
- Alzheimer's Drug Discovery FoundationNew YorkNew YorkUSA
| | | | - Howard H. Feldman
- Department of NeurosciencesAlzheimer's Disease Cooperative StudySan DiegoUniversity of CaliforniaLa JollaCaliforniaUSA
| | - Jeffrey Cummings
- Cleveland Clinic Lou Ruvo Center for Brain HealthLas VegasNevadaUSA
- Department of Brain HealthChambers‐Grundy Center for Transformative NeuroscienceSchool of Integrated Health SciencesUniversity of Nevada Las VegasNevadaUSA
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14
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Age-related variability in decision-making: Insights from neurochemistry. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2020; 19:415-434. [PMID: 30536205 DOI: 10.3758/s13415-018-00678-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Despite dopamine's significant role in models of value-based decision-making and findings demonstrating loss of dopamine function in aging, evidence of systematic changes in decision-making over the life span remains elusive. Previous studies attempting to resolve the neural basis of age-related alteration in decision-making have typically focused on physical age, which can be a poor proxy for age-related effects on neural systems. There is growing appreciation that aging has heterogeneous effects on distinct components of the dopamine system within subject in addition to substantial variability between subjects. We propose that some of the conflicting findings in age-related effects on decision-making may be reconciled if we can observe the underlying dopamine components within individuals. This can be achieved by incorporating in vivo imaging techniques including positron emission tomography (PET) and neuromelanin-sensitive MR. Further, we discuss how affective factors may contribute to individual differences in decision-making performance among older adults. Specifically, we propose that age-related shifts in affective attention ("positivity effect") can, in some cases, counteract the impact of altered dopamine function on specific decision-making processes, contributing to variability in findings. In an effort to provide clarity to the field and advance productive hypothesis testing, we propose ways in which in vivo dopamine imaging can be leveraged to disambiguate dopaminergic influences on decision-making, and suggest strategies for assessing individual differences in the contribution of affective attentional focus.
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15
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Turner MP, Fischer H, Sivakolundu DK, Hubbard NA, Zhao Y, Rypma B, Bäckman L. Age-differential relationships among dopamine D1 binding potential, fusiform BOLD signal, and face-recognition performance. Neuroimage 2020; 206:116232. [PMID: 31593794 DOI: 10.1016/j.neuroimage.2019.116232] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 09/26/2019] [Indexed: 11/19/2022] Open
Abstract
Facial recognition ability declines in adult aging, but the neural basis for this decline remains unknown. Cortical areas involved in face recognition exhibit lower dopamine (DA) receptor availability and lower blood-oxygen-level-dependent (BOLD) signal during task performance with advancing adult age. We hypothesized that changes in the relationship between these two neural systems are related to age differences in face-recognition ability. To test this hypothesis, we leveraged positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to measure D1 receptor binding potential (BPND) and BOLD signal during face-recognition performance. Twenty younger and 20 older participants performed a face-recognition task during fMRI scanning. Face recognition accuracy was lower in older than in younger adults, as were D1 BPND and BOLD signal across the brain. Using linear regression, significant relationships between DA and BOLD were found in both age-groups in face-processing regions. Interestingly, although the relationship was positive in younger adults, it was negative in older adults (i.e., as D1 BPND decreased, BOLD signal increased). Ratios of BOLD:D1 BPND were calculated and relationships to face-recognition performance were tested. Multiple linear regression revealed a significant Group × BOLD:D1 BPND Ratio interaction. These results suggest that, in the healthy system, synchrony between neurotransmitter (DA) and hemodynamic (BOLD) systems optimizes the level of BOLD activation evoked for a given DA input (i.e., the gain parameter of the DA input-neural activation function), facilitating task performance. In the aged system, however, desynchronization between these brain systems would reduce the gain parameter of this function, adversely impacting task performance and contributing to reduced face recognition in older adults.
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Affiliation(s)
- Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
| | - Håkan Fischer
- Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Dinesh K Sivakolundu
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Nicholas A Hubbard
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Yuguang Zhao
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lars Bäckman
- Aging Research Center, Karolinska Institute, Stockholm, Sweden
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16
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Klever L, Voudouris D, Fiehler K, Billino J. Age effects on sensorimotor predictions: What drives increased tactile suppression during reaching? J Vis 2020; 19:9. [PMID: 31426084 DOI: 10.1167/19.9.9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Tactile suppression refers to the phenomenon that tactile signals are attenuated during movement planning and execution when presented on a moving limb compared to rest. It is usually explained in the context of the forward model of movement control that predicts the sensory consequences of an action. Recent research suggests that aging increases reliance on sensorimotor predictions resulting in stronger somatosensory suppression. However, the mechanisms contributing to this age effect remain to be clarified. We measured age-related differences in tactile suppression during reaching and investigated the modulation by cognitive processes. A total of 23 younger (18-27 years) and 26 older (59-78 years) adults participated in our study. We found robust suppression of tactile signals when executing reaching movements. Age group differences corroborated stronger suppression in old age. Cognitive task demands during reaching, although overall boosting suppression effects, did not modulate the age effect. Across age groups, stronger suppression was associated with lower individual executive capacities. There was no evidence that baseline sensitivity had a prominent impact on the magnitude of suppression. We conclude that aging alters the weighting of sensory signals and sensorimotor predictions during movement control. Our findings suggest that individual differences in tactile suppression are critically driven by executive functions.
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Affiliation(s)
- Lena Klever
- Experimental Psychology, Justus Liebig University Giessen, Germany.,Center for Mind, Brain, and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | | | - Katja Fiehler
- Experimental Psychology, Justus Liebig University Giessen, Germany.,Center for Mind, Brain, and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Jutta Billino
- Experimental Psychology, Justus Liebig University Giessen, Germany.,Center for Mind, Brain, and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
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17
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Straka K, Tran ML, Millwood S, Swanson J, Kuhlman KR. Aging as a Context for the Role of Inflammation in Depressive Symptoms. Front Psychiatry 2020; 11:605347. [PMID: 33536949 PMCID: PMC7848015 DOI: 10.3389/fpsyt.2020.605347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 12/18/2020] [Indexed: 01/02/2023] Open
Abstract
Inflammation has been implicated in the pathogenesis and maintenance of depressive symptoms. The role of inflammation in depressive symptomatology may be complex, varying within endophenotypes and across the lifespan. Aging is associated with myriad changes in the structure and function of the brain. Yet, little attention has been given to the role of inflammation in depressive symptoms within a lifespan developmental framework. In this study, we examined whether the association between inflammation and depressive symptom domains varied by age. Participants were a community sample of individuals (N = 2,077, Range = 30-84) who participated in the Biomarker projects of the MIDUS2, MIDUS Refresher, or the MIDJA study. Inflammation was indexed by two inflammatory markers consistently implicated in depressed individuals, interleukin 6 (IL-6) and C-reactive protein (CRP), measured in blood. Depressive symptom domains, including depressed affect, anhedonia, somatic complaints, and interpersonal problems, were reported via the Center for Epidemiologic Studies-Depression Scale (CES-D). Inflammatory markers were associated with more somatic complaints, more interpersonal problems, and less anhedonia. Age moderated the relationship between inflammatory markers and two depressive symptom subscales. Specifically, the positive association between inflammation and somatic complaints and the negative association between inflammation and anhedonia increased with age. These observations offer preliminary evidence from a large community sample that aging may be an important context for the role of inflammatory signaling in different aspects of psychological and behavioral well-being.
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Affiliation(s)
- Kelci Straka
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States
| | - Mai-Lan Tran
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States
| | - Summer Millwood
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States
| | - James Swanson
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States
| | - Kate Ryan Kuhlman
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States.,Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, Unites States.,Interdisciplinary Institute for Salivary Bioscience Research, University of California, Irvine, Irvine, CA, United States
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18
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Dörrenbächer S, Wu C, Zimmer H, Kray J. Plasticity in brain activity dynamics after task-shifting training in older adults. Neuropsychologia 2019; 136:107285. [PMID: 31809779 DOI: 10.1016/j.neuropsychologia.2019.107285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 10/06/2019] [Accepted: 11/25/2019] [Indexed: 10/25/2022]
Abstract
Cognitive control is supported by a dynamic interplay of transient (i.e., trial-related) brain activation across fronto-parietal networks and sustained (i.e., block-related) activation across fronto-striatal networks. Older adults show disturbances in this dynamic functional recruitment. There is evidence suggesting that cognitive-control training may enable older adults to redistribute their brain activation across cortical and subcortical networks, which in turn can limit behavioral impairments. However, previous studies have only focused on spatial rather than on temporal aspects of changes in brain activation. In the present study, we examined training-related functional plasticity in old age by applying a hybrid fMRI design that sensitively tracks the spatio-temporal interactions underlying brain-activation changes. Fifty healthy seniors were assigned to a task-shifting training or an active-control group and their pretest/posttest activation-change maps were compared against 25 untrained younger adults. After training, older adults showed the same performance as untrained young adults. Compared to the control group, task-shifting training promoted proactive (i.e., early, cue-related) changes in transient mechanisms supporting the maintenance and top-down biasing of task-set representations in a specific prefrontal circuitry; reactive (i.e., late, probe-related) changes in transient mechanisms supporting response-selection processes in dissociable fronto-parietal networks; overall reductions of sustained activation in striatal circuits. Results highlight the importance of spatio-temporal interactions in training-induced neural changes in age.
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Affiliation(s)
| | - Carolyn Wu
- Saarland University, Saarbrücken, Germany; Trier University, Trier, Germany
| | | | - Jutta Kray
- Saarland University, Saarbrücken, Germany
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19
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Wang H, Zhang H. Reconsideration of Anticholinesterase Therapeutic Strategies against Alzheimer's Disease. ACS Chem Neurosci 2019; 10:852-862. [PMID: 30521323 DOI: 10.1021/acschemneuro.8b00391] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is well-known as a severe neurodegeneration disease involving complicated etiologies, and cholinesterase inhibition remain the prevailing mode of clinical intervention in AD management. Although most clinically applied cholinesterase inhibitors (ChEIs) achieve limited clinical outcomes, research on the central cholinergic system is still thriving. Recently, an impressive amount of knowledge regarding novel acetylcholinesterase functions, as well as the close association between the central cholinergic system and other key elements for AD pathogenesis, has accumulated, highlighting that this field still has great potential for future drug development. In contrast to the overwhelmingly disappointing clinical therapeutic effects of various disease-modifying drug candidates, interesting evidence has continued to emerge over the past 20 years from the wealth of preclinical and clinical data on the usage of ChEIs, indicating underestimated clinical benefits due to physician ambivalence, a lack of persistent treatment, and inappropriate medication times or doses. Here we pinpoint several topics fit for future attention, focusing on the updated cholinergic hypothesis, especially the pleiotropic relationships with key pathogenetic signaling pathways and functions in AD, as well as possible novel therapeutic strategies, including novel ChEIs and cholinesterase inhibition-based innovative multifunctional therapeutic candidates. We intend to strengthen the future value of the precise application of cholinergic drugs, especially novel ChEIs, as a cornerstone pharmacological approach to AD treatment, either alone or in combination with other targets, to relieve symptoms and to modify disease progression.
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Affiliation(s)
- Huan Wang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Haiyan Zhang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
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20
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Wolpe N, Zhang J, Nombela C, Ingram JN, Wolpert DM, Rowe JB. Sensory attenuation in Parkinson's disease is related to disease severity and dopamine dose. Sci Rep 2018; 8:15643. [PMID: 30353104 PMCID: PMC6199336 DOI: 10.1038/s41598-018-33678-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 09/25/2018] [Indexed: 01/10/2023] Open
Abstract
Abnormal initiation and control of voluntary movements are among the principal manifestations of Parkinson's disease (PD). However, the processes underlying these abnormalities and their potential remediation by dopamine treatment remain poorly understood. Normally, movements depend on the integration of sensory information with the predicted consequences of action. This integration leads to a suppression in the intensity of predicted sensations, reflected in a 'sensory attenuation'. We examined this integration process and its relation to dopamine in PD, by measuring sensory attenuation. Patients with idiopathic PD (n = 18) and population-derived controls (n = 175) matched a set of target forces applied to their left index finger by a torque motor. To match the force, participants either pressed with their right index finger ('Direct' condition) or moved a knob that controlled a motor through a linear potentiometer ('Slider' condition). We found that despite changes in sensitivity to different forces, overall sensory attenuation did not differ between medicated PD patients and controls. Importantly, the degree of attenuation was negatively related to PD motor severity but positively related to individual patient dopamine dose, as measured by levodopa dose equivalent. The results suggest that dopamine could regulate the integration of sensorimotor prediction with sensory information to facilitate the control of voluntary movements.
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Affiliation(s)
- Noham Wolpe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0SZ, UK.
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK.
- Cambridge Centre for Ageing and Neuroscience, University of Cambridge and MRC Cognition and Brain Sciences Unit, Cambridge, CB2 3EB, UK.
| | - Jiaxiang Zhang
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Cristina Nombela
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0SZ, UK
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK
| | - James N Ingram
- Cambridge Centre for Ageing and Neuroscience, University of Cambridge and MRC Cognition and Brain Sciences Unit, Cambridge, CB2 3EB, UK
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
- Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, United States
| | - Daniel M Wolpert
- Cambridge Centre for Ageing and Neuroscience, University of Cambridge and MRC Cognition and Brain Sciences Unit, Cambridge, CB2 3EB, UK
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
- Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, United States
| | - James B Rowe
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0SZ, UK
- Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK
- Cambridge Centre for Ageing and Neuroscience, University of Cambridge and MRC Cognition and Brain Sciences Unit, Cambridge, CB2 3EB, UK
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Dedifferentiation of caudate functional connectivity and striatal dopamine transporter density predict memory change in normal aging. Proc Natl Acad Sci U S A 2018; 115:10160-10165. [PMID: 30224467 DOI: 10.1073/pnas.1804641115] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Age-related changes in striatal function are potentially important for predicting declining memory performance over the adult life span. Here, we used fMRI to measure functional connectivity of caudate subfields with large-scale association networks and positron emission tomography to measure striatal dopamine transporter (DAT) density in 51 older adults (age 65-86 years) who received annual cognitive testing for up to 7 years (mean = 5.59, range 2-7 years). Analyses showed that cortical-caudate functional connectivity was less differentiated in older compared with younger adults (n = 63, age 18-32 years). Unlike in younger adults, the central lateral caudate was less strongly coupled with the frontal parietal control network in older adults. Older adults also showed less "decoupling" of the caudate from other networks, including areas of the default network (DN) and the hippocampal complex. Contrary to expectations, less decoupling between caudate and the DN was not associated with an age-related reduction of striatal DAT, suggesting that neurobiological changes in the cortex may drive dedifferentiation of cortical-caudate connectivity. Reduction of specificity in functional coupling between caudate and regions of the DN predicted memory decline over subsequent years at older ages. The age-related reduction in striatal DAT density also predicted memory decline, suggesting that a relation between striatal functions and memory decline in aging is multifaceted. Collectively, the study provides evidence highlighting the association of age-related differences in striatal function to memory decline in normal aging.
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Berry AS, Shah VD, Jagust WJ. The Influence of Dopamine on Cognitive Flexibility Is Mediated by Functional Connectivity in Young but Not Older Adults. J Cogn Neurosci 2018; 30:1330-1344. [PMID: 29791298 DOI: 10.1162/jocn_a_01286] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dopaminergic signaling in striatum is strongly implicated in executive functions including cognitive flexibility. However, there is a paucity of multimodal research in humans defining the nature of relationships between endogenous dopamine, striatal network activity, and cognition. Here, we measured dopamine synthesis capacity in young and older adults using the PET tracer 6-[18F]fluoro-l- m-tyrosine and examined its relationship with cognitive performance and functional connectivity during an fMRI study of task switching. Aging is associated with alteration in dopamine function, including profound losses in dopamine receptors but an apparent elevation in dopamine synthesis. A compensatory benefit of upregulated dopamine synthesis in aging has not been established. Across young and older adults, we found that cognitive flexibility (low behavioral switch cost) was associated with stronger task-related functional connectivity within canonical fronto-striato-thalamic circuits connecting left inferior frontal gyrus, dorsal caudate nucleus (DCA) and ventral lateral/ventral anterior thalamic nuclei. In young adults, functional connectivity mediated the influence of DCA dopamine synthesis capacity on switch cost. For older adults, these relationships were modified such that DCA synthesis capacity and connectivity interacted to influence switch cost. Older adults with most elevated synthesis capacity maintained the pattern of connectivity-cognition relationships observed in youth, whereas these relationships were not evident for older adults with low synthesis capacity. Together, these findings suggest a role of dopamine in tuning striatal circuits to benefit executive function in young adults and clarify the functional impact of elevated dopamine synthesis capacity in aging.
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23
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Paraskevoudi N, Balcı F, Vatakis A. "Walking" through the sensory, cognitive, and temporal degradations of healthy aging. Ann N Y Acad Sci 2018; 1426:72-92. [PMID: 29741265 DOI: 10.1111/nyas.13734] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/17/2018] [Accepted: 03/22/2018] [Indexed: 02/03/2023]
Abstract
As we age, there is a wide range of changes in motor, sensory, cognitive, and temporal processing due to alterations in the functioning of the central nervous and musculoskeletal systems. Specifically, aging is associated with degradations in gait; altered processing of the individual sensory systems; modifications in executive control, memory, and attention; and changes in temporal processing. These age-related alterations are often inter-related and have been suggested to result from shared neural substrates. Additionally, the overlap between these brain areas and those controlling walking raises the possibility of facilitating performance in several tasks by introducing protocols that can efficiently target all four domains. Attempts to counteract these negative effects of normal aging have been focusing on research to prevent falls and/or enhance cognitive processes, while ignoring the potential multisensory benefits accompanying old age. Research shows that the aging brain tends to increasingly rely on multisensory integration to compensate for degradations in individual sensory systems and for altered neural functioning. This review covers the age-related changes in the above-mentioned domains and the potential to exploit the benefits associated with multisensory integration in aging so as to improve one's mobility and enhance sensory, cognitive, and temporal processing.
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Affiliation(s)
- Nadia Paraskevoudi
- Multisensory and Temporal Processing Lab (MultiTimeLab), Department of History and Philosophy of Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Fuat Balcı
- Department of Psychology, Koç University, Istanbul, Turkey
| | - Argiro Vatakis
- Multisensory and Temporal Processing Lab (MultiTimeLab), Department of History and Philosophy of Science, National and Kapodistrian University of Athens, Athens, Greece
- Cognitive Systems Research Institute, Athens, Greece
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24
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Lin CH, Fan JY, Lin HI, Chang CW, Wu YR. Catechol-O-methyltransferase (COMT) genetic variants are associated with cognitive decline in patients with Parkinson's disease. Parkinsonism Relat Disord 2018; 50:48-53. [DOI: 10.1016/j.parkreldis.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/28/2018] [Accepted: 02/07/2018] [Indexed: 02/03/2023]
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Dopamine Synthesis Capacity is Associated with D2/3 Receptor Binding but Not Dopamine Release. Neuropsychopharmacology 2018; 43:1201-1211. [PMID: 28816243 PMCID: PMC5916345 DOI: 10.1038/npp.2017.180] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/07/2017] [Accepted: 08/10/2017] [Indexed: 01/08/2023]
Abstract
Positron Emission Tomography (PET) imaging allows the estimation of multiple aspects of dopamine function including dopamine synthesis capacity, dopamine release, and D2/3 receptor binding. Though dopaminergic dysregulation characterizes a number of neuropsychiatric disorders including schizophrenia and addiction, there has been relatively little investigation into the nature of relationships across dopamine markers within healthy individuals. Here we used PET imaging in 40 healthy adults to compare, within individuals, the estimates of dopamine synthesis capacity (Ki) using 6-[18F]fluoro-l-m-tyrosine ([18F]FMT; a substrate for aromatic amino acid decarboxylase), baseline D2/3 receptor-binding potential using [11C]raclopride (a weak competitive D2/3 receptor antagonist), and dopamine release using [11C]raclopride paired with oral methylphenidate administration. Methylphenidate increases synaptic dopamine by blocking the dopamine transporter. We estimated dopamine release by contrasting baseline D2/3 receptor binding and D2/3 receptor binding following methylphenidate. Analysis of relationships among the three measurements within striatal regions of interest revealed a positive correlation between [18F]FMT Ki and the baseline (placebo) [11C]raclopride measure, such that participants with greater synthesis capacity showed higher D2/3 receptor-binding potential. In contrast, there was no relationship between [18F]FMT and methylphenidate-induced [11C]raclopride displacement. These findings shed light on the nature of regulation between pre- and postsynaptic dopamine function in healthy adults, which may serve as a template from which to identify and describe alteration with disease.
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King DR, de Chastelaine M, Rugg MD. Recollection-related increases in functional connectivity across the healthy adult lifespan. Neurobiol Aging 2018; 62:1-19. [PMID: 29101898 PMCID: PMC5753578 DOI: 10.1016/j.neurobiolaging.2017.09.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 09/20/2017] [Accepted: 09/23/2017] [Indexed: 12/24/2022]
Abstract
In young adults, recollection-sensitive brain regions exhibit enhanced connectivity with a widely distributed set of other regions during successful versus unsuccessful recollection, and the magnitude of connectivity change correlates with individual differences in recollection accuracy. Here, we examined whether recollection-related changes in connectivity and their relationship with performance varied across samples of young, middle-aged, and older adults. Psychophysiological interaction analyses identified recollection-related increases in connectivity both with recollection-sensitive seed regions and among regions distributed throughout the whole brain. The seed-based approach failed to identify age-related differences in recollection-related connectivity change. However, the whole-brain analysis revealed a number of age-related effects. Numerous pairs of regions exhibited a main effect of age on connectivity change, mostly due to decreased change with increasing age. After controlling for recollection accuracy, however, these effects of age were for the most part no longer significant, and those effects that were detected now reflected age-related increases in connectivity change. A subset of pairs of regions also exhibited an age by performance interaction, driven mostly by a weaker relationship between connectivity change and recollection accuracy with increasing age. We conjecture that these effects reflect age-related differences in neuromodulation.
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Affiliation(s)
- Danielle R King
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
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Geddes MR, Mattfeld AT, Angeles CDL, Keshavan A, Gabrieli JD. Human aging reduces the neurobehavioral influence of motivation on episodic memory. Neuroimage 2017; 171:296-310. [PMID: 29274503 DOI: 10.1016/j.neuroimage.2017.12.053] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 12/17/2017] [Accepted: 12/18/2017] [Indexed: 11/25/2022] Open
Abstract
The neural circuitry mediating the influence of motivation on long-term declarative or episodic memory formation is delineated in young adults, but its status is unknown in healthy aging. We examined the effect of reward and punishment anticipation on intentional declarative memory formation for words using an event-related functional magnetic resonance imaging (fMRI) monetary incentive encoding task in twenty-one younger and nineteen older adults. At 24-hour memory retrieval testing, younger adults were significantly more likely to remember words associated with motivational cues than neutral cues. Motivational enhancement of memory in younger adults occurred only for recollection ("remember" responses) and not for familiarity ("familiar" responses). Older adults had overall diminished memory and did not show memory gains in association with motivational cues. Memory encoding associated with monetary rewards or punishments activated motivational (substantia nigra/ventral tegmental area) and memory-related (hippocampus) brain regions in younger, but not older, adults during the target word periods. In contrast, older and younger adults showed similar activation of these brain regions during the anticipatory motivational cue interval. In a separate monetary incentive delay task that did not require learning, we found evidence for relatively preserved striatal reward anticipation in older adults. This supports a potential dissociation between incidental and intentional motivational processes in healthy aging. The finding that motivation to obtain rewards and avoid punishments had reduced behavioral and neural influence on intentional episodic memory formation in older compared to younger adults is relevant to life-span theories of cognitive aging including the dopaminergic vulnerability hypothesis.
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28
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Seiffert P, Derejczyk J, Kawa J, Marcisz C, Czernek M, Szymszal J, Kapko W, Bugdol M, Torbus A, Stępień-Wyrobiec O. Frailty phenotype and the role of levodopa challenge test in geriatric inpatients with mild parkinsonian signs. Biogerontology 2017; 18:641-650. [PMID: 28612154 DOI: 10.1007/s10522-017-9716-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/07/2017] [Indexed: 12/23/2022]
Abstract
Deficiency in dopaminergic system function may be one of the hypothetical reasons of the frailty syndrome but its role still remains unclear. The aim of our study was to assess the frailty phenotype prevalence in geriatric inpatients with mild parkinsonian signs (MPS) and to investigate levodopa test in the frail patients with MPS. We examined 118 participants: 90 with MPS and 28 in control group (without MPS). The frailty syndrome presence was evaluated by the Fried criteria. Deficiency in dopaminergic system function was assessed by one of the modifications of an acute levodopa challenge test (LCT): in MPS group every patient was examined by performing Up and Go Test and also Step Test before and 3 h after taking 125 mg of Madopar (levodopa + benserazide). Sixty-nine study subjects (58%) met criteria for frailty. Fifty-five participants in MPS group (61.1% of MPS group) and fourteen (50%) in control group. All of the patients that scored positive in walk speed criterion of frailty were frail. When all MPS patients were considered, the number of components scored positive for frailty was directly related to the walk speed (r = -0.70, p < 0.0001). In MPS group LCT scores were significantly higher for frailty patients compared to non-frailty (p = 0.0027). When all MPS patients were considered, the number of components scored positive for frailty was directly related LCT score (r = 0.37, p = 0.0004). There was a relationship between LCT and walk speed (r = -0.31, p = 0.0032). Our observations provide new information about the relationship between frailty and MPS, suggest the need for increased awareness of frailty in MPS patients and conversely. Our study provides data for a discussion on pathophysiological background of the frailty syndrome (FS), emphasizing the theories of the important impact of dopaminergic system deficit and encourages further research on the role of LCT in measuring it.
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Affiliation(s)
- Piotr Seiffert
- John Paul II Geriatric Hospital, Research and Development Centre, Katowice, Poland.
| | - Jarosław Derejczyk
- John Paul II Geriatric Hospital, Research and Development Centre, Katowice, Poland
| | - Jacek Kawa
- Silesian University of Technology, Zabrze, Poland
| | - Czesław Marcisz
- Department of Gerontology and Geriatric Nursing, School of Health Sciences, Medical University of Silesia, Katowice, Poland
| | - Małgorzata Czernek
- John Paul II Geriatric Hospital, Research and Development Centre, Katowice, Poland
| | - Jan Szymszal
- Silesian University of Technology, Katowice, Poland
| | - Wojciech Kapko
- John Paul II Geriatric Hospital, Research and Development Centre, Katowice, Poland
| | | | - Anna Torbus
- John Paul II Geriatric Hospital, Research and Development Centre, Katowice, Poland
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Kälin AM, Park MTM, Chakravarty MM, Lerch JP, Michels L, Schroeder C, Broicher SD, Kollias S, Nitsch RM, Gietl AF, Unschuld PG, Hock C, Leh SE. Subcortical Shape Changes, Hippocampal Atrophy and Cortical Thinning in Future Alzheimer's Disease Patients. Front Aging Neurosci 2017; 9:38. [PMID: 28326033 PMCID: PMC5339600 DOI: 10.3389/fnagi.2017.00038] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 02/13/2017] [Indexed: 11/13/2022] Open
Abstract
Efficacy of future treatments depends on biomarkers identifying patients with mild cognitive impairment at highest risk for transitioning to Alzheimer's disease. Here, we applied recently developed analysis techniques to investigate cross-sectional differences in subcortical shape and volume alterations in patients with stable mild cognitive impairment (MCI) (n = 23, age range 59–82, 47.8% female), future converters at baseline (n = 10, age range 66–84, 90% female) and at time of conversion (age range 68–87) compared to group-wise age and gender matched healthy control subjects (n = 23, age range 61–81, 47.8% female; n = 10, age range 66–82, 80% female; n = 10, age range 68–82, 70% female). Additionally, we studied cortical thinning and global and local measures of hippocampal atrophy as known key imaging markers for Alzheimer's disease. Apart from bilateral striatal volume reductions, no morphometric alterations were found in cognitively stable patients. In contrast, we identified shape alterations in striatal and thalamic regions in future converters at baseline and at time of conversion. These shape alterations were paralleled by Alzheimer's disease like patterns of left hemispheric morphometric changes (cortical thinning in medial temporal regions, hippocampal total and subfield atrophy) in future converters at baseline with progression to similar right hemispheric alterations at time of conversion. Additionally, receiver operating characteristic curve analysis indicated that subcortical shape alterations may outperform hippocampal volume in identifying future converters at baseline. These results further confirm the key role of early cortical thinning and hippocampal atrophy in the early detection of Alzheimer's disease. But first and foremost, and by distinguishing future converters but not patients with stable cognitive abilities from cognitively normal subjects, our results support the value of early subcortical shape alterations and reduced hippocampal subfield volumes as potential markers for the early detection of Alzheimer's disease.
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Affiliation(s)
- Andrea M Kälin
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Min T M Park
- Cerebral Imaging Centre, Douglas Mental Health University InstituteMontreal, QC, Canada; Schulich School of Medicine and Dentistry, Western UniversityLondon, ON, Canada
| | - M Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Mental Health University InstituteMontreal, QC, Canada; Departments of Psychiatry and Biological and Biomedical Engineering, McGill UniversityMontreal, QC, Canada
| | - Jason P Lerch
- The Hospital for Sick ChildrenToronto, ON, Canada; Department of Medical Biophysics, The University of TorontoToronto, ON, Canada
| | - Lars Michels
- Clinic of Neuroradiology, University Hospital Zurich, University of ZurichZurich, Switzerland; Center for MR Research, University Children's Hospital ZurichZurich, Switzerland
| | - Clemens Schroeder
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Sarah D Broicher
- Neuropsychology Unit, Department of Neurology, University Hospital Zurich Zurich, Switzerland
| | - Spyros Kollias
- Clinic of Neuroradiology, University Hospital Zurich, University of Zurich Zurich, Switzerland
| | - Roger M Nitsch
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Anton F Gietl
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Paul G Unschuld
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Christoph Hock
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
| | - Sandra E Leh
- Institute for Regenerative Medicine, University of Zurich Schlieren, Switzerland
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Passow S, Thurm F, Li SC. Activating Developmental Reserve Capacity Via Cognitive Training or Non-invasive Brain Stimulation: Potentials for Promoting Fronto-Parietal and Hippocampal-Striatal Network Functions in Old Age. Front Aging Neurosci 2017; 9:33. [PMID: 28280465 PMCID: PMC5322263 DOI: 10.3389/fnagi.2017.00033] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 02/08/2017] [Indexed: 01/06/2023] Open
Abstract
Existing neurocomputational and empirical data link deficient neuromodulation of the fronto-parietal and hippocampal-striatal circuitries with aging-related increase in processing noise and declines in various cognitive functions. Specifically, the theory of aging neuronal gain control postulates that aging-related suboptimal neuromodulation may attenuate neuronal gain control, which yields computational consequences on reducing the signal-to-noise-ratio of synaptic signal transmission and hampering information processing within and between cortical networks. Intervention methods such as cognitive training and non-invasive brain stimulation, e.g., transcranial direct current stimulation (tDCS), have been considered as means to buffer cognitive functions or delay cognitive decline in old age. However, to date the reported effect sizes of immediate training gains and maintenance effects of a variety of cognitive trainings are small to moderate at best; moreover, training-related transfer effects to non-trained but closely related (i.e., near-transfer) or other (i.e., far-transfer) cognitive functions are inconsistent or lacking. Similarly, although applying different tDCS protocols to reduce aging-related cognitive impairments by inducing temporary changes in cortical excitability seem somewhat promising, evidence of effects on short- and long-term plasticity is still equivocal. In this article, we will review and critically discuss existing findings of cognitive training- and stimulation-related behavioral and neural plasticity effects in the context of cognitive aging, focusing specifically on working memory and episodic memory functions, which are subserved by the fronto-parietal and hippocampal-striatal networks, respectively. Furthermore, in line with the theory of aging neuronal gain control we will highlight that developing age-specific brain stimulation protocols and the concurrent applications of tDCS during cognitive training may potentially facilitate short- and long-term cognitive and brain plasticity in old age.
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Affiliation(s)
- Susanne Passow
- Chair of Lifespan Developmental Neuroscience, Department of Psychology, TU Dresden Dresden, Germany
| | - Franka Thurm
- Chair of Lifespan Developmental Neuroscience, Department of Psychology, TU Dresden Dresden, Germany
| | - Shu-Chen Li
- Chair of Lifespan Developmental Neuroscience, Department of Psychology, TU Dresden Dresden, Germany
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Influence of age and cognitive performance on resting-state brain networks of older adults in a population-based cohort. Cortex 2017; 89:28-44. [PMID: 28192723 DOI: 10.1016/j.cortex.2017.01.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/11/2016] [Accepted: 01/13/2017] [Indexed: 11/23/2022]
Abstract
Aging leads to global changes in brain structure and cognitive performance, with reorganization of functional brain networks. Importantly, these age-related changes show higher inter-individual variability in older subjects. To particularly address this variability is a challenge for studies on lifetime trajectories from early to late adulthood. The present study therefore had a dedicated focus on late adulthood to characterize the functional connectivity in resting-state networks (RSFC) in relation to age and cognitive performance in 711 older adults (55-85 years) from the 1000BRAINS project. The executive, left and right frontoparietal resting-state (RS) networks showed age-related increases in RSFC. However, older adults did not show changes in RSFC in the default mode network (DMN). Furthermore, lower performance in working memory (WM) was associated with higher RSFC in the left frontoparietal RS network. The results suggest age-related compensatory increases in RSFC which might help to maintain cognitive performance. Nevertheless, the negative correlation between RSFC and WM performance hints at limited cognitive reserve capacity in lower performing older adults. Consequently, the current results provide evidence for a functional reorganization of the brain until late adulthood that might additionally explain parts of the variability of cognitive abilities in older adults.
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Aging Affects Dopaminergic Neural Mechanisms of Cognitive Flexibility. J Neurosci 2016; 36:12559-12569. [PMID: 27807030 DOI: 10.1523/jneurosci.0626-16.2016] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 09/27/2016] [Accepted: 10/22/2016] [Indexed: 01/08/2023] Open
Abstract
Aging is accompanied by profound changes in the brain's dopamine system that affect cognitive function. Evidence of powerful individual differences in cognitive aging has sharpened focus on identifying biological factors underlying relative preservation versus vulnerability to decline. Dopamine represents a key target in these efforts. Alterations of dopamine receptors and dopamine synthesis are seen in aging, with receptors generally showing reduction and synthesis demonstrating increases. Using the PET tracer 6-[18F]fluoro-l-m-tyrosine, we found strong support for upregulated striatal dopamine synthesis capacity in healthy older adult humans free of amyloid pathology, relative to young people. We next used fMRI to define the functional impact of elevated synthesis capacity on cognitive flexibility, a core component of executive function. We found clear evidence in young adults that low levels of synthesis capacity were suboptimal, associated with diminished cognitive flexibility and altered frontoparietal activation relative to young adults with highest synthesis values. Critically, these relationships between dopamine, performance, and activation were transformed in older adults with higher synthesis capacity. Variability in synthesis capacity was related to intrinsic frontoparietal functional connectivity across groups, suggesting that striatal dopamine synthesis influences the tuning of networks underlying cognitive flexibility. Together, these findings define striatal dopamine's association with cognitive flexibility and its neural underpinnings in young adults, and reveal the alteration in dopamine-related neural processes in aging. SIGNIFICANCE STATEMENT Few studies have combined measurement of brain dopamine with examination of the neural basis of cognition in youth and aging to delineate the underlying mechanisms of these associations. Combining in vivo PET imaging of dopamine synthesis capacity, fMRI, and a sensitive measure of cognitive flexibility, we reveal three core findings. First, we find evidence supporting older adults' capacity to upregulate dopamine synthesis. Second, we define relationships between dopamine, cognition, and frontoparietal activity in young adults indicating high levels of synthesis capacity are optimal. Third, we demonstrate alteration of these relationships in older adults, suggesting neurochemical modulation of cognitive flexibility changes with age.
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33
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Erel H, Levy DA. Orienting of visual attention in aging. Neurosci Biobehav Rev 2016; 69:357-80. [DOI: 10.1016/j.neubiorev.2016.08.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 08/01/2016] [Accepted: 08/06/2016] [Indexed: 11/28/2022]
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Turgeon M, Lustig C, Meck WH. Cognitive Aging and Time Perception: Roles of Bayesian Optimization and Degeneracy. Front Aging Neurosci 2016; 8:102. [PMID: 27242513 PMCID: PMC4870863 DOI: 10.3389/fnagi.2016.00102] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 04/20/2016] [Indexed: 12/14/2022] Open
Abstract
This review outlines the basic psychological and neurobiological processes associated with age-related distortions in timing and time perception in the hundredths of milliseconds-to-minutes range. The difficulty in separating indirect effects of impairments in attention and memory from direct effects on timing mechanisms is addressed. The main premise is that normal aging is commonly associated with increased noise and temporal uncertainty as a result of impairments in attention and memory as well as the possible reduction in the accuracy and precision of a central timing mechanism supported by dopamine-glutamate interactions in cortico-striatal circuits. Pertinent to these findings, potential interventions that may reduce the likelihood of observing age-related declines in timing are discussed. Bayesian optimization models are able to account for the adaptive changes observed in time perception by assuming that older adults are more likely to base their temporal judgments on statistical inferences derived from multiple trials than on a single trial's clock reading, which is more susceptible to distortion. We propose that the timing functions assigned to the age-sensitive fronto-striatal network can be subserved by other neural networks typically associated with finely-tuned perceptuo-motor adjustments, through degeneracy principles (different structures serving a common function).
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Affiliation(s)
- Martine Turgeon
- Douglas Mental Health University Institute, McGill UniversityMontreal, QC, Canada
| | - Cindy Lustig
- Department of Psychology, University of MichiganAnn Arbor, MI, USA
| | - Warren H. Meck
- Department of Psychology and Neuroscience, Duke UniversityDurham, NC, USA
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Sambataro F, Podell JE, Murty VP, Das S, Kolachana B, Goldberg TE, Weinberger DR, Mattay VS. A variable number of tandem repeats in the 3′-untranslated region of the dopamine transporter modulates striatal function during working memory updating across the adult age span. Eur J Neurosci 2015; 42:1912-8. [DOI: 10.1111/ejn.12956] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 04/27/2015] [Accepted: 05/18/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Fabio Sambataro
- pRED; NORD DTA; Hoffmann-La Roche; Basel Switzerland
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
| | - Jamie E. Podell
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
| | - Vishnu P. Murty
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
| | - Saumitra Das
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
| | - Bhaskar Kolachana
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
| | - Terry E. Goldberg
- Litwin Zucker Alzheimer's Disease Research Center; Feinstein Institute; Manhasset NY USA
| | - Daniel R. Weinberger
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
- Lieber Institute for Brain Development; Johns Hopkins Medical Campus, 855 North Wolfe Street Baltimore MD 21205 USA
- Department of Psychiatry; Johns Hopkins University School of Medicine; Baltimore MD USA
- Department of Neurology; Johns Hopkins University School of Medicine; Baltimore MD USA
- Department of Neuroscience; Johns Hopkins University School of Medicine; Baltimore MD USA. Institute of Genetic Medicine; Johns Hopkins University School of Medicine; Baltimore MD USA. Lieber Institute for Brain Development; Johns Hopkins University School of Medicine; Baltimore MD USA
| | - Venkata S. Mattay
- Genes, Cognition and Psychosis Program; Clinical Brain Disorders Branch; National Institute of Mental Health Intramural Research Program; National Institutes of Health; Bethesda MD USA
- Lieber Institute for Brain Development; Johns Hopkins Medical Campus, 855 North Wolfe Street Baltimore MD 21205 USA
- Department of Neurology; Johns Hopkins University School of Medicine; Baltimore MD USA
- Lieber Institute for Brain Development; Johns Hopkins University School of Medicine; Baltimore MD USA
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Samanez-Larkin GR, Knutson B. Decision making in the ageing brain: changes in affective and motivational circuits. Nat Rev Neurosci 2015; 16:278-89. [PMID: 25873038 DOI: 10.1038/nrn3917] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
As the global population ages, older decision makers will be required to take greater responsibility for their own physical, psychological and financial well-being. With this in mind, researchers have begun to examine the effects of ageing on decision making and associated neural circuits. A new 'affect-integration-motivation' (AIM) framework may help to clarify how affective and motivational circuits support decision making. Recent research has shed light on whether and how ageing influences these circuits, providing an interdisciplinary account of how ageing can alter decision making.
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Affiliation(s)
- Gregory R Samanez-Larkin
- 1] Department of Psychology, 2 Hillhouse Avenue, Yale University, New Haven, Connecticut 06520, USA. [2]
| | - Brian Knutson
- 1] Department of Psychology, Building 420, Jordan Hall, Stanford University, Stanford, California 94305, USA. [2]
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Gard T, Taquet M, Dixit R, Hölzel BK, Dickerson BC, Lazar SW. Greater widespread functional connectivity of the caudate in older adults who practice kripalu yoga and vipassana meditation than in controls. Front Hum Neurosci 2015; 9:137. [PMID: 25852521 PMCID: PMC4360708 DOI: 10.3389/fnhum.2015.00137] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 02/27/2015] [Indexed: 11/25/2022] Open
Abstract
There has been a growing interest in understanding how contemplative practices affect brain functional organization. However, most studies have restricted their exploration to predefined networks. Furthermore, scientific comparisons of different contemplative traditions are largely lacking. Here we explored differences in whole brain resting state functional connectivity between experienced yoga practitioners, experienced meditators, and matched controls. Analyses were repeated in an independent sample of experienced meditators and matched controls. Analyses utilizing Network-Based Statistics (Zalesky et al., 2010) revealed difference components for yoga practitioners > controls and meditators > controls in which the right caudate was a central node. Follow up analyses revealed that yoga practitioners and meditators had significantly greater degree centrality in the caudate than controls. This greater degree centrality was not driven by single connections but by greater connectivity between the caudate and numerous brain regions. Findings of greater caudate connectivity in meditators than in controls was replicated in an independent dataset. These findings suggest that yoga and meditation practitioners have stronger functional connectivity within basal ganglia cortico-thalamic feedback loops than non-practitioners. Although we could not provide evidence for its mechanistic role, this greater connectivity might be related to the often reported effects of meditation and yoga on behavioral flexibility, mental health, and well-being.
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Affiliation(s)
- Tim Gard
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MAUSA
- Bender Institute of Neuroimaging, Justus Liebig Universität Giessen, GiessenGermany
- Faculty of Psychology and Neuroscience, Maastricht University, MaastrichtNetherlands
| | - Maxime Taquet
- Institute of Information and Communication Electronics and Applied Mathematics Institute, Université catholique de Louvain, Louvain-La-NeuveBelgium
| | | | - Britta K. Hölzel
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MAUSA
- Department of Neuroradiology, Klinikum Rechts der Isar, Technical University of MunichGermany
| | - Bradford C. Dickerson
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MAUSA
| | - Sara W. Lazar
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MAUSA
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Genetics and Functional Imaging: Effects of APOE, BDNF, COMT, and KIBRA in Aging. Neuropsychol Rev 2015; 25:47-62. [DOI: 10.1007/s11065-015-9279-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/20/2015] [Indexed: 01/28/2023]
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Olivito L, Saccone P, Perri V, Bachman JL, Fragapane P, Mele A, Huganir RL, De Leonibus E. Phosphorylation of the AMPA receptor GluA1 subunit regulates memory load capacity. Brain Struct Funct 2014; 221:591-603. [PMID: 25381005 PMCID: PMC4425615 DOI: 10.1007/s00429-014-0927-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/17/2014] [Indexed: 01/13/2023]
Abstract
Memory capacity (MC) refers to the number of elements one can maintain for a short retention interval. The molecular mechanisms underlying MC are unexplored. We have recently reported that mice as well as humans have a limited MC, which is reduced by hippocampal lesions. Here, we addressed the molecular mechanisms supporting MC. GluA1 AMPA-receptors (AMPA-R) mediate the majority of fast excitatory synaptic transmission in the brain and are critically involved in memory. Phosphorylation of GluA1 at serine residues S831 and S845 is promoted by CaMKII and PKA, respectively, and regulates AMPA-R function in memory duration. We hypothesized that AMPA-R phosphorylation may also be a key plastic process for supporting MC because it occurs in a few minutes, and potentiates AMPA-R ion channel function. Here, we show that knock-in mutant mice that specifically lack both of S845 and S831 phosphorylation sites on the GluA1 subunit had reduced MC in two different behavioral tasks specifically designed to assess MC in mice. This demonstrated a causal link between AMPA-R phosphorylation and MC. We then showed that information load regulates AMPA-R phosphorylation within the hippocampus, and that an overload condition associated with impaired memory is paralleled by a lack of AMPA-R phosphorylation. Accordingly, we showed that in conditions of high load, but not of low load, the pharmacological inhibition of the NMDA–CaMKII–PKA pathways within the hippocampus prevents memory as well as associated AMPA-R phosphorylation. These data provide the first identified molecular mechanism that regulates MC.
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Affiliation(s)
- Laura Olivito
- Institute of Genetics and Biophysics, CNR, Via P. Castellino 111, 80131, Naples, Italy
| | - Paola Saccone
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Valentina Perri
- Dipartimento di Biologia e Biotecnologie, Università degli Studi di Roma "La Sapienza", Rome, Italy
- Centro di Ricerca in Neurobiologia-D. Bovet, Università degli Studi di Roma "La Sapienza", Rome, Italy
| | - Julia L Bachman
- Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Hunterian 1001, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Paola Fragapane
- Istituto di Biologia e Patologia Molecolare, CNR, Rome, Italy
| | - Andrea Mele
- Dipartimento di Biologia e Biotecnologie, Università degli Studi di Roma "La Sapienza", Rome, Italy
- Centro di Ricerca in Neurobiologia-D. Bovet, Università degli Studi di Roma "La Sapienza", Rome, Italy
| | - Richard L Huganir
- Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Hunterian 1001, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Elvira De Leonibus
- Institute of Genetics and Biophysics, CNR, Via P. Castellino 111, 80131, Naples, Italy.
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
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40
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Lockhart SN, DeCarli C. Structural imaging measures of brain aging. Neuropsychol Rev 2014; 24:271-89. [PMID: 25146995 PMCID: PMC4163469 DOI: 10.1007/s11065-014-9268-3] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/05/2014] [Indexed: 01/18/2023]
Abstract
During the course of normal aging, biological changes occur in the brain that are associated with changes in cognitive ability. This review presents data from neuroimaging studies of primarily "normal" or healthy brain aging. As such, we focus on research in unimpaired or nondemented older adults, but also include findings from lifespan studies that include younger and middle aged individuals as well as from populations with prodromal or clinically symptomatic disease such as cerebrovascular or Alzheimer's disease. This review predominantly addresses structural MRI biomarkers, such as volumetric or thickness measures from anatomical images, and measures of white matter injury and integrity respectively from FLAIR or DTI, and includes complementary data from PET and cognitive or clinical testing as appropriate. The findings reveal highly consistent age-related differences in brain structure, particularly frontal lobe and medial temporal regions that are also accompanied by age-related differences in frontal and medial temporal lobe mediated cognitive abilities. Newer findings also suggest that degeneration of specific white matter tracts such as those passing through the genu and splenium of the corpus callosum may also be related to age-related differences in cognitive performance. Interpretation of these findings, however, must be tempered by the fact that comorbid diseases such as cerebrovascular and Alzheimer's disease also increase in prevalence with advancing age. As such, this review discusses challenges related to interpretation of current theories of cognitive aging in light of the common occurrence of these later-life diseases. Understanding the differences between "Normal" and "Healthy" brain aging and identifying potential modifiable risk factors for brain aging is critical to inform potential treatments to stall or reverse the effects of brain aging and possibly extend cognitive health for our aging society.
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Affiliation(s)
- Samuel N. Lockhart
- Department of Neurology and Center for Neuroscience, University of California at Davis, Sacramento, CA, USA
| | - Charles DeCarli
- Department of Neurology and Center for Neuroscience, University of California at Davis, Sacramento, CA, USA
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41
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Li SC, Rieckmann A. Neuromodulation and aging: implications of aging neuronal gain control on cognition. Curr Opin Neurobiol 2014; 29:148-58. [PMID: 25064177 DOI: 10.1016/j.conb.2014.07.009] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/13/2014] [Accepted: 07/02/2014] [Indexed: 11/17/2022]
Abstract
The efficacy of various transmitter systems declines with advancing age. Of particular interest, various pre-synaptic and post-synaptic components of the dopaminergic system change across the human lifespan; impairments in these components play important roles in cognitive deficits commonly observed in the elderly. Here, we review evidence from recent multimodal neuroimaging, pharmacological and genetic studies that have provided new insights for the associations among dopamine functions, aging, functional brain activations and behavioral performance across key cognitive functions, ranging from working memory and episodic memory to goal-directed learning and decision making. Specifically, we discuss these empirical findings in the context of an established neurocomputational theory of aging neuronal gain control. We also highlight gaps in the current understanding of dopamine neuromodulation and aging brain functions and suggest avenues for future research.
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Affiliation(s)
- Shu-Chen Li
- Lifespan Developmental Neuroscience, Department of Psychology, TU Dresden Zellescher Weg 17, Dresden D-01062, Germany; Center for Lifespan Psychology, Max Planck Institute for Human Development, Lentzeallee 94, Berlin D-14195, Germany.
| | - Anna Rieckmann
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA; Department of Radiation Sciences, Diagnostic Radiology, Umeå University, Umea 901 87, Sweden
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42
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Meusel LAC, Kansal N, Tchistiakova E, Yuen W, MacIntosh BJ, Greenwood CE, Anderson ND. A systematic review of type 2 diabetes mellitus and hypertension in imaging studies of cognitive aging: time to establish new norms. Front Aging Neurosci 2014; 6:148. [PMID: 25071557 PMCID: PMC4085499 DOI: 10.3389/fnagi.2014.00148] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/17/2014] [Indexed: 12/19/2022] Open
Abstract
The rising prevalence of type 2 diabetes (T2DM) and hypertension in older adults, and the deleterious effect of these conditions on cerebrovascular and brain health, is creating a growing discrepancy between the "typical" cognitive aging trajectory and a "healthy" cognitive aging trajectory. These changing health demographics make T2DM and hypertension important topics of study in their own right, and warrant attention from the perspective of cognitive aging neuroimaging research. Specifically, interpretation of individual or group differences in blood oxygenation level dependent magnetic resonance imaging (BOLD MRI) or positron emission tomography (PET H2O(15)) signals as reflective of differences in neural activation underlying a cognitive operation of interest requires assumptions of intact vascular health amongst the study participants. Without adequate screening, inclusion of individuals with T2DM or hypertension in "healthy" samples may introduce unwanted variability and bias to brain and/or cognitive measures, and increase potential for error. We conducted a systematic review of the cognitive aging neuroimaging literature to document the extent to which researchers account for these conditions. Of the 232 studies selected for review, few explicitly excluded individuals with T2DM (9%) or hypertension (13%). A large portion had exclusion criteria that made it difficult to determine whether T2DM or hypertension were excluded (44 and 37%), and many did not mention any selection criteria related to T2DM or hypertension (34 and 22%). Of all the surveyed studies, only 29% acknowledged or addressed the potential influence of intersubject vascular variability on the measured BOLD or PET signals. To reinforce the notion that individuals with T2DM and hypertension should not be overlooked as a potential source of bias, we also provide an overview of metabolic and vascular changes associated with T2DM and hypertension, as they relate to cerebrovascular and brain health.
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Affiliation(s)
| | - Nisha Kansal
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada
| | - Ekaterina Tchistiakova
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - William Yuen
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Bradley J MacIntosh
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Carol E Greenwood
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Nicole D Anderson
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Departments of Psychology and Psychiatry, University of Toronto Toronto, ON, Canada
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Abstract
PURPOSE OF REVIEW We present an overview of recent concepts in mechanisms underlying cognitive decline associated with brain aging and neurodegeneration from the perspective of MRI. RECENT FINDINGS Recent findings challenge the established link between neuroimaging biomarkers of neurodegeneration and age-related or disease-related cognitive decline. Amyloid burden, white matter hyperintensities and local patterns of brain atrophy seem to have differential impact on cognition, particularly on episodic and working memory - the most vulnerable domains in 'normal aging' and Alzheimer's disease. Studies suggesting that imaging biomarkers of neurodegeneration are independent of amyloid-β give rise to new hypothesis regarding the pathological cascade in Alzheimer's disease. Findings in patients with autosomal-dominant Alzheimer's disease confirm the notion of differential temporal trajectory of amyloid deposition and brain atrophy to add another layer of complexity on the basic mechanisms of cognitive aging and neurodegeneration. Finally, the concept of cognitive reserve in 'supernormal aging' is questioned by evidence for the preservation of neurochemical, structural and functional brain integrity in old age rather than recruitment of 'reserves' for maintaining cognitive abilities. SUMMARY Recent advances in clinical neuroscience, brain imaging and genetics challenge pathophysiological hypothesis of neurodegeneration and cognitive aging dominating the field in the last decade and call for reconsidering the choice of therapeutic window for early intervention.
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The impact of age on prefrontal cortex integrity during spatial working memory retrieval. Neuropsychologia 2014; 59:157-68. [PMID: 24825744 DOI: 10.1016/j.neuropsychologia.2014.04.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 04/29/2014] [Accepted: 04/30/2014] [Indexed: 11/22/2022]
Abstract
Healthy aging is accompanied by a decline in spatial working memory that is related to functional cerebral changes within the spatial working memory network. In the last decade, important findings were presented concerning the location (e.g., prefrontal), kind (e.g., 'underactivation,' 'overactivation'), and meaning (e.g., functional deficits, compensation) of these changes. Less is known about how functional connections between specific brain regions are affected by age and how these changes are related to behavioral performance. To address these issues, we used functional magnetic resonance imaging to examine retrieval-related brain activation and functional connectivity in 18 younger individuals and 18 older individuals. We assessed working memory with a modified version of the Corsi Block-Tapping test, which requires the storage and reproduction of spatial target sequences. Analyses of group differences in brain activation and functional connectivity included comparisons between younger individuals, older individuals, older high-performers, and older low-performers. In addition, we conducted a functional connectivity analysis by using a seed region approach. In comparison to younger individuals, older individuals showed lower right-hemispheric dorsolateral prefrontal activation and lower functional connectivity between the right dorsolateral prefrontal cortex and the bilateral orbitofrontal cortex. Older high-performers showed higher right dorsolateral and anterior prefrontal cortex activation than older low-performers, as well as higher functional connectivity between these brain regions. The present results suggest age-related reductions of prefrontal activation during spatial working memory retrieval. Moreover, task-related functional connectivity appears to be lower in older adults. Performance accuracy in older adults is associated with right dorsolateral and anterior prefrontal cortex activation, and with the functional connection between these regions.
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Gordon EM, Devaney JM, Bean S, Vaidya CJ. Resting-state striato-frontal functional connectivity is sensitive to DAT1 genotype and predicts executive function. ACTA ACUST UNITED AC 2013; 25:336-45. [PMID: 23968837 DOI: 10.1093/cercor/bht229] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Individual differences in striatal dopamine (DA) signaling have been associated both with individual differences in executive function in healthy individuals and with risk for psychiatric disorders defined by executive dysfunction. We used resting-state functional connectivity in 50 healthy adults to examine whether a polymorphism of the dopamine transporter gene (DAT1), which regulates striatal DA function, affects striatal functional connectivity in healthy adults, and whether that connectivity predicts executive function. We found that 9/10 heterozygotes, who are believed to have higher striatal DA signaling, demonstrated stronger connectivity between dorsal caudate (DC) and insular, dorsal anterior cingulate, and dorsolateral prefrontal regions, as well as between ventral striatum and ventrolateral prefrontal cortex, than 10/10 homozygotes. Across subjects, stronger DC-seeded connectivity predicted superior N-back working memory performance, while stronger ventral striatum-seeded connectivity predicted reduced impulsivity in everyday life. Further, mediation analysis suggested that connectivity strength mediated relationships between DAT1 genotype and behavior. These findings suggest that resting-state striato-frontal connectivity may be an endophenotype for executive function in healthy individuals.
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Affiliation(s)
- Evan M Gordon
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Joseph M Devaney
- Department of Integrative Systems Biology, Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC 20310, USA
| | - Stephanie Bean
- Department of Psychology, Georgetown University, Washington, DC 20057, USA and
| | - Chandan J Vaidya
- Department of Psychology, Georgetown University, Washington, DC 20057, USA and Children's Research Institute, Children's National Medical Center, Washington, DC 20310, USA
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46
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Abstract
Brain aging is characterized by considerable heterogeneity, including varying degrees of dysfunction in specific brain systems, notably a medial temporal lobe memory system and a frontostriatal executive system. These same systems are also affected by neurodegenerative diseases. Recent work using techniques for presymptomatic detection of disease in cognitively normal older people has shown that some of the late life alterations in cognition, neural structure, and function attributed to aging probably reflect early neurodegeneration. However, it has become clear that these same brain systems are also vulnerable to aging in the absence of even subtle disease. Thus, fundamental systemic limitations appear to confer vulnerability of these neural systems to a variety of insults, including those recognized as typical disease and those that are attributed to age. By focusing on the fundamental causes of neural system vulnerability, the prevention or treatment of a wide range of late-life neural dysfunction might be possible.
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Affiliation(s)
- William Jagust
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720-3190, USA.
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47
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Ferreira LK, Busatto GF. Resting-state functional connectivity in normal brain aging. Neurosci Biobehav Rev 2013; 37:384-400. [PMID: 23333262 DOI: 10.1016/j.neubiorev.2013.01.017] [Citation(s) in RCA: 413] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 12/17/2012] [Accepted: 01/08/2013] [Indexed: 11/24/2022]
Abstract
The world is aging and, as the elderly population increases, age-related cognitive decline emerges as a major concern. Neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), allow the investigation of the neural bases of age-related cognitive changes in vivo. Typically, fMRI studies map brain activity while subjects perform cognitive tasks, but such paradigms are often difficult to implement on a wider basis. Resting-state fMRI (rs-fMRI) has emerged as an important alternative modality of fMRI data acquisition, during which no specific task is required. Due to such simplicity and the reliability of rs-fMRI data, this modality presents increased feasibility and potential for clinical application in the future. With rs-fMRI, fluctuations in regional brain activity can be detected across separate brain regions and the patterns of intercorrelation between the functioning of these regions are measured, affording quantitative indices of resting-state functional connectivity (RSFC). This review article summarizes the results of recent rs-fMRI studies that have documented a variety of aging-related RSFC changes in the human brain, discusses the neurophysiological hypotheses proposed to interpret such findings, and provides an overview of the future, highly promising perspectives in this field.
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Affiliation(s)
- Luiz Kobuti Ferreira
- Laboratory of Psychiatric Neuroimaging (LIM-21), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, SP, Brazil.
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Ma L, Steinberg JL, Hasan KM, Narayana PA, Kramer LA, Moeller FG. Stochastic dynamic causal modeling of working memory connections in cocaine dependence. Hum Brain Mapp 2012; 35:760-78. [PMID: 23151990 DOI: 10.1002/hbm.22212] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Revised: 08/21/2012] [Accepted: 09/19/2012] [Indexed: 11/10/2022] Open
Abstract
Although reduced working memory brain activation has been reported in several brain regions of cocaine-dependent subjects compared with controls, very little is known about whether there is altered connectivity of working memory pathways in cocaine dependence. This study addresses this issue by using functional magnetic resonance imaging-based stochastic dynamic causal modeling (DCM) analysis to study the effective connectivity of 19 cocaine-dependent subjects and 14 healthy controls while performing a working memory task. Stochastic DCM is an advanced method that has recently been implemented in SPM8 that can obtain improved estimates, relative to deterministic DCM, of hidden neuronal causes before convolution with the hemodynamic response. Thus, stochastic DCM may be less influenced by the confounding effects of variations in blood oxygen level-dependent response caused by disease or drugs. Based on the significant regional activation common to both groups and consistent with previous working memory activation studies, seven regions of interest were chosen as nodes for DCM analyses. Bayesian family level inference, Bayesian model selection analyses, and Bayesian model averaging (BMA) were conducted. BMA showed that the cocaine-dependent subjects had large differences compared with the control subjects in the strengths of prefrontal-striatal modulatory (B matrix) DCM parameters. These findings are consistent with altered cortical-striatal networks that may be related to reduced dopamine function in cocaine dependence. As far as we are aware, this is the first between-group DCM study using stochastic methodology.
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Affiliation(s)
- Liangsuo Ma
- Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center, Houston, Texas
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Matthäus F, Schmidt JP, Banerjee A, Schulze TG, Demirakca T, Diener C. Effects of age on the structure of functional connectivity networks during episodic and working memory demand. Brain Connect 2012; 2:113-24. [PMID: 22698449 DOI: 10.1089/brain.2012.0077] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of the study was to investigate age-related differences in large-scale functional connectivity networks during episodic and working memory challenge. A graph theoretical approach was used providing an exhaustive set of topological measures to quantify age-related differences in the network structure on various scales. In a single session, 10 young (22-30 years) and 10 senior (62-77 years) subjects performed an episodic and a working memory task during functional magnetic resonance imaging. Networks of functional connectivity were constructed by correlating the blood oxygenation level-dependent (BOLD) signal for every pair of voxels. Statistical network parameters yield a global characterization of the network topology, the quantification of the importance of specific regions, and shifts in local connectivity. An age-related increase in the density and size of the networks and loss of small-worldness was observed, related to an expanded distribution of brain activity during both memory demands in seniors, and a more specific and localized activity in young subjects. In addition, we found highly symmetrical neural networks in young subjects accompanied by a strong coupling between parietal and occipital regions. In contrast, seniors showed pronounced left-hemispheric asymmetry with decreased connectivity within occipital areas, but increased connectivity within parietal areas. Moreover, seniors engaged an additional frontal network strongly connected to parietal areas. In contrast to young subjects, seniors showed an almost identical structure of network connectivity during both memory tasks. The chosen network approach is explorative and hypothesis-free. Our results extend seed-based and BOLD-signal intensity focused studies, and support present hypotheses like compensation and dedifferentiation.
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Affiliation(s)
- Franziska Matthäus
- Center for Modeling and Simulation in the Biosciences (BIOMS), University of Heidelberg, Heidelberg, Germany.
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Buitenweg JIV, Murre JMJ, Ridderinkhof KR. Brain training in progress: a review of trainability in healthy seniors. Front Hum Neurosci 2012; 6:183. [PMID: 22737115 PMCID: PMC3380254 DOI: 10.3389/fnhum.2012.00183] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 06/01/2012] [Indexed: 01/26/2023] Open
Abstract
The cognitive deterioration associated with aging is accompanied by structural alterations and loss of functionality of the frontostriatal dopamine system. The question arises how such deleterious cognitive effects could be countered. Brain training, currently highly popular among young and old alike, promises that users will improve on certain neurocognitive skills, and this has indeed been confirmed in a number of studies. Based on these results, it seems reasonable to expect beneficial effects of brain training in the elderly as well. A selective review of the existing literature suggests, however, that the results are neither robust nor consistent, and that transfer and sustained effects thus far appear limited. Based on this review, we argue for a series of elements that hold potential for progress in successful types of brain training: (1) including flexibility and novelty as features of the training, (2) focusing on a number of promising, yet largely unexplored domains, such as decision-making and memory strategy training, and (3) tailoring the training adaptively to the level and progress of the individual. We also emphasize the need for covariance-based MRI methods in linking structural and functional changes in the aging brain to individual differences in neurocognitive efficiency and trainability in order to further uncover the underlying mechanisms.
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Affiliation(s)
| | - Jaap M. J. Murre
- Department of Psychology, University of AmsterdamAmsterdam, Netherlands
| | - K. Richard Ridderinkhof
- Department of Psychology, University of AmsterdamAmsterdam, Netherlands
- Cognitive Science Center Amsterdam, University of AmsterdamAmsterdam, Netherlands
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