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Picó-Pérez M, Magalhães R, Esteves M, Vieira R, Castanho TC, Amorim L, Sousa M, Coelho A, Moreira PS, Cunha RA, Sousa N. Coffee consumption decreases the connectivity of the posterior Default Mode Network (DMN) at rest. Front Behav Neurosci 2023; 17:1176382. [PMID: 37448789 PMCID: PMC10336217 DOI: 10.3389/fnbeh.2023.1176382] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/11/2023] [Indexed: 07/15/2023] Open
Abstract
Habitual coffee consumers justify their life choices by arguing that they become more alert and increase motor and cognitive performance and efficiency; however, these subjective impressions still do not have a neurobiological correlation. Using functional connectivity approaches to study resting-state fMRI data in a group of habitual coffee drinkers, we herein show that coffee consumption decreased connectivity of the posterior default mode network (DMN) and between the somatosensory/motor networks and the prefrontal cortex, while the connectivity in nodes of the higher visual and the right executive control network (RECN) is increased after drinking coffee; data also show that caffeine intake only replicated the impact of coffee on the posterior DMN, thus disentangling the neurochemical effects of caffeine from the experience of having a coffee.
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Affiliation(s)
- Maria Picó-Pérez
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
- Departamento de Psicología Básica, Clínica y Psicobiología, Universitat Jaume I, Castellón de la Plana, Spain
| | - Ricardo Magalhães
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
| | - Madalena Esteves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
| | - Rita Vieira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
| | - Teresa C. Castanho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
- P5 Medical Center, Braga, Portugal
| | - Liliana Amorim
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
- P5 Medical Center, Braga, Portugal
| | - Mafalda Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
| | - Ana Coelho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
| | - Pedro S. Moreira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Psychological Neuroscience Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal
| | - Rodrigo A. Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimaraes, Portugal
- Clinical Academic Center – Braga, Braga, Portugal
- P5 Medical Center, Braga, Portugal
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2
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Fu S, Liang S, Lin C, Wu Y, Xie S, Li M, Lei Q, Li J, Yu K, Yin Y, Hua K, Li W, Wu C, Ma X, Jiang G. Aberrant brain entropy in posttraumatic stress disorder comorbid with major depressive disorder during the coronavirus disease 2019 pandemic. Front Psychiatry 2023; 14:1143780. [PMID: 37333934 PMCID: PMC10272369 DOI: 10.3389/fpsyt.2023.1143780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/09/2023] [Indexed: 06/20/2023] Open
Abstract
Aim Previously, neuroimaging studies on comorbid Posttraumatic-Major depression disorder (PTSD-MDD) comorbidity found abnormalities in multiple brain regions among patients. Recent neuroimaging studies have revealed dynamic nature on human brain activity during resting state, and entropy as an indicator of dynamic regularity may provide a new perspective for studying abnormalities of brain function among PTSD-MDD patients. During the COVID-19 pandemic, there has been a significant increase in the number of patients with PTSD-MDD. We have decided to conduct research on resting-state brain functional activity of patients who developed PTSD-MDD during this period using entropy. Methods Thirty three patients with PTSD-MDD and 36 matched TCs were recruited. PTSD and depression symptoms were assessed using multiple clinical scales. All subjects underwent functional magnetic resonance imaging (fMRI) scans. And the brain entropy (BEN) maps were calculated using the BEN mapping toolbox. A two-sample t-test was used to compare the differences in the brain entropy between the PTSD-MDD comorbidity group and TC group. Furthermore, correlation analysis was conducted between the BEN changes in patients with PTSD-MDD and clinical scales. Results Compared to the TCs, PTSD-MDD patients had a reduced BEN in the right middle frontal orbital gyrus (R_MFOG), left putamen, and right inferior frontal gyrus, opercular part (R_IFOG). Furthermore, a higher BEN in the R_MFOG was related to higher CAPS and HAMD-24 scores in the patients with PTSD-MDD. Conclusion The results showed that the R_MFOG is a potential marker for showing the symptom severity of PTSD-MDD comorbidity. Consequently, PTSD-MDD may have reduced BEN in frontal and basal ganglia regions which are related to emotional dysregulation and cognitive deficits.
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Affiliation(s)
- Shishun Fu
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Sipei Liang
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Chulan Lin
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yunfan Wu
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Shuangcong Xie
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Meng Li
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Qiang Lei
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Jianneng Li
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Kanghui Yu
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yi Yin
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Kelei Hua
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Wuming Li
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Caojun Wu
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Xiaofen Ma
- The Department of Nuclear Medicine, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Guihua Jiang
- The Department of Medical Imaging Guangdong Second Provincial General Hospital, Guangzhou, China
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Williams RJ, Specht JL, Mazerolle EL, Lebel RM, MacDonald ME, Pike GB. Correspondence between BOLD fMRI task response and cerebrovascular reactivity across the cerebral cortex. Front Physiol 2023; 14:1167148. [PMID: 37228813 PMCID: PMC10203231 DOI: 10.3389/fphys.2023.1167148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
BOLD sensitivity to baseline perfusion and blood volume is a well-acknowledged fMRI confound. Vascular correction techniques based on cerebrovascular reactivity (CVR) might reduce variance due to baseline cerebral blood volume, however this is predicated on an invariant linear relationship between CVR and BOLD signal magnitude. Cognitive paradigms have relatively low signal, high variance and involve spatially heterogenous cortical regions; it is therefore unclear whether the BOLD response magnitude to complex paradigms can be predicted by CVR. The feasibility of predicting BOLD signal magnitude from CVR was explored in the present work across two experiments using different CVR approaches. The first utilized a large database containing breath-hold BOLD responses and 3 different cognitive tasks. The second experiment, in an independent sample, calculated CVR using the delivery of a fixed concentration of carbon dioxide and a different cognitive task. An atlas-based regression approach was implemented for both experiments to evaluate the shared variance between task-invoked BOLD responses and CVR across the cerebral cortex. Both experiments found significant relationships between CVR and task-based BOLD magnitude, with activation in the right cuneus (R 2 = 0.64) and paracentral gyrus (R 2 = 0.71), and the left pars opercularis (R 2 = 0.67), superior frontal gyrus (R 2 = 0.62) and inferior parietal cortex (R 2 = 0.63) strongly predicted by CVR. The parietal regions bilaterally were highly consistent, with linear regressions significant in these regions for all four tasks. Group analyses showed that CVR correction increased BOLD sensitivity. Overall, this work suggests that BOLD signal response magnitudes to cognitive tasks are predicted by CVR across different regions of the cerebral cortex, providing support for the use of correction based on baseline vascular physiology.
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Affiliation(s)
- Rebecca J. Williams
- Faculty of Health, School of Human Services, Charles Darwin University, Darwin, NT, Australia
| | - Jacinta L. Specht
- Department of Clinical Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Erin L. Mazerolle
- Departments of Psychology and Computer Science, St. Francis Xavier University, Antigonish, NS, Canada
| | - R. Marc Lebel
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- GE HealthCare, Calgary, AB, Canada
| | - M. Ethan MacDonald
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada
- Department of Electrical and Software Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada
| | - G. Bruce Pike
- Department of Clinical Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Peng SL, Chu LWL, Su FY. Cerebral hemodynamic response to caffeine: effect of dietary caffeine consumption. NMR IN BIOMEDICINE 2022; 35:e4727. [PMID: 35285102 DOI: 10.1002/nbm.4727] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/14/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
Caffeine has a significant effect on cerebrovascular systems, and the dual action of caffeine on both neural and vascular responses leads to concerns for the interpretation of blood oxygenation level-dependent (BOLD) functional MRI. However, potential differences in the brain response to caffeine with regard to consumption habits have not been fully elucidated, as BOLD responses may vary with the dietary caffeine consumption history. The main aim of this study was to characterize the acute effect of caffeine on cerebral hemodynamic responses in participants with different patterns of caffeine consumption habits. Fifteen non-habitual and 11 habitual volunteers were included in this study. The cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to the breath-hold challenge were measured before and after 200 mg caffeine administration. The non-habitual individuals exhibited a pattern of progressive reduction in CBF with time. The CVR was diminished in the caffeinated condition (P < 0.05). In the habitual group, the pattern of CBF decrease was smaller and homogeneous across the brain, and reached steady state rapidly. The CVR was not affected in the presence of caffeine (P > 0.05). Our results demonstrated that the cerebral hemodynamic response to caffeine was subject to the habitual consumption patterns of the participants. The compromised CVR following caffeine administration in the non-habitual group may partially explain the suppressed BOLD response to a visual stimulation in low-caffeine-level users.
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Affiliation(s)
- Shin-Lei Peng
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Lok Wang Lauren Chu
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Feng-Yi Su
- Department of Medical Imaging, China Medical University Hospital, Taichung, Taiwan
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Daubner J, Arshaad MI, Henseler C, Hescheler J, Ehninger D, Broich K, Rawashdeh O, Papazoglou A, Weiergräber M. Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives. Neural Plast 2021; 2021:8823383. [PMID: 33519929 PMCID: PMC7817276 DOI: 10.1155/2021/8823383] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 12/15/2020] [Accepted: 12/30/2020] [Indexed: 11/17/2022] Open
Abstract
Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, β-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.
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Affiliation(s)
- Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Muhammad Imran Arshaad
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, Faculty of Medicine, Robert-Koch-Str. 39, 50931 Cologne, Germany
| | - Dan Ehninger
- Molecular and Cellular Cognition, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Oliver Rawashdeh
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
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6
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Shih CT, Chiu SC, Peng SL. Caffeine enhances BOLD responses to electrical whisker pad stimulation in rats during alpha-chloralose anaesthesia. Eur J Neurosci 2020; 53:601-610. [PMID: 32926471 DOI: 10.1111/ejn.14968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 09/01/2020] [Indexed: 12/28/2022]
Abstract
By reducing the cerebral blood flow and thereby increasing the resting deoxyhaemoglobin concentration, many human studies have shown that caffeine has a beneficial effect on enhancing the magnitude of blood-oxygenation-level-dependent (BOLD) responses. However, the effect of caffeine on BOLD responses in animals under anaesthesia has not been demonstrated. In this study, we aimed to determine the effect of systemic caffeine administration on BOLD responses in rats under alpha-chloralose. By applying electric whisker pad stimulation to male Sprague-Dawley rats, we performed fMRI measurements before and after the caffeine injection (40 mg/kg, n = 7) or an equivalent volume of saline (n = 6) at 7T. To understand the potential perturbation of animal physiology during stimulation, arterial blood pressure was measured in a separate group of animals (n = 3) outside the scanner. Caffeine significantly decreased baseline BOLD signals (p = .05) due to the increased deoxyhaemoglobin level. Both BOLD responses and t-values in the primary somatosensory cortex were significantly increased (both p < .05). The blood pressure changed insignificantly (p > .05). No significant differences in BOLD responses and t-values were observed in the control condition of saline injection (both p > .05). These findings suggested that, although the cerebral activity was lower under alpha-chloralose anaesthesia, the higher level of deoxygemoglobin at the baseline under the caffeinated condition can benefit the magnitude of BOLD responses in rats. These findings suggest that animal models might serve as potential platforms for further caffeine-related fMRI research studies.
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Affiliation(s)
- Cheng-Ting Shih
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Shao-Chieh Chiu
- Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shin-Lei Peng
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
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Kim JH, Taylor AJ, Wang DJJ, Zou X, Ress D. Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex. J Cereb Blood Flow Metab 2020; 40:1823-1837. [PMID: 31429358 PMCID: PMC7446561 DOI: 10.1177/0271678x19869034] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal depends on an interplay of cerebral blood flow (CBF), oxygen metabolism, and cerebral blood volume. Despite wide usage of BOLD fMRI, it is not clear how these physiological components create the BOLD signal. Here, baseline CBF and its dynamics evoked by a brief stimulus (2 s) in human visual cortex were measured at 3T. We found a stereotypical CBF response: immediate increase, rising to a peak a few second after the stimulus, followed by a significant undershoot. The BOLD hemodynamic response function (HRF) was also measured in the same session. Strong correlations between HRF and CBF peak responses indicate that the flow responses evoked by neural activation in nearby gray matter drive the early HRF. Remarkably, peak CBF and HRF were also strongly modulated by baseline perfusion. The CBF undershoot was reliable and significantly correlated with the HRF undershoot. However, late-time dynamics of the HRF and CBF suggest that oxygen metabolism can also contribute to the HRF undershoot. Combined measurement of the CBF and HRF for brief neural activation is a useful tool to understand the temporal dynamics of neurovascular and neurometabolic coupling.
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Affiliation(s)
- Jung Hwan Kim
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Amanda J Taylor
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Danny JJ Wang
- Laboratory of FMRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Xiaowei Zou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - David Ress
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- David Ress, Baylor College of Medicine, 1 Baylor Plaza T115E, Houston, TX 77030, USA.
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Phillips TJ, Gom RC, Wolff MD, Teskey GC. Caffeine Exacerbates Postictal Hypoxia. Neuroscience 2019; 422:32-43. [PMID: 31678341 DOI: 10.1016/j.neuroscience.2019.09.025] [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: 06/22/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022]
Abstract
A stroke-like event follows seizures which may be responsible for the postictal state and a contributing factor to the development of seizure-induced brain abnormalities and behavioral dysfunction associated with epilepsy. Caffeine is the world's most popular drug with ∼85% of people in the USA consuming it daily. Thus, persons with epilepsy are likely to have caffeine in their body and brain during seizures. This preclinical study investigated the effects of acute caffeine on local hippocampal tissue oxygenation pre and post seizure. We continuously measured local oxygen levels in the CA1 region of the hippocampus and utilized the electrical kindling model in rats. Rats were acutely administered either caffeine, or one of its metabolites, or agonists and antagonists at adenosine sub-receptor types or ryanodine receptors prior to the elicitation of seizures. Acute caffeine administration caused a significant drop in pre-seizure hippocampal pO2. Following a seizure, caffeine, as well as two of its metabolites paraxanthine, and theophylline, increased the time below the severe hypoxic threshold (10 mmHg). Likewise, the specific A2A receptor antagonist, SCH-58261, mimicked caffeine by causing a significant drop in pre-seizure pO2 and the area and time below the severe hypoxic threshold. Moreover, the A2A receptor agonist, CGS-21680 was able to prevent the effect of both caffeine and SCH-58261 adding further evidence that caffeine is likely acting through the A2A receptor. Clinical tracking and investigations are needed to determine the effect of caffeine on postictal symptomology and blood flow in persons with epilepsy.
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Affiliation(s)
- Thomas J Phillips
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Renaud C Gom
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marshal D Wolff
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - G Campbell Teskey
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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9
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Yang Y, Lin X, Li J, Han L, Li Z, Liu S, Hou G, Xie C, Lv X, Qiu Y. Aberrant Brain Activity at Early Delay Stage Post-radiotherapy as a Biomarker for Predicting Neurocognitive Dysfunction Late-Delayed in Patients With Nasopharyngeal Carcinoma. Front Neurol 2019; 10:752. [PMID: 31379710 PMCID: PMC6660255 DOI: 10.3389/fneur.2019.00752] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/27/2019] [Indexed: 12/24/2022] Open
Abstract
Background: Increasing evidence indicates that early radiation-induced subtle cerebral changes may be the precursors to permanent brain dysfunction at the late-delayed (LDS) post-radiotherapy (RT) stage. In this study, we aim to track the RT-related longitudinal brain activity in nasopharyngeal carcinoma (NPC) patients and to determine whether early abnormal brain activity can predict late neurocognitive dysfunction after RT. Methods: Thirty-three NPC patients were finally included and longitudinally followed up at the following time points: prior to treatment initiation, early-delayed stage (EDS, 1-3 months), and LDS (six months) after RT. Fifteen comparable healthy controls (HCs) were finally included and followed up in parallel. Montreal Cognitive Assessment (MoCA) was used to assess the general cognitive function. Brain activity was recorded via resting-state fMRI and regional homogeneity (ReHo). A whole-brain voxel-wise-based one-way repeated-measure analysis of variance (ANOVA) was conducted to evaluate the longitudinal ReHo changes among the three time points for NPC patients and HCs, respectively. Results were reported at the significant level of a threshold of two-tailed voxel-wise P < 0.01 and cluster level P < 0.05 with Gaussian Random Field (GRF) correction. Finally, the efficacies of the aberrant ReHo at EDS for predicting the cognitive impairment at LDS in NPC patients were evaluated. Results: Significant differences were detected in ReHo among the three time points in NPC patients but not in HCs. Aberrant ReHo was distributed in the bilateral cerebellum, the right temporal lobe, and the left insular areas, which showed different dynamic changes patterns over time. Logistic regression model combining the mean ReHo, age, and irradiation dose on the bilateral temporal lobe had the highest diagnostic efficiency according to the area under the curve (AUC) score (AUC = 0.752, P = 0.023). Conclusions: The post-RT brain activity revealed by ReHo in NPC patients was dynamic, complex, and multifactorial. Furthermore, the combination of the aberrant ReHo at EDS, age, and irradiation dose may serve as a potential biomarker of the RT-induced cognitive impairments at LDS.
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Affiliation(s)
- Yadi Yang
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Xiaoshan Lin
- Department of Radiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
| | - Jing Li
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Lujun Han
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Zhipeng Li
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Shiliang Liu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Gangqiang Hou
- Shenzhen Kangning Hospital, Shenzhen Mental Health Center, Shenzhen, China
| | - Chuanmiao Xie
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Xiaofei Lv
- Department of Medical Imaging, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China
| | - Yingwei Qiu
- Department of Radiology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
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10
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Mitko A, Rothlein D, Poole V, Robinson M, McGlinchey R, DeGutis J, Salat D, Esterman M. Individual differences in sustained attention are associated with cortical thickness. Hum Brain Mapp 2019; 40:3243-3253. [PMID: 30980462 DOI: 10.1002/hbm.24594] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 01/10/2023] Open
Abstract
Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta-analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention performance. Sustained attention was measured using the gradual onset continuous performance task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high-resolution structural MRI scans. Whole-brain vertex-wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network-based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.
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Affiliation(s)
- Alex Mitko
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts
| | - David Rothlein
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts
| | - Victoria Poole
- Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts.,Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Meghan Robinson
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts.,Geriatric Research Education and Clinical Center (GRECC), Boston Division VA Healthcare System, Boston, Massachusetts.,Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
| | - Regina McGlinchey
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts.,Geriatric Research Education and Clinical Center (GRECC), Boston Division VA Healthcare System, Boston, Massachusetts.,Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Joseph DeGutis
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Geriatric Research Education and Clinical Center (GRECC), Boston Division VA Healthcare System, Boston, Massachusetts.,Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - David Salat
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts.,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts.,Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Michael Esterman
- Translational Research Center for TBI and Stress Disorders (TRACTS), VA RR&D TBI National Research Center, VA Boston Healthcare System, Boston, Massachusetts.,Neuroimaging Research for Veterans (NeRVe) Center, VA Boston Healthcare System, Boston, Massachusetts.,Geriatric Research Education and Clinical Center (GRECC), Boston Division VA Healthcare System, Boston, Massachusetts.,Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts
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11
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Yang HCS, Liang Z, Yao JF, Shen X, Frederick BD, Tong Y. Vascular effects of caffeine found in BOLD fMRI. J Neurosci Res 2018; 97:456-466. [PMID: 30488978 DOI: 10.1002/jnr.24360] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/11/2022]
Abstract
The blood oxygen level-dependent (BOLD) signal in functional magnetic resonance imaging (fMRI) measures neuronal activation indirectly. Previous studies have found aperiodic, systemic low-frequency oscillations (sLFOs, ~0.1 Hz) in BOLD signals from resting state (RS) fMRI, which reflects the non-neuronal cerebral perfusion information. In this study, we investigated the possibility of extracting vascular information from the sLFOs in RS BOLD fMRI, which could provide complementary information to the neuronal activations. Two features of BOLD signals were exploited. First, time delays between the sLFOs of big blood vessels and brain voxels were calculated to determine cerebral circulation times and blood arrival times. Second, voxel-wise standard deviations (SD) of LFOs were calculated to represent the blood densities. We explored those features on the publicly available Myconnectome data set (a 2-year study of an individual subject (Male)), which contains 45 RS scans acquired after the subject had coffee, and 45 coffee-free RS scans, acquired on different days. Our results showed that shorter time delays and smaller SDs were detected in caffeinated scans. This is consistent with the vasoconstriction effects of caffeine, which leads to increased blood flow velocity. We also compared our results with previous findings on neuronal networks from the same data set. Our finding showed that brain regions with the significant vascular effect of caffeine coincide with those with a significant neuronal effect, indicating close interaction. This study provides methods to assess the physiological information from RS fMRI. Together with the neuronal information, we can study simultaneously the underlying correlations and interactions between vascular and neuronal networks, especially in pharmacological studies.
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Affiliation(s)
- Ho-Ching Shawn Yang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Zhenhu Liang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,Institute of Electrical Engineering, Yanshan University, Qinhuangdao, China
| | - Jinxia Fiona Yao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Xin Shen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Blaise deB Frederick
- McLean Imaging Center, McLean Hospital, Belmont, Massachusetts.,Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Yunjie Tong
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
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12
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Hosford PS, Gourine AV. What is the key mediator of the neurovascular coupling response? Neurosci Biobehav Rev 2018; 96:174-181. [PMID: 30481531 PMCID: PMC6331662 DOI: 10.1016/j.neubiorev.2018.11.011] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/11/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022]
Abstract
Cellular and molecular mechanisms underlying increases in regional blood flow in response to neuronal activity are not fully understood. We have compared the effects of 79 in vivo and 36 in vitro experimental attempts to inhibit the neurovascular response. Blockade of neuronal NO synthase (nNOS) has the largest effect of any individual target, reducing the neurovascular response by 64%. This points to the existence of an unknown key signalling mechanism which accounts for approximately one third of the neurovascular response.
The mechanisms of neurovascular coupling contribute to ensuring brain energy supply is sufficient to meet demand. Despite significant research interest, the mechanisms underlying increases in regional blood flow that follow heightened neuronal activity are not completely understood. This article presents a systematic review and analysis of published data reporting the effects of pharmacological or genetic blockade of all hypothesised signalling pathways of neurovascular coupling. Our primary outcome measure was the percent reduction of the neurovascular response assessed using in vivo animal models. Selection criteria were met by 50 primary sources reporting the effects of 79 treatments. Experimental conditions were grouped into categories targeting mechanisms mediated by nitric oxide (NO), prostanoids, purines, potassium, amongst others. Blockade of neuronal NO synthase was found to have the largest effect of inhibiting any individual target, reducing the neurovascular response by 64% (average of 11 studies). Inhibition of multiple targets in combination with nNOS blockade had no further effect. This analysis points to the existence of an unknown signalling mechanism accounting for approximately one third of the neurovascular response.
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Affiliation(s)
- Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK; William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, UK.
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & Pharmacology, University College London, London, UK.
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13
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Joris PJ, Mensink RP, Adam TC, Liu TT. Cerebral Blood Flow Measurements in Adults: A Review on the Effects of Dietary Factors and Exercise. Nutrients 2018; 10:nu10050530. [PMID: 29693564 PMCID: PMC5986410 DOI: 10.3390/nu10050530] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/11/2018] [Accepted: 04/23/2018] [Indexed: 12/22/2022] Open
Abstract
Improving cerebrovascular function may be a key mechanism whereby a healthy lifestyle, of which a healthy diet combined with increased physical activity levels is a cornerstone, protects against cognitive impairments. In this respect, effects on cerebral blood flow (CBF)—a sensitive physiological marker of cerebrovascular function—are of major interest. This review summarizes the impact of specific dietary determinants and physical exercise on CBF in adults and discusses the relation between these effects with potential changes in cognitive function. A limited number of randomized controlled trials have already demonstrated the beneficial effects of an acute intake of nitrate and polyphenols on CBF, but evidence for a relationship between these effects as well as improvements in cognitive functioning is limited. Moreover, long-term trans-resveratrol supplementation has been shown to increase CBF in populations at increased risk of accelerated cognitive decline. Long-term supplementation of n-3 long-chain polyunsaturated fatty acids may also increase CBF, but related effects on cognitive performance have not yet been found. Significant decreases in cerebral perfusion were observed by commonly consumed amounts of caffeine, while alcohol intake was shown to increase CBF in a dose-dependent way. However, the long-term effects are not clear. Finally, long-term exercise training may be a promising approach to improve CBF, as increases in perfusion may contribute to the beneficial effects on cognitive functioning observed following increased physical activity levels.
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Affiliation(s)
- Peter J Joris
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands.
| | - Ronald P Mensink
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands.
| | - Tanja C Adam
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands.
| | - Thomas T Liu
- Center for Functional Magnetic Resonance Imaging (MRI), University of California San Diego, La Jolla, CA 92093-0677, USA.
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14
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Caffeine Caused a Widespread Increase of Resting Brain Entropy. Sci Rep 2018; 8:2700. [PMID: 29426918 PMCID: PMC5807546 DOI: 10.1038/s41598-018-21008-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/29/2018] [Indexed: 11/09/2022] Open
Abstract
Entropy is an important trait of brain function and high entropy indicates high information processing capacity. We recently demonstrated that brain entropy (BEN) is stable across time and differs between controls and patients with various brain disorders. The purpose of this study was to examine whether BEN is sensitive to pharmaceutical modulations with caffeine. Both cerebral blood flow (CBF) and resting fMRI were collected from sixty caffeine-naïve healthy subjects before and after taking a 200 mg caffeine pill. Our data showed that caffeine reduced CBF in the whole brain but increased BEN across the cerebral cortex with the highest increase in lateral prefrontal cortex, the default mode network (DMN), visual cortex, and motor network, consistent with the beneficial effects of caffeine (such as vigilance and attention) on these areas. BEN increase was correlated to CBF reduction only in several regions (-0.5 < r < -0.4), indicating a neuronal nature for most of the observed BEN alterations. In summary, we showed the first evidence of BEN alterations due to caffeine ingestion, suggesting BEN as a biomarker sensitive to pharmaceutical brain function modulations.
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15
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Silva MA, See AP, Essayed WI, Golby AJ, Tie Y. Challenges and techniques for presurgical brain mapping with functional MRI. NEUROIMAGE-CLINICAL 2017; 17:794-803. [PMID: 29270359 PMCID: PMC5735325 DOI: 10.1016/j.nicl.2017.12.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/10/2017] [Accepted: 12/05/2017] [Indexed: 01/22/2023]
Abstract
Functional magnetic resonance imaging (fMRI) is increasingly used for preoperative counseling and planning, and intraoperative guidance for tumor resection in the eloquent cortex. Although there have been improvements in image resolution and artifact correction, there are still limitations of this modality. In this review, we discuss clinical fMRI's applications, limitations and potential solutions. These limitations depend on the following parameters: foundations of fMRI, physiologic effects of the disease, distinctions between clinical and research fMRI, and the design of the fMRI study. We also compare fMRI to other brain mapping modalities which should be considered as alternatives or adjuncts when appropriate, and discuss intraoperative use and validation of fMRI. These concepts direct the clinical application of fMRI in neurosurgical patients. fMRI is increasingly used for presurgical brain mapping for surgical planning. Understanding of the limitations of fMRI is critical for its clinical use. Clinical fMRI's challenges and potential solutions are discussed. Intraoperative use and validation of fMRI are discussed.
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Affiliation(s)
- Michael A Silva
- Harvard Medical School, Boston, MA, USA; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Alfred P See
- Harvard Medical School, Boston, MA, USA; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Walid I Essayed
- Harvard Medical School, Boston, MA, USA; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Alexandra J Golby
- Harvard Medical School, Boston, MA, USA; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Yanmei Tie
- Harvard Medical School, Boston, MA, USA; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA.
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16
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[Doping for the brain]. Z Gerontol Geriatr 2017; 51:143-148. [PMID: 29209802 DOI: 10.1007/s00391-017-1351-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/02/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022]
Abstract
The enhancement of physical and cognitive abilities (i. e. concentration, vigilance, memory) has always been desirable for humans. The term pharmacological neuroenhancement refers to the use of legal or nonprescription psychoactive substances by healthy subjects with the intention of cognitive enhancement. To give the most prominent example, caffeine serves worldwide as a natural stimulant. Brain doping, however, specifies the use of illegal substances or prescription drugs beyond approval with the purpose of cognitive enhancement. Only amphetamines, methylphenidate and modafinil have significant effects on attentiveness, concentration and alertness, whereas other substances, such as anti-dementia drugs or anti-depressants failed to demonstrate cognitive enhancement in healthy subjects.
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17
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Kahathuduwa CN, Dhanasekara CS, Chin SH, Davis T, Weerasinghe VS, Dassanayake TL, Binks M. l-Theanine and caffeine improve target-specific attention to visual stimuli by decreasing mind wandering: a human functional magnetic resonance imaging study. Nutr Res 2017; 49:67-78. [PMID: 29420994 DOI: 10.1016/j.nutres.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/31/2017] [Accepted: 11/12/2017] [Indexed: 11/17/2022]
Abstract
Oral intake of l-theanine and caffeine supplements is known to be associated with faster stimulus discrimination, possibly via improving attention to stimuli. We hypothesized that l-theanine and caffeine may be bringing about this beneficial effect by increasing attention-related neural resource allocation to target stimuli and decreasing deviation of neural resources to distractors. We used functional magnetic resonance imaging (fMRI) to test this hypothesis. Solutions of 200mg of l-theanine, 160mg of caffeine, their combination, or the vehicle (distilled water; placebo) were administered in a randomized 4-way crossover design to 9 healthy adult men. Sixty minutes after administration, a 20-minute fMRI scan was performed while the subjects performed a visual color stimulus discrimination task. l-Theanine and l-theanine-caffeine combination resulted in faster responses to targets compared with placebo (∆=27.8milliseconds, P=.018 and ∆=26.7milliseconds, P=.037, respectively). l-Theanine was associated with decreased fMRI responses to distractor stimuli in brain regions that regulate visual attention, suggesting that l-theanine may be decreasing neural resource allocation to process distractors, thus allowing to attend to targets more efficiently. l-Theanine-caffeine combination was associated with decreased fMRI responses to target stimuli as compared with distractors in several brain regions that typically show increased activation during mind wandering. Factorial analysis suggested that l-theanine and caffeine seem to have a synergistic action in decreasing mind wandering. Therefore, our hypothesis is that l-theanine and caffeine may be decreasing deviation of attention to distractors (including mind wandering); thus, enhancing attention to target stimuli was confirmed.
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Affiliation(s)
- Chanaka N Kahathuduwa
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA; Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA
| | - Chathurika S Dhanasekara
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Shao-Hua Chin
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Tyler Davis
- Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA; Department of Psychological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka
| | - Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; School of Psychology, The University of Newcastle, New South Wales, Australia
| | - Martin Binks
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.
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18
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Hahn B, Harvey AN, Gold JM, Ross TJ, Stein EA. Load-dependent hyperdeactivation of the default mode network in people with schizophrenia. Schizophr Res 2017; 185:190-196. [PMID: 28073606 PMCID: PMC6104387 DOI: 10.1016/j.schres.2017.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/28/2016] [Accepted: 01/01/2017] [Indexed: 02/01/2023]
Abstract
Schizophrenia is associated with impairment in a range of cognitive functions. Neuroimaging studies have reported lower, but also higher, task-induced activation accompanying impaired performance. Differences in task-load and the ability of people with schizophrenia (PSZ) to stay engaged in the cognitive operations probed appear to underlie such discrepancies. Similarly, task-induced deactivation of the default mode network (DMN) was weaker in PSZ relative to healthy control subjects (HCS) in most studies, but some reported greater deactivation. An inability to stay engaged in the cognitive operations could account for these discrepancies, too, as it would lead to more time off-task and consequently less deactivation of DMN functions. The present study employed a change detection paradigm with small to moderate set sizes (SSs) of 1, 2, and 4 items. Task training prior to fMRI scanning abolished the group difference in no-response trials. Task-positive regions of interest (ROIs) displayed greater activation with increasing SS in both groups. PSZ showed greater activation relative to HCS at SSs 1 and 2. DMN ROIs displayed greater deactivation with increasing SS in PSZ, but not in HCS, and PSZ tended to hyperdeactivate DMN regions at SS 4. No hypodeactivation was observed in PSZ. In conclusion, when minimizing differences in task-engagement, PSZ tend to over-recruit task-positive regions during low-load operations, and hyperdeactivate DMN functions at higher load, perhaps reflecting heightened non-specific vigilance or effort when dealing with cognitive challenges. This speaks against an inability to down-regulate task-independent thought processes as a primary mechanism underlying cognitive impairment in schizophrenia.
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Affiliation(s)
- Britta Hahn
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, USA.
| | - Alexander N Harvey
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, USA.
| | - James M Gold
- University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, USA.
| | - Thomas J Ross
- National Institute on Drug Abuse - Intramural Research Program, Neuroimaging Research Branch, 251 Bayview Blvd, Suite 200, Baltimore, MD 21224, USA.
| | - Elliot A Stein
- National Institute on Drug Abuse - Intramural Research Program, Neuroimaging Research Branch, 251 Bayview Blvd, Suite 200, Baltimore, MD 21224, USA.
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19
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Hosford PS, Millar J, Ramage AG, Marina N. Abnormal oxygen homeostasis in the nucleus tractus solitarii of the spontaneously hypertensive rat. Exp Physiol 2017; 102:389-396. [PMID: 28120502 PMCID: PMC5396378 DOI: 10.1113/ep086023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/19/2017] [Indexed: 01/08/2023]
Abstract
NEW FINDINGS What is the central question of this study? Arterial hypertension is associated with impaired neurovascular coupling in the somatosensory cortex. Abnormalities in activity-dependent oxygen consumption in brainstem regions involved in the control of cardiovascular reflexes have not been explored previously. What is the main finding and its importance? Using fast-cyclic voltammetry, we found that changes in local tissue PO2 in the nucleus tractus solitarii induced by electrical stimulation of the vagus nerve are significantly impaired in spontaneously hypertensive rats. This is consistent with previous observations showing that brainstem hypoxia plays an important role in the pathogenesis of arterial hypertension. The effects of arterial hypertension on cerebral blood flow remain poorly understood. Haemodynamic responses within the somatosensory cortex have been shown to be impaired in the spontaneously hypertensive rat (SHR) model. However, it is unknown whether arterial hypertension affects oxygen homeostasis in vital brainstem areas that control cardiovascular reflexes. In this study, we assessed vagus nerve stimulation-induced changes in local tissue PO2 (PtO2) in the caudal nucleus tractus solitarii (cNTS) of SHRs and normotensive Wistar rats. Measurements of PtO2 were performed using a novel application of fast-cyclic voltammetry, which allows higher temporal resolution of O2 changes than traditional optical fluorescence techniques. Electrical stimulation of the central cut end of the vagus nerve (ESVN) caused profound reductions in arterial blood pressure along with biphasic changes in PtO2 in the cNTS, characterized by a rapid decrease in PtO2 ('initial dip') followed by a post-stimulus overshoot above baseline. The initial dip was found to be significantly smaller in SHRs compared with normotensive Wistar rats even after ganglionic blockade. The post-ESVN overshoot was similar in both groups but was reduced in Wistar rats after ganglionic blockade. In conclusion, neural activity-dependent changes in tissue oxygen in brainstem cardiovascular autonomic centres are significantly impaired in animals with arterial hypertension.
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Affiliation(s)
- Patrick S Hosford
- Center for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Julian Millar
- Barts and the London School of Medicine and Dentistry, London, UK
| | - Andrew G Ramage
- Center for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Nephtali Marina
- Center for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Clinical Pharmacology and Experimental Therapeutics, Division of Medicine, University College London, London, UK
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20
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Buch S, Ye Y, Haacke EM. Quantifying the changes in oxygen extraction fraction and cerebral activity caused by caffeine and acetazolamide. J Cereb Blood Flow Metab 2017; 37:825-836. [PMID: 27029391 PMCID: PMC5363462 DOI: 10.1177/0271678x16641129] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A quantitative estimate of cerebral blood oxygen saturation is of critical importance in the investigation of cerebrovascular disease. We aimed to measure the change in venous oxygen saturation (Yv) before and after the intake of the vaso-dynamic agents caffeine and acetazolamide with high spatial resolution using susceptibility mapping. Caffeine and acetazolamide were administered on separate days to five healthy volunteers to measure the change in oxygen extraction fraction. The internal streaking artifacts in the susceptibility maps were reduced by giving an initial susceptibility value uniformly to the structure-of-interest, based on a priori information. Using this technique, Yv for normal physiological conditions, post-caffeine and post-acetazolamide was measured inside the internal cerebral veins as YNormal = 69.1 ± 3.3%, YCaffeine = 60.5 ± 2.8%, and YAcet = 79.1 ± 4.0%. This suggests that susceptibility mapping can serve as a sensitive biomarker for measuring reductions in cerebro-vascular reserve through abnormal vascular response. The percentage change in oxygen extraction fraction for caffeine and acetazolamide were found to be +27.0 ± 3.8% and -32.6 ± 2.1%, respectively. Similarly, the relative changes in cerebral blood flow in the presence of caffeine and acetazolamide were found to be -30.3% and + 31.5%, suggesting that the cerebral metabolic rate of oxygen remains stable between normal and challenged brain states for healthy subjects.
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Affiliation(s)
- Sagar Buch
- The MRI Institute for Biomedical Research, Waterloo, Canada
| | - Yongquan Ye
- Department of Radiology, Wayne State University, Detroit, USA
| | - E Mark Haacke
- The MRI Institute for Biomedical Research, Waterloo, Canada
- Department of Radiology, Wayne State University, Detroit, USA
- E. Mark Haacke, Radiology Department, Wayne State University, Detroit, Michigan 48201, USA.
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21
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Wang Y, Venton BJ. Correlation of transient adenosine release and oxygen changes in the caudate-putamen. J Neurochem 2016; 140:13-23. [PMID: 27314215 DOI: 10.1111/jnc.13705] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/19/2016] [Accepted: 06/10/2016] [Indexed: 12/01/2022]
Abstract
Adenosine is an endogenous nucleoside that modulates important physiological processes, such as vasodilation, in the central nervous system. A rapid, 2-4 s, mode of adenosine signaling has been recently discovered, but the relationship between this type of adenosine and blood flow change has not been characterized. In this study, adenosine and oxygen changes were simultaneously measured using fast-scan cyclic voltammetry. Oxygen changes occur when there is an increase in local cerebral blood flow and thus are a measure of vasodilation. About 34% of adenosine transients in the rat caudate-putamen are correlated with a subsequent transient change in oxygen. The amount of oxygen was correlated with the concentration of adenosine release and larger adenosine transients (over 0.4 μM) always had subsequent oxygen changes. The average duration of adenosine and oxygen transients was 3.2 and 3.5 s, respectively. On average, the adenosine release starts and peaks 0.2 s prior to the oxygen. The A2a antagonist, SCH442416, decreased the number of both adenosine and oxygen transient events by about 32%. However, the A1 antagonist, DPCPX, did not significantly affect simultaneous adenosine and oxygen release. The nitric oxide (NO) synthase inhibitor l-NAME also did not affect the concentration or number of adenosine and oxygen release events. These results demonstrate that both adenosine and oxygen release are modulated via A2a receptors. The correlation of transient concentrations, time delay between adenosine and oxygen peaks, and effect of A2a receptors suggests that adenosine modulates blood flow on a rapid, sub-second time scale. Read the Editorial Highlight for this article on page 10.
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Affiliation(s)
- Ying Wang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - B Jill Venton
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
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Soares JM, Magalhães R, Moreira PS, Sousa A, Ganz E, Sampaio A, Alves V, Marques P, Sousa N. A Hitchhiker's Guide to Functional Magnetic Resonance Imaging. Front Neurosci 2016; 10:515. [PMID: 27891073 PMCID: PMC5102908 DOI: 10.3389/fnins.2016.00515] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/25/2016] [Indexed: 12/12/2022] Open
Abstract
Functional Magnetic Resonance Imaging (fMRI) studies have become increasingly popular both with clinicians and researchers as they are capable of providing unique insights into brain functions. However, multiple technical considerations (ranging from specifics of paradigm design to imaging artifacts, complex protocol definition, and multitude of processing and methods of analysis, as well as intrinsic methodological limitations) must be considered and addressed in order to optimize fMRI analysis and to arrive at the most accurate and grounded interpretation of the data. In practice, the researcher/clinician must choose, from many available options, the most suitable software tool for each stage of the fMRI analysis pipeline. Herein we provide a straightforward guide designed to address, for each of the major stages, the techniques, and tools involved in the process. We have developed this guide both to help those new to the technique to overcome the most critical difficulties in its use, as well as to serve as a resource for the neuroimaging community.
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Affiliation(s)
- José M. Soares
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
| | - Ricardo Magalhães
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
| | - Pedro S. Moreira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
| | - Alexandre Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
- Department of Informatics, University of MinhoBraga, Portugal
| | - Edward Ganz
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
| | - Adriana Sampaio
- Neuropsychophysiology Lab, CIPsi, School of Psychology, University of MinhoBraga, Portugal
| | - Victor Alves
- Department of Informatics, University of MinhoBraga, Portugal
| | - Paulo Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of MinhoBraga, Portugal
- ICVS/3B's - PT Government Associate LaboratoryBraga, Portugal
- Clinical Academic Center – BragaBraga, Portugal
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Dubois J, Adolphs R. Building a Science of Individual Differences from fMRI. Trends Cogn Sci 2016; 20:425-443. [PMID: 27138646 DOI: 10.1016/j.tics.2016.03.014] [Citation(s) in RCA: 371] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 11/19/2022]
Abstract
To date, fMRI research has been concerned primarily with evincing generic principles of brain function through averaging data from multiple subjects. Given rapid developments in both hardware and analysis tools, the field is now poised to study fMRI-derived measures in individual subjects, and to relate these to psychological traits or genetic variations. We discuss issues of validity, reliability and statistical assessment that arise when the focus shifts to individual subjects and that are applicable also to other imaging modalities. We emphasize that individual assessment of neural function with fMRI presents specific challenges and necessitates careful consideration of anatomical and vascular between-subject variability as well as sources of within-subject variability.
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Affiliation(s)
- Julien Dubois
- Division of the Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Ralph Adolphs
- Division of the Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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Abstract
Psychedelics (serotonergic hallucinogens) are powerful psychoactive substances that alter perception and mood and affect numerous cognitive processes. They are generally considered physiologically safe and do not lead to dependence or addiction. Their origin predates written history, and they were employed by early cultures in many sociocultural and ritual contexts. After the virtually contemporaneous discovery of (5R,8R)-(+)-lysergic acid-N,N-diethylamide (LSD)-25 and the identification of serotonin in the brain, early research focused intensively on the possibility that LSD and other psychedelics had a serotonergic basis for their action. Today there is a consensus that psychedelics are agonists or partial agonists at brain serotonin 5-hydroxytryptamine 2A receptors, with particular importance on those expressed on apical dendrites of neocortical pyramidal cells in layer V. Several useful rodent models have been developed over the years to help unravel the neurochemical correlates of serotonin 5-hydroxytryptamine 2A receptor activation in the brain, and a variety of imaging techniques have been employed to identify key brain areas that are directly affected by psychedelics. Recent and exciting developments in the field have occurred in clinical research, where several double-blind placebo-controlled phase 2 studies of psilocybin-assisted psychotherapy in patients with cancer-related psychosocial distress have demonstrated unprecedented positive relief of anxiety and depression. Two small pilot studies of psilocybin-assisted psychotherapy also have shown positive benefit in treating both alcohol and nicotine addiction. Recently, blood oxygen level-dependent functional magnetic resonance imaging and magnetoencephalography have been employed for in vivo brain imaging in humans after administration of a psychedelic, and results indicate that intravenously administered psilocybin and LSD produce decreases in oscillatory power in areas of the brain's default mode network.
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Affiliation(s)
- David E Nichols
- Eschelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
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Chodkowski BA, Cowan RL, Niswender KD. Imbalance in Resting State Functional Connectivity is Associated with Eating Behaviors and Adiposity in Children. Heliyon 2016; 2:e00058. [PMID: 26878067 PMCID: PMC4750053 DOI: 10.1016/j.heliyon.2015.e00058] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 12/05/2022] Open
Abstract
Background and Hypothesis Over the past 30 years, childhood obesity in the US has nearly doubled, while obesity has tripled among adolescents. Non-homeostatic eating, influenced by impulsivity and inhibition, may undermine successful long-term weight loss. We hypothesized that unhealthy eating habits and adiposity among children are associated with functional connectivity between brain regions associated with impulsivity, response inhibition, and reward. Methods We analyzed resting state functional magnetic resonance images from 38 children, ages 8–13. Using seed-based resting state functional connectivity, we quantified connectivity between brain regions associated with response inhibition (inferior parietal lobe [IPL]), impulsivity (frontal pole), and reward (nucleus accumbens [NAc]). We assessed the relationship of resting state functional connectivity with adiposity, quantified by BMI z-score, and eating behaviors, as measured by the Child Eating Behaviour Questionnaire (CEBQ). We computed an imbalance measure—the difference between [frontal pole:NAC] and [ipl:nac] functional connectivity—and investigated the relationship of this imbalance with eating behaviors and adiposity. Results As functional connectivity imbalance is increasingly biased toward impulsivity, adiposity increases. Similarly, as impulsivity-biased imbalance increases, food approach behaviors increase and food avoidance behaviors decrease. Increased adiposity is associated with increased food approach behaviors and decreased food avoidance behaviors. Conclusions In the absence of any explicit eating-related stimuli, the developing brain is primed toward food approach and away from food avoidance behavior with increasing adiposity. Imbalance in resting state functional connectivity that is associated with non-homeostatic eating develops during childhood, as early as 8–13 years of age. Our results indicate the importance of identifying children at risk for obesity for earlier intervention. In addition to changing eating habits and physical activity, strategies that normalize neural functional connectivity imbalance are needed to maintain healthy weight. Mindfulness may be one such approach as it is associated with increased response inhibition and decreased impulsivity.
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Affiliation(s)
- BettyAnn A. Chodkowski
- Chemical and Physical Biology Program, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Ronald L. Cowan
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
| | - Kevin D. Niswender
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
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Krishnamurthy LC, Liu P, Ge Y, Lu H. Vessel-specific quantification of blood oxygenation with T2-relaxation-under-phase-contrast MRI. Magn Reson Med 2015; 71:978-89. [PMID: 23568830 DOI: 10.1002/mrm.24750] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurement of venous oxygenation (Yv) is a critical step toward quantitative assessment of brain oxygen metabolism, a key index in many brain disorders. The present study aims to develop a noninvasive, rapid, and reproducible method to measure Yv in a vessel-specific manner. THEORY The method, T2-Relaxation-Under-Phase-Contrast MRI, utilizes complex subtraction of phase-contrast to isolate pure blood signal, applies nonslice-selective T2-preparation to measure T2, and converts T2 to oxygenation using a calibration plot. METHODS Following feasibility demonstration, several technical aspects were examined, including validation with an established global Yv technique, test-retest reproducibility, sensitivity to detect oxygenation changes due to hypoxia and caffeine challenges, applicability of echo-planar-imaging (EPI) acquisition to shorten scan duration, and ability to study veins with a caliber of 1-2 mm. RESULTS T2-Relaxation-Under-Phase-Contrast was able to simultaneously measure Yv in all major veins in the brain, including sagittal sinus, straight sinus, great vein, and internal cerebral vein. T2-Relaxation-Under-Phase-Contrast results showed an excellent agreement with the reference technique, high sensitivity to oxygenation changes, and test-retest variability of 3.5 ± 1.0%. The use of segmented-EPI was able to reduce the scan duration to 1.5 minutes. It was also feasible to study pial veins and deep veins. CONCLUSION T2-Relaxation-Under-Phase-Contrast MRI is a promising technique for vessel-specific oxygenation measurement.
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Affiliation(s)
- Lisa C Krishnamurthy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Biomedical Engineering, University of Texas at Arlington, Arlington, Texas, USA
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Heilbronner U, Hinrichs H, Heinze HJ, Zaehle T. Caffeine differentially alters cortical hemodynamic activity during working memory: a near infrared spectroscopy study. BMC Res Notes 2015; 8:520. [PMID: 26427367 PMCID: PMC4590696 DOI: 10.1186/s13104-015-1491-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 09/21/2015] [Indexed: 11/10/2022] Open
Abstract
Background Caffeine is a widely used stimulant with potentially beneficial effects on cognition as well as vasoconstrictive properties. In functional magnetic imaging research, caffeine has gained attention as a potential enhancer of the blood oxygenation level-dependent (BOLD) response. In order to clarify changes of oxy- and deoxyhemoglobin (HbO and HbR) induced by caffeine during a cognitive task, we investigated a working memory (WM) paradigm (visual 2-back) using near-infrared spectroscopy (NIRS). Results Behaviorally, caffeine had no effect on the WM performance but influenced reaction times in the 0-back condition. NIRS data demonstrate caffeine-dependent alterations of the course of the hemodynamic response. The intake of 200 mg caffeine caused a significant decrease of the HbO response between 20 and 40 s after the onset of a 2-back task in the bilateral inferior frontal cortex (IFC). In parallel, the HbR response of the left IFC was significantly increased due to caffeine intake. Conclusions In line with previous results, we did not detect an effect of caffeine on most aspects of behavior. Effects of caffeine on brain vasculature were detected as general reduction of HbO. Neuronal effects of caffeine are reflected in an increased concentration of HbR in the left hemisphere when performing a verbal memory task and suggest influences on metabolism.
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Affiliation(s)
- Urs Heilbronner
- DZNE, German Center for Neurodegenerative Diseases, Otto-von-Guericke University, Magdeburg, Germany. .,Institute of Psychiatric Phenomics and Genomics, Ludwig-Maximilians-University, Munich, Germany.
| | - Hermann Hinrichs
- DZNE, German Center for Neurodegenerative Diseases, Otto-von-Guericke University, Magdeburg, Germany. .,LIN, Leibniz Institute for Neurobiology, Magdeburg, Germany. .,Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
| | - Hans-Jochen Heinze
- DZNE, German Center for Neurodegenerative Diseases, Otto-von-Guericke University, Magdeburg, Germany. .,LIN, Leibniz Institute for Neurobiology, Magdeburg, Germany. .,Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
| | - Tino Zaehle
- DZNE, German Center for Neurodegenerative Diseases, Otto-von-Guericke University, Magdeburg, Germany. .,LIN, Leibniz Institute for Neurobiology, Magdeburg, Germany. .,Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
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Bourke JH, Wall MB. phMRI: methodological considerations for mitigating potential confounding factors. Front Neurosci 2015; 9:167. [PMID: 25999812 PMCID: PMC4423340 DOI: 10.3389/fnins.2015.00167] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/23/2015] [Indexed: 11/16/2022] Open
Abstract
Pharmacological Magnetic Resonance Imaging (phMRI) is a variant of conventional MRI that adds pharmacological manipulations in order to study the effects of drugs, or uses pharmacological probes to investigate basic or applied (e.g., clinical) neuroscience questions. Issues that may confound the interpretation of results from various types of phMRI studies are briefly discussed, and a set of methodological strategies that can mitigate these problems are described. These include strategies that can be employed at every stage of investigation, from study design to interpretation of resulting data, and additional techniques suited for use with clinical populations are also featured. Pharmacological MRI is a challenging area of research that has both significant advantages and formidable difficulties, however with due consideration and use of these strategies many of the key obstacles can be overcome.
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Affiliation(s)
- Julius H Bourke
- Centre for Psychiatry, The London School of Medicine and Dentistry, Wolfson Barts Institute for Preventive Medicine, Queen Mary University of London London, UK
| | - Matthew B Wall
- Imanova Centre for Imaging Sciences, Imperial College London, Hammersmith Hospital London, UK ; Division of Brain Sciences, Imperial College London London, UK
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Krishnamurthy LC, Mao D, King KS, Lu H. Correction and optimization of a T2-based approach to map blood oxygenation in small cerebral veins. Magn Reson Med 2015; 75:1100-9. [PMID: 25846113 DOI: 10.1002/mrm.25686] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/28/2015] [Accepted: 02/17/2015] [Indexed: 12/11/2022]
Abstract
PURPOSE Cerebral venous blood oxygenation (Yv ) is an important biomarker in brain physiology and function. The present study proposes a procedure to provide a quantitative map of the brain's intravascular Yv. THEORY AND METHODS The method is based on a pulse sequence, T2 -Relaxation-Under-Phase-Contrast (TRU-PC) MRI, with postprocessing approaches to correct eddy-current effects. A complete scan protocol consists of four TRU-PC scans sensitized to large and small vessels with anterior-posterior and foot-head flow-encoding directions, and the data are analyzed conjunctively. Eddy-current correction was performed by fitting the tissue phase to a hyperplane, and then subtracting the eddy-current phase from the measured vessel phase. The reproducibility of the Yv-maps was examined in five participants. Sensitivity of the Yv map to a caffeine challenge was studied in another five participants. RESULTS Removal of eddy-current induced artifact allowed for the correction of T2 measurements, as demonstrated in vivo and with simulation. A Yv-map depicting all vessels in the slice can be obtained with the proposed protocol. Test-retest variability of the Yv -map was 3.7 ± 1.2%. Yv reduction can be reliably detected (P < 0.001) following the caffeine ingestion. CONCLUSION With the proposed TRU-PC protocol and eddy-current correction procedure, an accurate, vessel-specific Yv map of the human brain can be obtained.
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Affiliation(s)
- Lisa C Krishnamurthy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biomedical Engineering, University of Texas at Arlington, Arlington, Texas, USA
| | - Deng Mao
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kevin S King
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hanzhang Lu
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
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Kohn N, Toygar T, Weidenfeld C, Berthold-Losleben M, Chechko N, Orfanos S, Vocke S, Durst A, Laoutidis ZG, Karges W, Schneider F, Habel U. In a sweet mood? Effects of experimental modulation of blood glucose levels on mood-induction during fMRI. Neuroimage 2015; 113:246-56. [PMID: 25795339 DOI: 10.1016/j.neuroimage.2015.03.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 01/21/2023] Open
Abstract
Glucose is the primary source of energy for the human brain. Previous literature has shown that varying blood glucose levels may have a strong impact on behaviour, subjective mood, and the intensity of the BOLD signal measured in fMRI. Therefore, blood glucose levels varying even within the normal range may interact with cognitive and emotional processing as well as BOLD signal. Here, in a placebo-controlled, double-blind crossover study on 20 healthy women, we show that overnight fasting, compared to an elevated glucose condition, influences brain activation and the affective state during mood induction. Results indicate that our brain may compensate for low glucose levels during fasting by stronger recruitment of the brain areas relevant to the task at hand. Additionally, we systematically tested the effect of prior cognitive effort on behavioural and neural patterns and found that elevated activation is only associated with maintained performance as long as no prior cognitively challenging task is administered. Prior cognitive effort leads to deteriorated performance and a further increase in emotion-associated brain activation in the pregenual anterior and posterior cingulate, the superior frontal gyrus, and the pre-SMA. These results are in line with the strength model of self-regulation. Our results corroborate the strength model of self-regulation and extend it to affect regulation processes. Additionally, our observations suggest that experimentally controlling for fasting state or glucose levels may be beneficial, especially when studying processes that involve self-regulation.
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Affiliation(s)
- N Kohn
- Institute of Neuroscience and Medicine (INM-6), Jülich Research Centre, Jülich, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany.
| | - T Toygar
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; Department of Biology, RWTH Aachen University, 52074 Aachen, Germany
| | - C Weidenfeld
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - M Berthold-Losleben
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - N Chechko
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - S Orfanos
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - S Vocke
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - A Durst
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - Z G Laoutidis
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; Department of Psychiatry and Psychotherapy, University of Düsseldorf, Bergische Landstrasse 2, 40629 Düsseldorf, Germany
| | - W Karges
- Division of Endocrinology and Diabetes, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany
| | - F Schneider
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
| | - U Habel
- Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen, 52074 Aachen, Germany; JARA Brain - Translational Brain Medicine, Jülich-Aachen, Germany
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Reproducibility of pharmacological ASL using sequences from different vendors: implications for multicenter drug studies. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2015; 28:427-36. [PMID: 25588906 DOI: 10.1007/s10334-014-0480-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/30/2014] [Accepted: 12/24/2014] [Indexed: 01/08/2023]
Abstract
OBJECT The current study assesses the multicenter feasibility of pharmacological arterial spin labeling (ASL) by comparing a caffeine-induced relative cerebral blood flow decrease (%CBF↓) measured with two pseudo-continuous ASL sequences as provided by two major vendors. MATERIALS AND METHODS Twenty-two healthy volunteers were scanned twice with both a 3D spiral (GE) and a 2D EPI (Philips) sequence. The inter-session reproducibility was evaluated by comparisons of the mean and within-subject coefficient of variability (wsCV) of the %CBF↓, both for the total cerebral gray matter and on a voxel level. RESULTS The %CBF↓ was larger when measured with the 3D spiral sequence (23.9 ± 5.9 %) than when measured with the 2D EPI sequence (19.2 ± 5.6 %) on a total gray matter level (p = 0.02), and on a voxel level in the posterior watershed area (p < 0.001). There was no difference between the gray matter wsCV of the 3D spiral (57.3 %) and 2D EPI sequence (66.7 %, p = 0.3), whereas on a voxel level, the wsCV was visibly different between the sequences. CONCLUSION The observed differences between ASL sequences of both vendors can be explained by differences in the employed readout modules. These differences may seriously hamper multicenter pharmacological ASL, which strongly encourages standardization of ASL implementations.
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Dodd FL, Kennedy DO, Riby LM, Haskell-Ramsay CF. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology (Berl) 2015; 232:2563-76. [PMID: 25761837 PMCID: PMC4480845 DOI: 10.1007/s00213-015-3895-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 02/11/2015] [Indexed: 01/09/2023]
Abstract
RATIONALE Evidence suggests interactive effects of the tea components caffeine and L-theanine on behaviour, yet no data exists exploring the impact of the two on cerebral blood flow (CBF). OBJECTIVES The current placebo-controlled, double-blind, counterbalanced, crossover study examined the effects of caffeine and L-theanine on CBF and extended previous cognitive and mood findings by using lower doses than previous studies of a similar methodology, which more closely reflect the ratios present in tea. METHODS Twelve habitual consumers and 12 non-habitual consumers of caffeine each received 75 mg caffeine, 50 mg L-theanine, 75 mg caffeine plus 50 mg L-theanine, and placebo in a counterbalanced order across four separate visits. CBF was measured via near-infrared spectroscopy with cognition and mood assessed at baseline and 30 min post-dose. Salivary caffeine and peripheral haemodynamics were co-monitored. RESULTS Caffeine reduced oxygenated haemoglobin (oxy-Hb), increased deoxygenated haemoglobin (deoxy-Hb), improved performance on attention tasks and increased overall mood ratings. Increases in deoxy-Hb following caffeine were more pronounced in non-consumers. Some evidence for increased deoxy-Hb remained when caffeine was combined with L-theanine, but this effect was attenuated and the effects of caffeine on oxy-Hb, cognition and mood were eradicated. CONCLUSIONS Combining L-theanine with caffeine, at levels and ratios equivalent to one to two cups of tea, eliminated the vasoconstrictive effect and behavioural effects of caffeine. This supports previous findings of an interaction between these substances, despite a lack of effects of L-theanine in isolation. However, at the levels tested here, this did not lead to a positive impact on behaviour.
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Affiliation(s)
- F. L. Dodd
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - D. O. Kennedy
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - L. M. Riby
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - C. F. Haskell-Ramsay
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
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Martin C. Contributions and complexities from the use of in vivo animal models to improve understanding of human neuroimaging signals. Front Neurosci 2014; 8:211. [PMID: 25191214 PMCID: PMC4137227 DOI: 10.3389/fnins.2014.00211] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 07/01/2014] [Indexed: 01/18/2023] Open
Abstract
Many of the major advances in our understanding of how functional brain imaging signals relate to neuronal activity over the previous two decades have arisen from physiological research studies involving experimental animal models. This approach has been successful partly because it provides opportunities to measure both the hemodynamic changes that underpin many human functional brain imaging techniques and the neuronal activity about which we wish to make inferences. Although research into the coupling of neuronal and hemodynamic responses using animal models has provided a general validation of the correspondence of neuroimaging signals to specific types of neuronal activity, it is also highlighting the key complexities and uncertainties in estimating neural signals from hemodynamic markers. This review will detail how research in animal models is contributing to our rapidly evolving understanding of what human neuroimaging techniques tell us about neuronal activity. It will highlight emerging issues in the interpretation of neuroimaging data that arise from in vivo research studies, for example spatial and temporal constraints to neuroimaging signal interpretation, or the effects of disease and modulatory neurotransmitters upon neurovascular coupling. We will also give critical consideration to the limitations and possible complexities of translating data acquired in the typical animals models used in this area to the arena of human fMRI. These include the commonplace use of anesthesia in animal research studies and the fact that many neuropsychological questions that are being actively explored in humans have limited homologs within current animal models for neuroimaging research. Finally we will highlighting approaches, both in experimental animals models (e.g. imaging in conscious, behaving animals) and human studies (e.g. combined fMRI-EEG), that mitigate against these challenges.
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Affiliation(s)
- Chris Martin
- Department of Psychology, The University of Sheffield Sheffield, UK
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Breedlove KM, Breedlove EL, Robinson M, Poole VN, King JR, Rosenberger P, Rasmussen M, Talavage TM, Leverenz LJ, Nauman EA. Detecting Neurocognitive and Neurophysiological Changes as a Result of Subconcussive Blows Among High School Football Athletes. ACTA ACUST UNITED AC 2014. [DOI: 10.3928/19425864-20140507-02] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Wu WC, Lien SH, Chang JH, Yang SC. Caffeine alters resting-state functional connectivity measured by blood oxygenation level-dependent MRI. NMR IN BIOMEDICINE 2014; 27:444-52. [PMID: 24478235 PMCID: PMC4260672 DOI: 10.1002/nbm.3080] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/26/2013] [Accepted: 01/02/2014] [Indexed: 06/03/2023]
Abstract
This study aimed to investigate the pharmacological effect of caffeine on functional connectivity measured by resting-state blood oxygenation level-dependent (BOLD) MRI in the motor cortex, visual cortex and default mode network (DMN). The protocols and procedures of the study were reviewed and approved by the Institutional Review Board of our institution. On a 3-T clinical MR system, 20 healthy volunteers underwent imaging before and after oral ingestion of a 200-mg over-the-counter caffeine pill (data from three individuals were excluded from further analysis because of excessive motion). The demographics of the remaining participants were as follows: female/male, 8/9; age, 21-35 years; non-habitual caffeine consumers over the past 6 months. Functional connectivity was calculated using the general linear model, assessed in terms of connected area (voxels) and statistical significance (Student t-values), and correlated with changes in regional cerebral blood flow as measured by arterial spin labeling MRI. Per-subject data analysis showed that caffeine decreased functional connectivity in the motor/visual cortices, but its effects on DMN varied among subjects. Correlation analysis of the changes in functional connectivity and regional blood flow suggested that the effect of caffeine on BOLD functional connectivity was predominantly neural (motor/visual cortices) and partly vascular (DMN). Group analysis showed that, after caffeine ingestion, DMN involved more attentional networks, and more extrastriate areas were integrated into the functional connectivity of the visual cortex, which may be associated with the known pharmacological effect of caffeine in elevating alertness. Caffeine consumption should thus be considered in the experimental design and data interpretation of functional connectivity studies using resting-state BOLD MRI.
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Affiliation(s)
- Wen-Chau Wu
- Graduate Institute of Oncology, National Taiwan UniversityTaipei, Taiwan
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan UniversityTaipei, Taiwan
- Graduate Institute of Clinical Medicine, National Taiwan UniversityTaipei, Taiwan
- Department of Medical Imaging, National Taiwan University HospitalTaipei, Taiwan
| | - Shu-Hua Lien
- Department of Medical Imaging, National Taiwan University HospitalTaipei, Taiwan
| | - Jia-Horng Chang
- Department of Medical Imaging, National Taiwan University HospitalTaipei, Taiwan
| | - Shun-Chung Yang
- Department of Medical Imaging, National Taiwan University HospitalTaipei, Taiwan
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Viviani R, Lehmann ML, Stingl JC. Use of magnetic resonance imaging in pharmacogenomics. Br J Clin Pharmacol 2014; 77:684-94. [PMID: 23802603 PMCID: PMC3971984 DOI: 10.1111/bcp.12197] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 06/18/2013] [Indexed: 01/11/2023] Open
Abstract
Because of the large variation in the response to psychoactive medication, many studies have attempted to uncover genetic factors that determine response. While considerable knowledge exists on the large effects of genetic polymorphisms on pharmacokinetics and plasma concentrations of drugs, effects of the concentration at the target site and pharmacodynamic effects on brain functions in disease are much less known. This article reviews the role of magnetic resonance imaging (MRI) to visualize response to medication in brain behaviour circuits in vivo in humans and assess the influence of pharmacogenetic factors. Two types of studies have been used to characterize effects of medication and genetic variation. In task-related activation studies the focus is on changes in the activity of a neural circuit associated with a specific psychological process. The second type of study investigates resting state perfusion. These studies provide an assessment of vascular changes associated with bioavailability of drugs in the brain, but may also assess changes in neural activity after binding of centrally active agents. Task-related pharmacogenetic studies of cognitive function have characterized the effects in the prefrontal cortex of genetic polymorphisms of dopamine receptors (DRD2), metabolic enzymes (COMT) and in the post-synaptic signalling cascade under the administration of dopamine agonists and antagonists. In contrast, pharmacogenetic imaging with resting state perfusion is still in its infancy. However, the quantitative nature of perfusion imaging, its non-invasive character and its repeatability might be crucial assets in visualizing the effects of medication in vivo in man during therapy.
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Affiliation(s)
- Roberto Viviani
- Department of Psychiatry and Psychotherapy III, University of Ulm, Ulm, Germany; Institute of Psychology, University of Innsbruck, Innsbruck, Austria
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Park CA, Kang CK, Son YD, Choi EJ, Kim SH, Oh ST, Kim YB, Park CW, Cho ZH. The effects of caffeine ingestion on cortical areas: functional imaging study. Magn Reson Imaging 2014; 32:366-71. [PMID: 24512799 DOI: 10.1016/j.mri.2013.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/01/2013] [Accepted: 12/25/2013] [Indexed: 12/11/2022]
Abstract
The effect of caffeine as a cognitive enhancer is well known; however, caffeine-induced changes in the cortical regions are still not very clear. Therefore, in this study, we conducted an investigation of the activation and deactivation with blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) and of metabolic activity change with positron emission tomography (PET) in the human brain. Fourteen healthy subjects performed a visuomotor task inducing attention with 3T MRI, and PET imaging was also carried out in seven subjects to determine the cerebral glucose metabolic changes of caffeine at rest. The result by fMRI showed increased BOLD activation in the left cerebellum, putamen, insula, thalamus and the right primary motor cortex, and decreased BOLD deactivation in the posterior medial and the left posterior lateral cortex. Also, the resting state PET data showed reduced metabolic activity in the putamen, caudate nucleus, insula, pallidum and posterior medial cortex. The common cortical regions between fMRI and PET, such as putamen, insula and posterior medial cortex, where significant changes occurred after caffeine ingestion, are well known to play an important role in cognitive function like attention. This result suggests that the effect of caffeine as a cognitive enhancer is derived by modulating the attentional areas.
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Affiliation(s)
- Chan-A Park
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Chang-Ki Kang
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Young-Don Son
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Eun-Jung Choi
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Sang-Hoon Kim
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Seung-Taek Oh
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Young-Bo Kim
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Chan-Woong Park
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea; Department of Pharmacology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Zang-Hee Cho
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea; Department of Radiological Sciences, University of California Irvine, CA 92697, USA.
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Williams RJ, McMahon KL, Hocking J, Reutens DC. Comparison of block and event-related experimental designs in diffusion-weighted functional MRI. J Magn Reson Imaging 2013; 40:367-75. [PMID: 24923816 DOI: 10.1002/jmri.24353] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 07/31/2013] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To compare diffusion-weighted functional magnetic resonance imaging (DfMRI), a novel alternative to the blood oxygenation level-dependent (BOLD) contrast, in a functional MRI experiment. MATERIALS AND METHODS Nine participants viewed contrast reversing (7.5 Hz) black-and-white checkerboard stimuli using block and event-related paradigms. DfMRI (b = 1800 mm/s(2)) and BOLD sequences were acquired. Four parameters describing the observed signal were assessed: percent signal change, spatial extent of the activation, the Euclidean distance between peak voxel locations, and the time-to-peak of the best fitting impulse response for different paradigms and sequences. RESULTS The BOLD conditions showed a higher percent signal change relative to DfMRI; however, event-related DfMRI showed the strongest group activation (t = 21.23, P < 0.0005). Activation was more diffuse and spatially closer to the BOLD response for DfMRI when the block design was used. DfMRIevent showed the shortest TTP (4.4 ± 0.88 sec). CONCLUSION The hemodynamic contribution to DfMRI may increase with the use of block designs.
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Affiliation(s)
- Rebecca J Williams
- University of Queensland, Centre for Advanced Imaging, Brisbane, Australia; University of Queensland, Queensland Brain Institute, Brisbane, Australia
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39
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Krainik A, Villien M, Troprès I, Attyé A, Lamalle L, Bouvier J, Pietras J, Grand S, Le Bas JF, Warnking J. Functional imaging of cerebral perfusion. Diagn Interv Imaging 2013; 94:1259-78. [PMID: 24011870 DOI: 10.1016/j.diii.2013.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.
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Affiliation(s)
- A Krainik
- Clinique universitaire de neuroradiologie et IRM, CHU de Grenoble, CS 10217, 38043 Grenoble cedex, France; Inserm U836, université Joseph-Fourier, site santé, chemin Fortuné-Ferrini, 38706 La Tronche cedex, France; UMS IRMaGe, unité IRM 3T recherche, CHU de Grenoble, CS 10217, 38043 Grenoble cedex 9, France.
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Blockley NP, Griffeth VEM, Simon AB, Buxton RB. A review of calibrated blood oxygenation level-dependent (BOLD) methods for the measurement of task-induced changes in brain oxygen metabolism. NMR IN BIOMEDICINE 2013; 26:987-1003. [PMID: 22945365 PMCID: PMC3639302 DOI: 10.1002/nbm.2847] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 07/17/2012] [Accepted: 08/02/2012] [Indexed: 05/23/2023]
Abstract
The dynamics of the blood oxygenation level-dependent (BOLD) response are dependent on changes in cerebral blood flow, cerebral blood volume and the cerebral metabolic rate of oxygen consumption. Furthermore, the amplitude of the response is dependent on the baseline physiological state, defined by the haematocrit, oxygen extraction fraction and cerebral blood volume. As a result of this complex dependence, the accurate interpretation of BOLD data and robust intersubject comparisons when the baseline physiology is varied are difficult. The calibrated BOLD technique was developed to address these issues. However, the methodology is complex and its full promise has not yet been realised. In this review, the theoretical underpinnings of calibrated BOLD, and issues regarding this theory that are still to be resolved, are discussed. Important aspects of practical implementation are reviewed and reported applications of this methodology are presented.
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Affiliation(s)
- Nicholas P Blockley
- Center for Functional Magnetic Resonance Imaging, Department of Radiology, University of California San Diego, La Jolla, CA, USA.
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42
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Wong CW, Olafsson V, Tal O, Liu TT. The amplitude of the resting-state fMRI global signal is related to EEG vigilance measures. Neuroimage 2013; 83:983-90. [PMID: 23899724 DOI: 10.1016/j.neuroimage.2013.07.057] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 06/18/2013] [Accepted: 07/20/2013] [Indexed: 10/26/2022] Open
Abstract
In resting-state functional magnetic resonance imaging (fMRI), functional connectivity measures can be influenced by the presence of a strong global component. A widely used pre-processing method for reducing the contribution of this component is global signal regression, in which a global mean time series signal is projected out of the fMRI time series data prior to the computation of connectivity measures. However, the use of global signal regression is controversial because the method can bias the correlation values to have an approximately zero mean and may in some instances create artifactual negative correlations. In addition, while many studies treat the global signal as a non-neural confound that needs to be removed, evidence from electrophysiological and fMRI measures in primates suggests that the global signal may contain significant neural correlates. In this study, we used simultaneously acquired fMRI and electroencephalographic (EEG) measures of resting-state activity to assess the relation between the fMRI global signal and EEG measures of vigilance in humans. We found that the amplitude of the global signal (defined as the standard deviation of the global signal) exhibited a significant negative correlation with EEG vigilance across subjects studied in the eyes-closed condition. In addition, increases in EEG vigilance due to the ingestion of caffeine were significantly associated with both a decrease in global signal amplitude and an increase in the average level of anti-correlation between the default mode network and the task-positive network.
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Affiliation(s)
- Chi Wah Wong
- Center for Functional Magnetic Resonance Imaging, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA 92093-0677, USA; Department of Radiology, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA 92093-0677, USA.
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43
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Haller S, Rodriguez C, Moser D, Toma S, Hofmeister J, Sinanaj I, Van De Ville D, Giannakopoulos P, Lovblad KO. Acute caffeine administration impact on working memory-related brain activation and functional connectivity in the elderly: a BOLD and perfusion MRI study. Neuroscience 2013; 250:364-71. [PMID: 23876323 DOI: 10.1016/j.neuroscience.2013.07.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 11/17/2022]
Abstract
In young individuals, caffeine-mediated blockade of adenosine receptors and vasoconstriction has direct repercussions on task-related activations, changes in functional connectivity, as well as global vascular effects. To date, no study has explored the effect of caffeine on brain activation patterns during highly demanding cognitive tasks in the elderly. This prospective, placebo-controlled crossover design comprises 24 healthy elderly individuals (mean age 68.8 ± 4.0 years, 17 females) performing a 2-back working memory (WM) task in functional magnetic resonance imaging (fMRI). Analyses include complimentary assessment of task-related activations (general linear model, GLM), functional connectivity (tensorial independent component analysis, TICA), and baseline perfusion (arterial spin labeling). Despite a reduction in whole-brain global perfusion (-22.7%), caffeine-enhanced task-related GLM activation in a local and distributed network is most pronounced in the bilateral striatum and to a lesser degree in the right middle and inferior frontal gyrus, bilateral insula, left superior and inferior parietal lobule as well as in the cerebellum bilaterally. TICA was significantly enhanced (+8.2%) in caffeine versus placebo in a distributed and task-relevant network including the pre-frontal cortex, the supplementary motor area, the ventral premotor cortex and the parietal cortex as well as the occipital cortex (visual stimuli) and basal ganglia. The inverse comparison of placebo versus caffeine had no significant difference. Activation strength of the task-relevant-network component correlated with response accuracy for caffeine yet not for placebo, indicating a selective cognitive effect of caffeine. The present findings suggest that acute caffeine intake enhances WM-related brain activation as well as functional connectivity of blood oxygen level-dependent fMRI in elderly individuals.
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Affiliation(s)
- S Haller
- Department of Imaging and Medical Informatics, University Hospitals of Geneva and Faculty of Medicine of the University of Geneva, Switzerland.
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44
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Liu TT. Neurovascular factors in resting-state functional MRI. Neuroimage 2013; 80:339-48. [PMID: 23644003 DOI: 10.1016/j.neuroimage.2013.04.071] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 04/12/2013] [Accepted: 04/16/2013] [Indexed: 11/16/2022] Open
Abstract
There has been growing interest in the use of resting-state functional magnetic resonance imaging (rsfMRI) for the assessment of disease and treatment, and a number of studies have reported significant disease-related changes in resting-state blood oxygenation level dependent (BOLD) signal amplitude and functional connectivity. rsfMRI is particularly suitable for clinical applications because the approach does not require the patient to perform a task and scans can be obtained in a relatively short amount of time. However, the mechanisms underlying resting-state BOLD activity are not well understood and thus the interpretation of changes in resting state activity is not always straightforward. The BOLD signal represents the hemodynamic response to neural activity, and changes in resting-state activity can reflect a complex combination of neural, vascular, and metabolic factors. This paper examines the role of neurovascular factors in rsfMRI and reviews approaches for the interpretation and analysis of resting state measures in the presence of confounding factors.
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Affiliation(s)
- Thomas T Liu
- Center for Functional Magnetic Resonance Imaging, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA 92093-0677, USA.
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45
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Can age-related CNS taste differences be detected as early as middle age? Evidence from fMRI. Neuroscience 2012; 232:194-203. [PMID: 23211563 DOI: 10.1016/j.neuroscience.2012.11.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 11/05/2012] [Accepted: 11/06/2012] [Indexed: 12/20/2022]
Abstract
Middle-aged Americans have higher obesity rates than any other age group, yet little is known about age-related changes in central taste function during this critical time. Research on taste and aging has primarily focused on psychophysical responses, and on older adults. Central taste processing in middle-age has not been investigated. In the current study, we compared functional magnetic resonance imaging (fMRI) activation of young and middle-aged adults during hedonic evaluation of a sweet and a bitter taste. A 2 (age group) by 2 (tastant) analysis of variance (ANOVA) on fMRI activation revealed: (1) a main effect of age (young adults>middle-aged adults) in the bilateral anterior cingulate, lentiform nucleus, putamen, caudate, and right precentral gyrus; (2) a main effect of taste (sweet>bitter) in the bilateral pre- and postcentral gyri, anterior cingulate and right middle frontal gyrus; qualified by (3) an age-by-taste interaction. Further inspection of the age-by-taste interaction revealed that there was a significant effect of age (greater activation in young adults) in sensory (insula) and reward (lentiform nucleus) regions during hedonic evaluation of the sweet taste; however, there was no age effect in the bitter taste condition. Further, young adults had greater responses during hedonic evaluation of sucrose than of caffeine in several sensory and motor processing regions (pre- and postcentral gyri, insula), but there were no taste-related differences in activation in the middle-aged adults. We speculate that these results might reflect early age-related differences in central taste processing that occur prior to deficits in gustatory function observed in old age, and this might have important implications for weight changes that occur during middle-age.
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Diukova A, Ware J, Smith JE, Evans CJ, Murphy K, Rogers PJ, Wise RG. Separating neural and vascular effects of caffeine using simultaneous EEG-FMRI: differential effects of caffeine on cognitive and sensorimotor brain responses. Neuroimage 2012; 62:239-49. [PMID: 22561357 PMCID: PMC3778750 DOI: 10.1016/j.neuroimage.2012.04.041] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 04/16/2012] [Accepted: 04/21/2012] [Indexed: 11/27/2022] Open
Abstract
The effects of caffeine are mediated through its non-selective antagonistic effects on adenosine A(1) and A(2A) adenosine receptors resulting in increased neuronal activity but also vasoconstriction in the brain. Caffeine, therefore, can modify BOLD FMRI signal responses through both its neural and its vascular effects depending on receptor distributions in different brain regions. In this study we aim to distinguish neural and vascular influences of a single dose of caffeine in measurements of task-related brain activity using simultaneous EEG-FMRI. We chose to compare low-level visual and motor (paced finger tapping) tasks with a cognitive (auditory oddball) task, with the expectation that caffeine would differentially affect brain responses in relation to these tasks. To avoid the influence of chronic caffeine intake, we examined the effect of 250 mg of oral caffeine on 14 non and infrequent caffeine consumers in a double-blind placebo-controlled cross-over study. Our results show that the task-related BOLD signal change in visual and primary motor cortex was significantly reduced by caffeine, while the amplitude and latency of visual evoked potentials over occipital cortex remained unaltered. However, during the auditory oddball task (target versus non-target stimuli) caffeine significantly increased the BOLD signal in frontal cortex. Correspondingly, there was also a significant effect of caffeine in reducing the target evoked response potential (P300) latency in the oddball task and this was associated with a positive potential over frontal cortex. Behavioural data showed that caffeine also improved performance in the oddball task with a significantly reduced number of missed responses. Our results are consistent with earlier studies demonstrating altered flow-metabolism coupling after caffeine administration in the context of our observation of a generalised caffeine-induced reduction in cerebral blood flow demonstrated by arterial spin labelling (19% reduction over grey matter). We were able to identify vascular effects and hence altered neurovascular coupling through the alteration of low-level task FMRI responses in the face of a preserved visual evoked potential. However, our data also suggest a cognitive effect of caffeine through its positive effect on the frontal BOLD signal consistent with the shortening of oddball EEG response latency. The combined use of EEG-FMRI is a promising methodology for investigating alterations in brain function in drug and disease studies where neurovascular coupling may be altered on a regional basis.
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Affiliation(s)
- Ana Diukova
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Jennifer Ware
- Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, UK
| | - Jessica E. Smith
- Department of Experimental Psychology, University of Bristol, Bristol, UK
| | - C. John Evans
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Kevin Murphy
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
| | - Peter J. Rogers
- Department of Experimental Psychology, University of Bristol, Bristol, UK
| | - Richard G. Wise
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK
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Kim SG, Ogawa S. Biophysical and physiological origins of blood oxygenation level-dependent fMRI signals. J Cereb Blood Flow Metab 2012; 32:1188-206. [PMID: 22395207 PMCID: PMC3390806 DOI: 10.1038/jcbfm.2012.23] [Citation(s) in RCA: 352] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
After its discovery in 1990, blood oxygenation level-dependent (BOLD) contrast in functional magnetic resonance imaging (fMRI) has been widely used to map brain activation in humans and animals. Since fMRI relies on signal changes induced by neural activity, its signal source can be complex and is also dependent on imaging parameters and techniques. In this review, we identify and describe the origins of BOLD fMRI signals, including the topics of (1) effects of spin density, volume fraction, inflow, perfusion, and susceptibility as potential contributors to BOLD fMRI, (2) intravascular and extravascular contributions to conventional gradient-echo and spin-echo BOLD fMRI, (3) spatial specificity of hemodynamic-based fMRI related to vascular architecture and intrinsic hemodynamic responses, (4) BOLD signal contributions from functional changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and cerebral metabolic rate of O(2) utilization (CMRO(2)), (5) dynamic responses of BOLD, CBF, CMRO(2), and arterial and venous CBV, (6) potential sources of initial BOLD dips, poststimulus BOLD undershoots, and prolonged negative BOLD fMRI signals, (7) dependence of stimulus-evoked BOLD signals on baseline physiology, and (8) basis of resting-state BOLD fluctuations. These discussions are highly relevant to interpreting BOLD fMRI signals as physiological means.
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Affiliation(s)
- Seong-Gi Kim
- Departments of Radiology, Neurobiology and Bioengineering, Neuroimaging Laboratory, University of Pittsburgh, Pittsburgh, PA, USA.
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48
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Wong CW, Olafsson V, Tal O, Liu TT. Anti-correlated networks, global signal regression, and the effects of caffeine in resting-state functional MRI. Neuroimage 2012; 63:356-64. [PMID: 22743194 DOI: 10.1016/j.neuroimage.2012.06.035] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 10/28/2022] Open
Abstract
Resting-state functional connectivity magnetic resonance imaging is proving to be an essential tool for the characterization of functional networks in the brain. Two of the major networks that have been identified are the default mode network (DMN) and the task positive network (TPN). Although prior work indicates that these two networks are anti-correlated, the findings are controversial because the anti-correlations are often found only after the application of a pre-processing step, known as global signal regression, that can produce artifactual anti-correlations. In this paper, we show that, for subjects studied in an eyes-closed rest state, caffeine can significantly enhance the detection of anti-correlations between the DMN and TPN without the need for global signal regression. In line with these findings, we find that caffeine also leads to widespread decreases in connectivity and global signal amplitude. Using a recently introduced geometric model of global signal effects, we demonstrate that these decreases are consistent with the removal of an additive global signal confound. In contrast to the effects observed in the eyes-closed rest state, caffeine did not lead to significant changes in global functional connectivity in the eyes-open rest state.
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Affiliation(s)
- Chi Wah Wong
- Center for Functional Magnetic Resonance Imaging, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA 92093-0677, USA.
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Klaassen EB, de Groot RHM, Evers EAT, Snel J, Veerman ECI, Ligtenberg AJM, Jolles J, Veltman DJ. The effect of caffeine on working memory load-related brain activation in middle-aged males. Neuropharmacology 2012; 64:160-7. [PMID: 22728314 DOI: 10.1016/j.neuropharm.2012.06.026] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/13/2012] [Accepted: 06/14/2012] [Indexed: 12/30/2022]
Abstract
Caffeine is commonly consumed in an effort to enhance cognitive performance. However, little is known about the usefulness of caffeine with regard to memory enhancement, with previous studies showing inconsistent effects on memory performance. We aimed to determine the effect of caffeine on working memory (WM) load-related activation during encoding, maintenance and retrieval phases of a WM maintenance task using functional magnetic resonance imaging (fMRI). 20 healthy, male, habitual caffeine consumers aged 40-61 years were administered 100 mg of caffeine in a double-blind placebo-controlled crossover design. Participants were scanned in a non-withdrawn state following a workday during which caffeinated products were consumed according to individual normal use (range = 145-595 mg). Acute caffeine administration was associated with increased load-related activation compared to placebo in the left and right dorsolateral prefrontal cortex during WM encoding, but decreased load-related activation in the left thalamus during WM maintenance. These findings are indicative of an effect of caffeine on the fronto-parietal network involved in the top-down cognitive control of WM processes during encoding and an effect on the prefrontal cortico-thalamic loop involved in the interaction between arousal and the top-down control of attention during maintenance. Therefore, the effects of caffeine on WM may be attributed to both a direct effect of caffeine on WM processes, as well as an indirect effect on WM via arousal modulation. Behavioural and fMRI results were more consistent with a detrimental effect of caffeine on WM at higher levels of WM load, than caffeine-related WM enhancement. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Elissa B Klaassen
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, The Netherlands.
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50
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Addicott MA, Peiffer AM, Laurienti PJ. The Effects of Dietary Caffeine Use and Abstention on Blood Oxygen Level-Dependent Activation and Cerebral Blood Flow. JOURNAL OF CAFFEINE RESEARCH 2012; 2:15-22. [PMID: 24761265 DOI: 10.1089/jcr.2011.0027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Caffeine is a known vasoconstrictor that reduces resting cerebral blood flow (CBF) throughout the brain. This effect may be problematic in functional magnetic resonance imaging (fMRI) research, as the blood oxygen level-dependent (BOLD) signal is a complex interaction of CBF and other factors that are dependent on changes in neural activity. It is unknown whether changes in the BOLD signal during an fMRI experiment could be affected by subjects' recent use or abstinence from dietary caffeine. METHODS Here, we report two similar studies (n=45 and 17) that measure the effects of caffeine on BOLD activation, BOLD time course parameters, and CBF. Using a factorial design, low, moderate, and high caffeine consumers received either caffeine (250 mg) or placebo during normal caffeine use (satiated state) or after 30 hours of abstention (abstinent state). The fMRI of a reaction time task and resting-state CBF were collected. RESULTS In general, acute caffeine administration reduced the time to peak and full width at half maximum of the BOLD time course, and CBF across both studies. Caffeine also produced a small reduction in BOLD activation. The majority of these reductions across measures were moderated by neither the level of caffeine use, nor the abstinent or satiated state. CONCLUSIONS These results suggest that dietary caffeine use does not produce a significant effect on task-related BOLD activation.
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Affiliation(s)
- Merideth A Addicott
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center , Durham, North Carolina
| | - Ann M Peiffer
- Department of Radiation Oncology, Wake Forest University School of Medicine , Winston-Salem, North Carolina
| | - Paul J Laurienti
- Department of Radiology, Wake Forest University School of Medicine , Winston-Salem, North Carolina
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