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Amatngalim GD, Rodenburg LW, Delpiano L, Smits SMA, Aalbers BL, van der Ent CK, Gray MA, Beekman JM. WS16.05 Identification of drugs activating CFTR-independent fluid secretion in nasal organoids based on a high-content screening assay. J Cyst Fibros 2022. [DOI: 10.1016/s1569-1993(22)00247-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kutyla MJ, Gray MA, von Hippel C, Hourigan LF, Kendall BJ, Whaley AJ, O'Connor S, Holtmann GJ. Improving the Quality of Bowel Preparation: Rewarding Patients for Success or Intensive Patient Education? Dig Dis 2020; 39:113-118. [PMID: 32720916 DOI: 10.1159/000510461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/22/2020] [Indexed: 02/02/2023]
Abstract
INTRODUCTION AND OBJECTIVES The quality of the bowel preparation is a critical parameter for the outcome of colonoscopies. It is well established that the bowel preparation modality (e.g., split or larger volume preparation) significantly improves the quality of the bowel preparation. Patient compliance is another important factor impacting on the quality of bowel preparations that receives relatively little research attention. We aimed to explore if intensified education or a lottery ticket as reward for good bowel preparation could improve outcomes. METHODS After informed consent, all patients received a standardized printed information booklet. In a randomized fashion, patients were offered (a) a lottery scratchy ticket with an opportunity to win $25,000 as "reward" for good bowel preparation, (b) an education session delivered over the phone by a trained nurse, or (c) no additional measure. RESULTS Overall, the quality of the bowel preparation was rated good or very good in 69.1% (95% CI 61.7-75.7%) of patients. Reward intervention did not influence the quality of bowel preparation (OR 0.42, 95% CI 0.09-1.91, p = 0.260); however, bowel preparation quality decreased in patients randomized to receive the additional education (OR 0.28, 95% CI 0.08-0.96, p = 0.042). Neither intervention significantly impacted on polyp detection rates. CONCLUSIONS Contrasting general beliefs, additional interventions (e.g., incentives or phone consultation) did not improve the quality of the bowel preparation. The unexpected result shows that utilizing extra resources must be balanced against real-world outcomes and may not always provide the expected result.
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Affiliation(s)
- Marguerite J Kutyla
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia.,School of Pharmacy, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Marcus A Gray
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia.,School of Psychology, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Queensland, Australia.,Translational Research Institute, Brisbane, Queensland, Australia
| | - Courtney von Hippel
- School of Psychology, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Luke F Hourigan
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Bradley J Kendall
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Amanda J Whaley
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia
| | - Sam O'Connor
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia
| | - Gerald J Holtmann
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia, .,Translational Research Institute, Brisbane, Queensland, Australia, .,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia, .,Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Queensland, Australia,
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Gray MA, Chao CY, Staudacher HM, Kolosky NA, Talley NJ, Holtmann G. Anti-TNFα therapy in IBD alters brain activity reflecting visceral sensory function and cognitive-affective biases. PLoS One 2018. [PMID: 29518097 PMCID: PMC5843226 DOI: 10.1371/journal.pone.0193542] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background In inflammatory bowel disease (IBD), immune activation with increased circulating TNF-α is linked to the intensity of gastrointestinal symptoms and depression or anxiety. A central feature of depression is cognitive biases linked to negative attributions about self, the world and the future. We aimed to assess the effects of anti-TNFα therapy on the central processing of self-attribution biases and visceral afferent information in patients with Crohn’s disease. Methods We examined 9 patients with Crohn’s disease (age 26.1±10.6. yrs, 5 female, 5 ileocolonic, 2 colonic and 2 ileal disease) during chronic anti-TNFα therapy (5 adalimumab, 4 infliximab). Patients were studied twice in randomized order before and after anti-TNFα administration. On each occasion patients underwent functional magnetic resonance imaging (fMRI) of the brain during a test of implicit attribution biases regarding sickness/health and undertook a standardized nutrient challenge. Results Following anti-TNFα treatment, ratings of ‘fullness’ following nutrient challenge reduced compared to pre-treatment ratings (p<0.05). Reaction times revealed improved processing of self-related and positive health words, consistent with improved implicit sense of wellbeing that correlated with improvements in sensory function after treatment (r = 0.67, p<0.05). Treatment-associated improvements in implicit processing were mirrored by alterations of prefrontal, amygdala, posterior cingulate and visual regions. Between patients, the degree of functional amygdala change was additionally explained by individual differences in attention regulation and body awareness rankings. Conclusion In patients with Crohn’s disease, anti-TNFα administration reduces visceral sensitivity and improves implicit cognitive-affective biases linked to alterations in limbic (amygdala) function.
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Affiliation(s)
- Marcus A. Gray
- Department of Gastroenterology & Hepatology, Princess Alexandra Hospital Brisbane, Queensland, Australia
- Translational Research Institute, Brisbane, Queensland, Australia
- Faculty of Health and Behavioral Science, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
- * E-mail:
| | - Che-yung Chao
- Department of Gastroenterology & Hepatology, Princess Alexandra Hospital Brisbane, Queensland, Australia
| | - Heidi M. Staudacher
- Department of Gastroenterology & Hepatology, Princess Alexandra Hospital Brisbane, Queensland, Australia
- Translational Research Institute, Brisbane, Queensland, Australia
| | - Natasha A. Kolosky
- Department of Gastroenterology & Hepatology, Princess Alexandra Hospital Brisbane, Queensland, Australia
- Translational Research Institute, Brisbane, Queensland, Australia
- Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
- Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia
| | - Nicholas J. Talley
- Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia
| | - Gerald Holtmann
- Department of Gastroenterology & Hepatology, Princess Alexandra Hospital Brisbane, Queensland, Australia
- Translational Research Institute, Brisbane, Queensland, Australia
- Faculty of Health and Behavioral Science, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
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Critchley HD, Nicotra A, Chiesa PA, Nagai Y, Gray MA, Minati L, Bernardi L. Slow breathing and hypoxic challenge: cardiorespiratory consequences and their central neural substrates. PLoS One 2015; 10:e0127082. [PMID: 25973923 PMCID: PMC4431729 DOI: 10.1371/journal.pone.0127082] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 04/11/2015] [Indexed: 11/19/2022] Open
Abstract
Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge.
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Affiliation(s)
- Hugo D. Critchley
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- * E-mail:
| | - Alessia Nicotra
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Patrizia A. Chiesa
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Ghermann Laboratory, University of Queensland, Queensland, Australia
| | - Yoko Nagai
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | | | | | - Luciano Bernardi
- Department of Internal Medicine, University of Pavia and Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
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Umeda S, Harrison NA, Gray MA, Mathias CJ, Critchley HD. Structural brain abnormalities in postural tachycardia syndrome: A VBM-DARTEL study. Front Neurosci 2015; 9:34. [PMID: 25852449 PMCID: PMC4362313 DOI: 10.3389/fnins.2015.00034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 01/22/2015] [Indexed: 11/21/2022] Open
Abstract
Postural tachycardia syndrome (PoTS), a form of dysautonomia, is characterized by orthostatic intolerance, and is frequently accompanied by a range of symptoms including palpitations, lightheadedness, clouding of thought, blurred vision, fatigue, anxiety, and depression. Although the estimated prevalence of PoTS is approximately 5–10 times as common as the better-known condition orthostatic hypotension, the neural substrates of the syndrome are poorly characterized. In the present study, we used magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) applying the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) procedure to examine variation in regional brain structure associated with PoTS. We recruited 11 patients with established PoTS and 23 age-matched normal controls. Group comparison of gray matter volume revealed diminished gray matter volume within the left anterior insula, right middle frontal gyrus and right cingulate gyrus in the PoTS group. We also observed lower white matter volume beneath the precentral gyrus and paracentral lobule, right pre- and post-central gyrus, paracentral lobule and superior frontal gyrus in PoTS patients. Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores. Together, these findings of structural differences, particularly within insular and cingulate components of the salience network, suggest a link between dysregulated physiological reactions arising from compromised central autonomic control (and interoceptive representation) and increased vulnerability to psychiatric symptoms in PoTS patients.
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Affiliation(s)
- Satoshi Umeda
- Department of Psychology, Keio University Tokyo, Japan ; Autonomic Unit, National Hospital for Neurology and Neurosurgery, University College London London, UK
| | - Neil A Harrison
- Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex Brighton, UK ; Sussex Partnership NHS Foundation Trust Brighton, UK ; Sackler Centre for Consciousness Science, University of Sussex Brighton, UK
| | - Marcus A Gray
- Centre for Advanced Imaging, The University of Queensland St. Lucia, QLD, Australia ; Royal Brisbane and Women's Hospital Herston, QLD, Australia
| | - Christopher J Mathias
- Autonomic Unit, National Hospital for Neurology and Neurosurgery, University College London London, UK ; Neurovascular Medicine, Imperial College London at St. Mary's Hospital London, UK
| | - Hugo D Critchley
- Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex Brighton, UK ; Sussex Partnership NHS Foundation Trust Brighton, UK ; Sackler Centre for Consciousness Science, University of Sussex Brighton, UK
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Citron FMM, Gray MA, Critchley HD, Weekes BS, Ferstl EC. Emotional valence and arousal affect reading in an interactive way: neuroimaging evidence for an approach-withdrawal framework. Neuropsychologia 2014; 56:79-89. [PMID: 24440410 PMCID: PMC4098114 DOI: 10.1016/j.neuropsychologia.2014.01.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 11/29/2013] [Accepted: 01/03/2014] [Indexed: 12/03/2022]
Abstract
A growing body of literature shows that the emotional content of verbal material affects reading, wherein emotional words are given processing priority compared to neutral words. Human emotions can be conceptualised within a two-dimensional model comprised of emotional valence and arousal (intensity). These variables are at least in part distinct, but recent studies report interactive effects during implicit emotion processing and relate these to stimulus-evoked approach-withdrawal tendencies. The aim of the present study was to explore how valence and arousal interact at the neural level, during implicit emotion word processing. The emotional attributes of written word stimuli were orthogonally manipulated based on behavioural ratings from a corpus of emotion words. Stimuli were presented during an fMRI experiment while 16 participants performed a lexical decision task, which did not require explicit evaluation of a word′s emotional content. Results showed greater neural activation within right insular cortex in response to stimuli evoking conflicting approach-withdrawal tendencies (i.e., positive high-arousal and negative low-arousal words) compared to stimuli evoking congruent approach vs. withdrawal tendencies (i.e., positive low-arousal and negative high-arousal words). Further, a significant cluster of activation in the left extra-striate cortex was found in response to emotional than neutral words, suggesting enhanced perceptual processing of emotionally salient stimuli. These findings support an interactive two-dimensional approach to the study of emotion word recognition and suggest that the integration of valence and arousal dimensions recruits a brain region associated with interoception, emotional awareness and sympathetic functions. Emotional valence and arousal affect reading interactively. Positive high-arousal and negative low-arousal words evoke conflicting reactions. Enhanced right insula activation was found in response to conflicting stimuli. Insula integrates viscero-sensory and cognitive/evaluative information. Enhanced extra-striate cortex activation was found for emotional than neutral words.
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Affiliation(s)
- Francesca M M Citron
- Cluster of Excellence "Languages of Emotion", Freie Universität Berlin, Habelschwerdter Allee 45, D-14195 Berlin, Germany.
| | - Marcus A Gray
- Centre for Advanced Imaging, The University of Queensland, Australia; Psychiatry, Brighton & Sussex Medical School, Universities of Brighton and Sussex, UK
| | - Hugo D Critchley
- Psychiatry, Brighton & Sussex Medical School, Universities of Brighton and Sussex, UK; Sussex Partnership NHS Foundation Trust, Brighton, UK; Sackler Centre for Consciousness Science, University of Sussex, UK
| | - Brendan S Weekes
- Laboratory for Communication Science, The University of Hong Kong, China
| | - Evelyn C Ferstl
- Center for Cognitive Science, Albert-Ludwigs-Universität Freiburg, Germany
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Georgiou-Karistianis N, Poudel GR, Domínguez D JF, Langmaid R, Gray MA, Churchyard A, Chua P, Borowsky B, Egan GF, Stout JC. Functional andconnectivity changes during working memory inHuntington’s disease: 18month longitudinal data from the IMAGE-HD study. Brain Cogn 2013; 83:80-91. [DOI: 10.1016/j.bandc.2013.07.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/04/2013] [Accepted: 07/16/2013] [Indexed: 12/15/2022]
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Domínguez D JF, Egan GF, Gray MA, Poudel GR, Churchyard A, Chua P, Stout JC, Georgiou-Karistianis N. Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study. PLoS One 2013; 8:e74131. [PMID: 24066104 PMCID: PMC3774648 DOI: 10.1371/journal.pone.0074131] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 08/01/2013] [Indexed: 11/19/2022] Open
Abstract
IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI) study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively). In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume) and microstructural (diffusivity) longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter) and in caudate and putamen (volume and diffusivity change). Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years), close to diagnosis (<15 years) and after diagnosis. Of the two diffusion metrics (mean diffusivity, MD; fractional anisotropy, FA), only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.
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Affiliation(s)
- Juan F. Domínguez D
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
| | - Gary F. Egan
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
- Monash Biomedical Imaging (MBI), Monash University, Melbourne, Victoria, Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Melbourne, Victoria, Australia
- Centre for Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Marcus A. Gray
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
- Monash Biomedical Imaging (MBI), Monash University, Melbourne, Victoria, Australia
- Centre for Advanced Imaging, Gehrmann Laboratory, the University of Queensland, St Lucia, Queensland, Australia
| | - Govinda R. Poudel
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
- Monash Biomedical Imaging (MBI), Monash University, Melbourne, Victoria, Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Melbourne, Victoria, Australia
| | - Andrew Churchyard
- Department of Neurology, Monash Medical Centre, Clayton, Victoria, Australia
| | - Phyllis Chua
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
| | - Julie C. Stout
- School of Psychology and Psychiatry, Monash University, Clayton, Victoria, Australia
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Judák L, Hegyi P, Rakonczay Z, Maléth J, Gray MA, Venglovecz V. Ethanol and its non-oxidative metabolites profoundly inhibit CFTR function in pancreatic epithelial cells which is prevented by ATP supplementation. Pflugers Arch 2013; 466:549-62. [PMID: 23948742 DOI: 10.1007/s00424-013-1333-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/26/2013] [Accepted: 07/30/2013] [Indexed: 02/06/2023]
Abstract
Excessive alcohol consumption is a major cause of acute pancreatitis, but the mechanism involved is not well understood. Recent investigations suggest that pancreatic ductal epithelial cells (PDECs) help defend the pancreas from noxious agents such as alcohol. Because the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel plays a major role in PDEC physiology and mutated CFTR is often associated with pancreatitis, we tested the hypothesis that ethanol affects CFTR to impair ductal function. Electrophysiological studies on native PDECs showed that ethanol (10 and 100 mM) increased basal, but reversibly blocked, forskolin-stimulated CFTR currents. The inhibitory effect of ethanol was mimicked by its non-oxidative metabolites, palmitoleic acid ethyl ester (POAEE) and palmitoleic acid (POA), but not by the oxidative metabolite, acetaldehyde. Ethanol, POAEE and POA markedly reduced intracellular ATP (ATPi) which was linked to CFTR inhibition since the inhibitory effects were almost completely abolished if ATPi depletion was prevented. We propose that ethanol causes functional damage of CFTR through an ATPi-dependent mechanism, which compromises ductal fluid secretion and likely contributes to the pathogenesis of acute pancreatitis. We suggest that the maintenance of ATPi may represent a therapeutic option in the treatment of the disease.
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Affiliation(s)
- L Judák
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
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Radulescu E, Minati L, Ganeshan B, Harrison NA, Gray MA, Beacher FDCC, Chatwin C, Young RCD, Critchley HD. Abnormalities in fronto-striatal connectivity within language networks relate to differences in grey-matter heterogeneity in Asperger syndrome. Neuroimage Clin 2013; 2:716-26. [PMID: 24179823 PMCID: PMC3777793 DOI: 10.1016/j.nicl.2013.05.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/16/2013] [Accepted: 05/17/2013] [Indexed: 12/14/2022]
Abstract
Asperger syndrome (AS) is an Autism Spectrum Disorder (ASD) characterised by qualitative impairment in the development of emotional and social skills with relative preservation of general intellectual abilities, including verbal language. People with AS may nevertheless show atypical language, including rate and frequency of speech production. We previously observed that abnormalities in grey matter homogeneity (measured with texture analysis of structural MR images) in AS individuals when compared with controls are also correlated with the volume of caudate nucleus. Here, we tested a prediction that these distributed abnormalities in grey matter compromise the functional integrity of brain networks supporting verbal communication skills. We therefore measured the functional connectivity between caudate nucleus and cortex during a functional neuroimaging study of language generation (verbal fluency), applying psycho-physiological interaction (PPI) methods to test specifically for differences attributable to grey matter heterogeneity in AS participants. Furthermore, we used dynamic causal modelling (DCM) to characterise the causal directionality of these differences in interregional connectivity during word production. Our results revealed a diagnosis-dependent influence of grey matter heterogeneity on the functional connectivity of the caudate nuclei with right insula/inferior frontal gyrus and anterior cingulate, respectively with the left superior frontal gyrus and right precuneus. Moreover, causal modelling of interactions between inferior frontal gyri, caudate and precuneus, revealed a reliance on bottom-up (stimulus-driven) connections in AS participants that contrasted with a dominance of top-down (cognitive control) connections from prefrontal cortex observed in control participants. These results provide detailed support for previously hypothesised central disconnectivity in ASD and specify discrete brain network targets for diagnosis and therapy in ASD. We used MRI techniques to assess the connectivity in language networks in AS. Grey-matter heterogeneity of MR images correlated with volume of caudate in AS. Hence, caudate nuclei were used as seed ROIs in connectivity analyses: PPI, DCM. Grey-matter heterogeneity differently tuned caudate connectivity in AS, controls. DCM of language circuitry featured bottom-up models in AS and top-down in controls.
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Affiliation(s)
- Eugenia Radulescu
- Psychiatry, Brighton & Sussex Medical School (BSMS), Brighton, BN1 9RY, UK ; Sackler Centre for Consciousness Science, University of Sussex, Brighton, BN1 9RY, UK
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Beacher FDCC, Radulescu E, Minati L, Baron-Cohen S, Lombardo MV, Lai MC, Walker A, Howard D, Gray MA, Harrison NA, Critchley HD. Sex differences and autism: brain function during verbal fluency and mental rotation. PLoS One 2012; 7:e38355. [PMID: 22701630 PMCID: PMC3373504 DOI: 10.1371/journal.pone.0038355] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 05/08/2012] [Indexed: 12/30/2022] Open
Abstract
Autism spectrum conditions (ASC) affect more males than females. This suggests that the neurobiology of autism: 1) may overlap with mechanisms underlying typical sex-differentiation or 2) alternately reflect sex-specificity in how autism is expressed in males and females. Here we used functional magnetic resonance imaging (fMRI) to test these alternate hypotheses. Fifteen men and fourteen women with Asperger syndrome (AS), and sixteen typically developing men and sixteen typically developing women underwent fMRI during performance of mental rotation and verbal fluency tasks. All groups performed the tasks equally well. On the verbal fluency task, despite equivalent task-performance, both males and females with AS showed enhanced activation of left occipitoparietal and inferior prefrontal activity compared to controls. During mental rotation, there was a significant diagnosis-by-sex interaction across occipital, temporal, parietal, middle frontal regions, with greater activation in AS males and typical females compared to AS females and typical males. These findings suggest a complex relationship between autism and sex that is differentially expressed in verbal and visuospatial domains.
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Affiliation(s)
- Felix D. C. C. Beacher
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Department of Biomedical Engineering, Stony Brook University School of Medicine, Stony Brook, New York, United States of America
| | - Eugenia Radulescu
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
| | - Ludovico Minati
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Scientific Department and Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico “Carlo Besta”, Milano, Italy
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
| | - Michael V. Lombardo
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
| | - Meng-Chuan Lai
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
| | - Anne Walker
- Neurobehavioural Clinic, Sussex Partnership NHS Foundation Trust, c/o Sussex Education Centre, Mill View Hospital Site, Hove, United Kingdom
| | - Dawn Howard
- Neurobehavioural Clinic, Sussex Partnership NHS Foundation Trust, c/o Sussex Education Centre, Mill View Hospital Site, Hove, United Kingdom
| | - Marcus A. Gray
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Experimental Neuropsychology Research Unit School of Psychology, Psychiatry Faculty of Medicine Nursing & Health Sciences, Monash University Clayton, Victoria, Australia
| | - Neil A. Harrison
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Neurobehavioural Clinic, Sussex Partnership NHS Foundation Trust, c/o Sussex Education Centre, Mill View Hospital Site, Hove, United Kingdom
| | - Hugo D. Critchley
- Psychiatry, Brighton & Sussex Medical School, Brighton, United Kingdom
- Sackler Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Neurobehavioural Clinic, Sussex Partnership NHS Foundation Trust, c/o Sussex Education Centre, Mill View Hospital Site, Hove, United Kingdom
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Eccles JA, Beacher FDC, Gray MA, Jones CL, Minati L, Harrison NA, Critchley HD. Brain structure and joint hypermobility: relevance to the expression of psychiatric symptoms. Br J Psychiatry 2012; 200:508-9. [PMID: 22539777 PMCID: PMC3365276 DOI: 10.1192/bjp.bp.111.092460] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Joint hypermobility is overrepresented among people with anxiety and can be associated with abnormal autonomic reactivity. We tested for associations between regional cerebral grey matter and hypermobility in 72 healthy volunteers using voxel-based morphometry of structural brain scans. Strikingly, bilateral amygdala volume distinguished those with from those without hypermobility. The hypermobility group scored higher for interoceptive sensitivity yet were not significantly more anxious. Our findings specifically link hypermobility to the structural integrity of a brain centre implicated in normal and abnormal emotions and physiological responses. Our observations endorse hypermobility as a multisystem phenotype and suggest potential mechanisms mediating clinical vulnerability to neuropsychiatric symptoms.
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Radulescu E, Ganeshan B, Minati L, Beacher FDCC, Gray MA, Chatwin C, Young RCD, Harrison NA, Critchley HD. Gray matter textural heterogeneity as a potential in-vivo biomarker of fine structural abnormalities in Asperger syndrome. Pharmacogenomics J 2012; 13:70-9. [DOI: 10.1038/tpj.2012.3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Affiliation(s)
- Marcus A Gray
- Brighton and Sussex Medical School (BSMS), University of Sussex, Centre for Consciousness Science, Brighton, UK.
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Jones CL, Gray MA, Minati L, Simner J, Critchley HD, Ward J. The neural basis of illusory gustatory sensations: two rare cases of lexical-gustatory synaesthesia. J Neuropsychol 2012; 5:243-54. [PMID: 21923788 DOI: 10.1111/j.1748-6653.2011.02013.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lexical-gustatory synaesthesia is a rare phenomenon in which the individual experiences flavour sensations when they read, hear, or imagine words. In this study, we provide insight into the neural basis of this form of synaesthesia using functional neuroimaging. Words known to evoke pleasant, neutral, and unpleasant synaesthetic tastes and synaesthetically tasteless words were presented to two lexical-gustatory synaesthetes, during fMRI scanning. Ten non-synaesthetic participants were also scanned on the same list of words. The synaesthetic brain displayed a different pattern of activity to words when compared to the non-synaesthetes, with insula activation related to viewing words that elicited tastes that have an associated emotional valence (i.e., pleasant or unpleasant tastes). The subjective intensity of the synaesthesia was correlated with activity in the medial parietal lobes (precuneus/retrosplenial cortex), which are implicated in polymodal imagery and self-directed thought. This region has also previously been activated in studies of lexical-colour synaesthesia, suggesting its role may not be limited to the type of synaesthesia explored here.
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Affiliation(s)
- C L Jones
- Psychiatry, Brighton and Sussex Medical School, UK.
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Beacher FD, Minati L, Baron-Cohen S, Lombardo MV, Lai MC, Gray MA, Harrison NA, Critchley HD. Autism attenuates sex differences in brain structure: a combined voxel-based morphometry and diffusion tensor imaging study. AJNR Am J Neuroradiol 2011; 33:83-9. [PMID: 22173769 DOI: 10.3174/ajnr.a2880] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE It has been proposed that autism spectrums condition may represent a form of extreme male brain (EMB), a notion supported by psychometric, behavioral, and endocrine evidence. Yet, limited data are presently available evaluating this hypothesis in terms of neuroanatomy. Here, we investigated sex-related anatomic features in adults with AS, a "pure" form of autism not involving major developmental delay. MATERIALS AND METHODS Males and females with AS and healthy controls (n = 28 and 30, respectively) were recruited. Structural MR imaging was performed to measure overall gray and white matter volume and to assess regional effects by means of VBM. DTI was used to investigate the integrity of the main white matter tracts. RESULTS Significant interactions were found between sex and diagnosis in total white matter volume, regional gray matter volume in the right parietal operculum, and fractional anisotropy (FA) in the body of the CC, cingulum, and CR. Post hoc comparisons indicated that the typical sexual dimorphism found in controls, whereby males have larger FA and total white matter volume, was absent or attenuated in participants with AS. CONCLUSIONS Our results point to a fundamental role of the factors that underlie sex-specific brain differentiation in the etiology of autism.
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Affiliation(s)
- F D Beacher
- Department of Psychiatry and Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Falmer, UK
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17
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Duka T, Trick L, Nikolaou K, Gray MA, Kempton MJ, Williams H, Williams SCR, Critchley HD, Stephens DN. Unique brain areas associated with abstinence control are damaged in multiply detoxified alcoholics. Biol Psychiatry 2011; 70:545-52. [PMID: 21612768 PMCID: PMC3165202 DOI: 10.1016/j.biopsych.2011.04.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 04/01/2011] [Accepted: 04/02/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND The ability to abstain from drinking, despite incentives to imbibe, is essential to recovery from alcoholism. METHODS We used an incentive conflict task to investigate ability to abstain from responding during presentations of incentive cues. Both alcoholic (n = 23) and healthy subjects (n = 22) were required to withhold responding during the simultaneous presentation of two visual stimuli in which the individual presentation allowed responding for monetary reward. Brain structures activated during performance of the task were studied using functional magnetic resonance imaging in healthy volunteers (n = 8), and changes in gray matter volume were studied in a separate group of patients (n = 29) compared with control subjects (n = 31) in regions of interest identified on functional magnetic resonance imaging. RESULTS Abstinent alcoholic patients were severely impaired on the incentive conflict task. The impairment was greater in patients with experience of several versus a single detoxification. Healthy volunteers, during the same incentive conflict task, showed distinct patterns of brain activation (including gyrus rectus, ventromedial prefrontal cortex, and superior frontal gyrus). Reduction of gray matter volume in ventromedial prefrontal cortex and superior frontal gyrus of patients was more extensive in those with multiple detoxifications. CONCLUSIONS Performance deficits in alcoholics are associated with withdrawal-induced impairments in prefrontal subfields, which are exacerbated following repeated episodes of detoxification. Detoxification thus compromises functional and structural integrity of prefrontal cortex and may thus impair the ability to control future drinking. Performance in the incentive conflict task is a sensitive biomarker for such deficits.
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Affiliation(s)
- Theodora Duka
- School of Psychology, University of Sussex, Brighton, United Kingdom.
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Rusted J, Ruest T, Gray MA. Acute effects of nicotine administration during prospective memory, an event related fMRI study. Neuropsychologia 2011; 49:2362-8. [PMID: 21530557 DOI: 10.1016/j.neuropsychologia.2011.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 02/17/2011] [Accepted: 04/11/2011] [Indexed: 11/30/2022]
Abstract
We previously demonstrated that stimulating neuronal nicotinic acetylcholine receptors modulates prospective memory (PM), the ability to remember and implement a prior intention. Here we used fMRI to explore the neuronal correlates of acute nicotinic (1mg) modulation during PM, employing a double blind, valence-matched placebo-controlled design, and a solely event-related analysis. Eight healthy adults completed on two occasions (1 week washout) a simple attentional task containing infrequent PM trials. PM activated bilateral parietal, prefrontal (BA10) and anterior cingulate, and deactivated genual cingulate and medial prefrontal regions. Further, acute nicotine administration decreased activity within a largely overlapping right parietal region. This data validates a purely event-related approach to exploring PM, and suggests procholinergic modulation of PM by parietal rather than BA10/frontal regions.
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Affiliation(s)
- Jennifer Rusted
- School of Psychology, University of Sussex, Brighton, East Sussex BN1 9QG, United Kingdom.
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Critchley HD, Nagai Y, Gray MA, Mathias CJ. Dissecting axes of autonomic control in humans: Insights from neuroimaging. Auton Neurosci 2011; 161:34-42. [DOI: 10.1016/j.autneu.2010.09.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 09/08/2010] [Accepted: 09/09/2010] [Indexed: 12/30/2022]
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Beacher FDCC, Gray MA, Minati L, Whale R, Harrison NA, Critchley HD. Acute tryptophan depletion attenuates conscious appraisal of social emotional signals in healthy female volunteers. Psychopharmacology (Berl) 2011; 213:603-13. [PMID: 20596858 PMCID: PMC3032182 DOI: 10.1007/s00213-010-1897-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 05/10/2010] [Indexed: 11/16/2022]
Abstract
RATIONALE Acute tryptophan depletion (ATD) decreases levels of central serotonin. ATD thus enables the cognitive effects of serotonin to be studied, with implications for the understanding of psychiatric conditions, including depression. OBJECTIVE To determine the role of serotonin in conscious (explicit) and unconscious/incidental processing of emotional information. MATERIALS AND METHODS A randomized, double-blind, cross-over design was used with 15 healthy female participants. Subjective mood was recorded at baseline and after 4 h, when participants performed an explicit emotional face processing task, and a task eliciting unconscious processing of emotionally aversive and neutral images presented subliminally using backward masking. RESULTS ATD was associated with a robust reduction in plasma tryptophan at 4 h but had no effect on mood or autonomic physiology. ATD was associated with significantly lower attractiveness ratings for happy faces and attenuation of intensity/arousal ratings of angry faces. ATD also reduced overall reaction times on the unconscious perception task, but there was no interaction with emotional content of masked stimuli. ATD did not affect breakthrough perception (accuracy in identification) of masked images. CONCLUSIONS ATD attenuates the attractiveness of positive faces and the negative intensity of threatening faces, suggesting that serotonin contributes specifically to the appraisal of the social salience of both positive and negative salient social emotional cues. We found no evidence that serotonin affects unconscious processing of negative emotional stimuli. These novel findings implicate serotonin in conscious aspects of active social and behavioural engagement and extend knowledge regarding the effects of ATD on emotional perception.
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Affiliation(s)
- Felix D C C Beacher
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School (BSMS), Brighton & Hove, UK.
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Gray MA, Minati L, Paoletti G, Critchley HD. Baroreceptor activation attenuates attentional effects on pain-evoked potentials. Pain 2010; 151:853-861. [PMID: 20965656 PMCID: PMC3038268 DOI: 10.1016/j.pain.2010.09.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 08/16/2010] [Accepted: 09/22/2010] [Indexed: 01/03/2023]
Abstract
Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis, we explored in a group of healthy participants the combined effects of cue-induced expectancy and baroreceptor activity on the amplitude of pain-evoked ERPs. Brief nociceptive skin stimuli were delivered during a simple visual task; half were preceded by a visual forewarning cue, and half were unpredictable. Nociceptive stimuli were timed to coincide either with systole (maximum activation of cardiac baroreceptors) or with diastole (minimum baroreceptor activation). We observed a strong interaction between expectancy and cardiac timing for the amplitude of the P2 ERP component; no effects were observed for the N2 component. Cued stimuli were associated with larger P2 amplitude, but this effect was abolished for stimuli presented during baroreceptor activation. No cardiac timing effect was observed for un-cued stimuli. Taken together, these findings suggest a close integration of cognitive-affective aspects of expectancy and baroreceptor influences on pain, and as such may cast further light on mechanisms underlying mental and physiological contributions to clinical pain.
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Affiliation(s)
- Marcus A. Gray
- Clinical Imaging Sciences Centre (CISC), Brighton and Sussex Medical School (BSMS), University of Sussex, Brighton, East Sussex, BN1 9RR, UK
- Experimental Neuropsychology Research Unit, School of Psychology and Psychiatry, Monash University 3800, Australia
| | - Ludovico Minati
- Clinical Imaging Sciences Centre (CISC), Brighton and Sussex Medical School (BSMS), University of Sussex, Brighton, East Sussex, BN1 9RR, UK
- Scientific Department, Fondazione IRCCS Istituto Neurologico “Carlo Besta”, Milano, Italy
| | | | - Hugo D. Critchley
- Clinical Imaging Sciences Centre (CISC), Brighton and Sussex Medical School (BSMS), University of Sussex, Brighton, East Sussex, BN1 9RR, UK
- Sussex Partnership Foundation (NHS) Trust, Sussex, UK
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Harrison NA, Gray MA, Gianaros PJ, Critchley HD. The embodiment of emotional feelings in the brain. J Neurosci 2010; 30:12878-84. [PMID: 20861391 PMCID: PMC3044882 DOI: 10.1523/jneurosci.1725-10.2010] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 08/04/2010] [Accepted: 08/11/2010] [Indexed: 12/16/2022] Open
Abstract
Central to Walter Cannon's challenge to peripheral theories of emotion was that bodily arousal responses are too undifferentiated to account for the wealth of emotional feelings. Despite considerable evidence to the contrary, this remains widely accepted and for nearly a century has left the issue of whether visceral afferent signals are essential for emotional experience unresolved. Here we combine functional magnetic resonance imaging and multiorgan physiological recording to dissect experience of two distinct disgust forms and their relationship to peripheral and central physiological activity. We show that experience of core and body-boundary-violation disgust are dissociable in both peripheral autonomic and central neural responses and also that emotional experience specific to anterior insular activity encodes these different underlying patterns of peripheral physiological responses. These findings demonstrate that organ-specific physiological responses differentiate emotional feeling states and support the hypothesis that central representations of organism physiological homeostasis constitute a critical aspect of the neural basis of feelings.
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Affiliation(s)
- Neil A Harrison
- Department of Psychiatry, Brighton and Sussex Medical School, Sackler Centre for Consciousness Science, University of Sussex, Brighton BN1 9PR, United Kingdom.
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Kemp AH, Quintana DS, Gray MA, Felmingham KL, Brown K, Gatt JM. Impact of depression and antidepressant treatment on heart rate variability: a review and meta-analysis. Biol Psychiatry 2010; 67:1067-74. [PMID: 20138254 DOI: 10.1016/j.biopsych.2009.12.012] [Citation(s) in RCA: 802] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 12/06/2009] [Indexed: 11/27/2022]
Abstract
BACKGROUND Depression is associated with an increase in the likelihood of cardiac events; however, studies investigating the relationship between depression and heart rate variability (HRV) have generally focused on patients with cardiovascular disease (CVD). The objective of the current report is to examine with meta-analysis the impact of depression and antidepressant treatment on HRV in depressed patients without CVD. METHODS Studies comparing 1) HRV in patients with major depressive disorder and healthy control subjects and 2) the HRV of patients with major depressive disorder before and after treatment were considered for meta-analysis. RESULTS Meta-analyses were based on 18 articles that met inclusion criteria, comprising a total of 673 depressed participants and 407 healthy comparison participants. Participants with depression had lower HRV (time frequency: Hedges' g = -.301, p < .001; high frequency: Hedges' g = -.293, p < .001; nonlinear: Hedges' g = -1.955, p = .05; Valsalva ratio: Hedges' g = -.712, p < .001) than healthy control subjects, and depression severity was negatively correlated with HRV (r = -.354, p < .001). Tricyclic medication decreased HRV, although serotonin reuptake inhibitors, mirtazapine, and nefazodone had no significant impact on HRV despite patient response to treatment. CONCLUSIONS Depression without CVD is associated with reduced HRV, which decreases with increasing depression severity, most apparent with nonlinear measures of HRV. Critically, a variety of antidepressant treatments do not resolve these decreases despite resolution of symptoms, highlighting that antidepressant medications might not have HRV-mediated cardioprotective effects and the need to identify individuals at risk among patients in remission.
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Affiliation(s)
- Andrew H Kemp
- School of Psychology, University of Sydney, Sydney, Australia.
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Gray MA, Minati L, Harrison NA, Gianaros PJ, Napadow V, Critchley HD. Physiological recordings: basic concepts and implementation during functional magnetic resonance imaging. Neuroimage 2009; 47:1105-15. [PMID: 19460445 PMCID: PMC2741582 DOI: 10.1016/j.neuroimage.2009.05.033] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/01/2009] [Accepted: 05/09/2009] [Indexed: 12/30/2022] Open
Abstract
Combining human functional neuroimaging with other forms of psychophysiological measurement, including autonomic monitoring, provides an empirical basis for understanding brain-body interactions. This approach can be applied to characterize unwanted physiological noise, examine the neural control and representation of bodily processes relevant to health and morbidity, and index covert expression of affective and cognitive processes to enhance the interpretation of task-evoked regional brain activity. In recent years, human neuroimaging has been dominated by functional magnetic resonance imaging (fMRI) studies. The spatiotemporal information of fMRI regarding central neural activity is valuably complemented by parallel physiological monitoring, yet such studies still remain in the minority. This review article highlights fMRI studies that employed cardiac, vascular, respiratory, electrodermal, gastrointestinal and pupillary psychophysiological indices to address specific questions regarding interaction between brain and bodily state in the context of experience, cognition, emotion and behaviour. Physiological monitoring within the fMRI environment presents specific technical issues, most importantly related to safety. Mechanical and electrical hazards may present dangers to scanned subjects, operator and/or equipment. Furthermore, physiological monitoring may interfere with the quality of neuroimaging data, or itself be compromised by artefacts induced by the operation of the scanner. We review the sources of these potential problems and the current approaches and advice to enable the combination of fMRI and physiological monitoring in a safe and effective manner.
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Affiliation(s)
- Marcus A Gray
- Clinical Imaging Sciences Centre and Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex, Falmer Campus, UK.
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Harrison NA, Brydon L, Walker C, Gray MA, Steptoe A, Critchley HD. Inflammation causes mood changes through alterations in subgenual cingulate activity and mesolimbic connectivity. Biol Psychiatry 2009; 66:407-14. [PMID: 19423079 PMCID: PMC2885494 DOI: 10.1016/j.biopsych.2009.03.015] [Citation(s) in RCA: 531] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Revised: 03/14/2009] [Accepted: 03/16/2009] [Indexed: 12/27/2022]
Abstract
BACKGROUND Inflammatory cytokines are implicated in the pathophysiology of depression. In rodents, systemically administered inflammatory cytokines induce depression-like behavior. Similarly in humans, therapeutic interferon-alpha induces clinical depression in a third of patients. Conversely, patients with depression also show elevated pro-inflammatory cytokines. OBJECTIVES To determine the neural mechanisms underlying inflammation-associated mood change and modulatory effects on circuits involved in mood homeostasis and affective processing. METHODS In a double-blind, randomized crossover study, 16 healthy male volunteers received typhoid vaccination or saline (placebo) injection in two experimental sessions. Mood questionnaires were completed at baseline and at 2 and 3 hours. Two hours after injection, participants performed an implicit emotional face perception task during functional magnetic resonance imaging. Analyses focused on neurobiological correlates of inflammation-associated mood change and affective processing within regions responsive to emotional expressions and implicated in the etiology of depression. RESULTS Typhoid but not placebo injection produced an inflammatory response indexed by increased circulating interleukin-6 and significant mood reduction at 3 hours. Inflammation-associated mood deterioration correlated with enhanced activity within subgenual anterior cingulate cortex (sACC) (a region implicated in the etiology of depression) during emotional face processing. Furthermore, inflammation-associated mood change reduced connectivity of sACC to amygdala, medial prefrontal cortex, nucleus accumbens, and superior temporal sulcus, which was modulated by peripheral interleukin-6. CONCLUSIONS Inflammation-associated mood deterioration is reflected in changes in sACC activity and functional connectivity during evoked responses to emotional stimuli. Peripheral cytokines modulate this mood-dependent sACC connectivity, suggesting a common pathophysiological basis for major depressive disorder and sickness-associated mood change and depression.
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Affiliation(s)
- Neil A Harrison
- Wellcome Trust, Centre for Neuroimaging, Institute of Cognitive Neuroscience, UCL, 17 Queen Square, London WC1N 3AR, UK.
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Harrison NA, Brydon L, Walker C, Gray MA, Steptoe A, Dolan RJ, Critchley HD. Neural origins of human sickness in interoceptive responses to inflammation. Biol Psychiatry 2009; 66:415-22. [PMID: 19409533 PMCID: PMC2885492 DOI: 10.1016/j.biopsych.2009.03.007] [Citation(s) in RCA: 236] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 01/26/2009] [Accepted: 02/23/2009] [Indexed: 11/25/2022]
Abstract
BACKGROUND Inflammation is associated with psychological, emotional, and behavioral disturbance, known as sickness behavior. Inflammatory cytokines are implicated in coordinating this central motivational reorientation accompanying peripheral immunologic responses to pathogens. Studies in rodents suggest an afferent interoceptive neural mechanism, although comparable data in humans are lacking. METHODS In a double-blind, randomized crossover study, 16 healthy male volunteers received typhoid vaccination or saline (placebo) injection in two experimental sessions. Profile of Mood State questionnaires were completed at baseline and at 2 and 3 hours. Two hours after injection, participants performed a high-demand color word Stroop task during functional magnetic resonance imaging. Blood samples were performed at baseline and immediately after scanning. RESULTS Typhoid but not placebo injection produced a robust inflammatory response indexed by increased circulating interleukin-6 accompanied by a significant increase in fatigue, confusion, and impaired concentration at 3 hours. Performance of the Stroop task under inflammation activated brain regions encoding representations of internal bodily state. Spatial and temporal characteristics of this response are consistent with interoceptive information flow via afferent autonomic fibers. During performance of this task, activity within interoceptive brain regions also predicted individual differences in inflammation-associated but not placebo-associated fatigue and confusion. Maintenance of cognitive performance, despite inflammation-associated fatigue, led to recruitment of additional prefrontal cortical regions. CONCLUSIONS These findings suggest that peripheral infection selectively influences central nervous system function to generate core symptoms of sickness and reorient basic motivational states.
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Affiliation(s)
- Neil A. Harrison
- Wellcome Trust, Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom,Institute of Cognitive Neuroscience, University College London, London, United Kingdom,Address correspondence to Neil Harrison, M.B.B.S., Ph.D., UCL Institute of Cognitive Neuroscience, Alexandra House, University College London, 17 Queen Square, London WC1N 3AR, UK
| | - Lena Brydon
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Cicely Walker
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Marcus A. Gray
- Brighton and Sussex Medical School, University of Sussex Campus, Falmer, Brighton, United Kingdom
| | - Andrew Steptoe
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Raymond J. Dolan
- Wellcome Trust, Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Hugo D. Critchley
- Brighton and Sussex Medical School, University of Sussex Campus, Falmer, Brighton, United Kingdom
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Beacher FDCC, Gray MA, Mathias CJ, Critchley HD. Vulnerability to simple faints is predicted by regional differences in brain anatomy. Neuroimage 2009; 47:937-45. [PMID: 19464376 PMCID: PMC2726440 DOI: 10.1016/j.neuroimage.2009.05.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 05/01/2009] [Accepted: 05/12/2009] [Indexed: 01/21/2023] Open
Abstract
Neurocardiogenic syncope (NCS, simple fainting) is a common and typically benign familial condition, which rarely may result in traumatic injury or hypoxic convulsions. NCS is associated with emotional triggers, anxiety states and stress. However, the etiology of NCS, as a psychophysiological process, is poorly understood. We therefore investigated the relationship between NCS and brain anatomy. We studied a non-clinical sample of eighteen individuals with histories characteristic of NCS, and nineteen matched controls who had never fainted. We recorded fainting frequency, resting heart rate variability measures and anxiety levels. Structural T1-weighted magnetic resonance images (MRI) were acquired at 1.5 T. Associations between brain morphometry (regional gray and white matter volumes) and NCS, resting physiology and anxiety were tested using voxel-based morphometry (VBM). Compared to controls, NCS participants had lower regional brain volume within medulla and midbrain (a priori regions of interest). Moreover, across NCS individuals, lower gray matter volume in contiguous regions of left caudate nucleus predicted enhanced parasympathetic cardiac tone, fainting frequency and anxiety levels. Our findings provide preliminary evidence for a hierarchical anatomical basis to NCS. First, differences in the volume of brainstem centers supporting cardiovascular homeostasis may relate to constitutional predisposition to NCS. Second, differences in the structural organization of the caudate nucleus in NCS individuals may relate to fainting frequency via interactions between emotional state and parasympathetic control of the heart. These observations highlight the application of VBM to the identification of neurovisceral mechanisms relevant to psychosomatic medicine and the neuroscience of emotion.
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Affiliation(s)
- Felix D C C Beacher
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, BN1 9RY, UK.
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Abstract
Covert exchange of autonomic responses may shape social affective behavior, as observed in mirroring of pupillary responses during sadness processing. We examined how, independent of facial emotional expression, dynamic coherence between one's own and another's pupil size modulates regional brain activity. Fourteen subjects viewed pairs of eye stimuli while undergoing fMRI. Using continuous pupillometry biofeedback, the size of the observed pupils was varied, correlating positively or negatively with changes in participants’ own pupils. Viewing both static and dynamic stimuli activated right fusiform gyrus. Observing dynamically changing pupils activated STS and amygdala, regions engaged by non-static and salient facial features. Discordance between observed and observer's pupillary changes enhanced activity within bilateral anterior insula, left amygdala and anterior cingulate. In contrast, processing positively correlated pupils enhanced activity within left frontal operculum. Our findings suggest pupillary signals are monitored continuously during social interactions and that incongruent changes activate brain regions involved in tracking motivational salience and attentionally meaningful information. Naturalistically, dynamic coherence in pupillary change follows fluctuations in ambient light. Correspondingly, in social contexts discordant pupil response is likely to reflect divergence of dispositional state. Our data provide empirical evidence for an autonomically mediated extension of forward models of motor control into social interaction.
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Venglovecz V, Rakonczay Z, Ozsvári B, Takács T, Lonovics J, Varró A, Gray MA, Argent BE, Hegyi P. Effects of bile acids on pancreatic ductal bicarbonate secretion in guinea pig. Gut 2008; 57:1102-12. [PMID: 18303091 DOI: 10.1136/gut.2007.134361] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND AND AIMS Acute pancreatitis is associated with significant morbidity and mortality. Bile reflux into the pancreas is a common cause of acute pancreatitis and, although the bile can reach both acinar and ductal cells, most research to date has focused on the acinar cells. The aim of the present study was to investigate the effects of bile acids on HCO(3)(-) secretion from the ductal epithelium. METHODS Isolated guinea pig intralobular/interlobular pancreatic ducts were microperfused and the effects of unconjugated chenodeoxycholate (CDC) and conjugated glycochenodeoxycholate (GCDC) on intracellular calcium concentration ([Ca(2+)](i)) and pH (pH(i)) were measured using fluorescent dyes. Changes of pH(i) were used to calculate the rates of acid/base transport across the duct cell membranes. RESULTS Luminal administration of a low dose of CDC (0.1 mM) stimulated ductal HCO(3)(-) secretion, which was blocked by luminal H(2)DIDS (dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid). In contrast, both luminal and basolateral administration of a high dose of CDC (1 mM) strongly inhibited HCO(3)(-) secretion. Both CDC and GCDC elevated [Ca(2+)](i), and this effect was blocked by BAPTA-AM (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid), caffeine, xestospongin C and the phospholipase C inhibitor U73122. BAPTA-AM also inhibited the stimulatory effect of low doses of CDC on HCO(3)(-) secretion, but did not modulate the inhibitory effect of high doses of CDC. CONCLUSIONS It is concluded that the HCO(3)(-) secretion stimulated by low concentrations of bile acids acts to protect the pancreas against toxic bile, whereas inhibition of HCO(3)(-) secretion by high concentrations of bile acids may contribute to the progression of acute pancreatitis.
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Affiliation(s)
- V Venglovecz
- First Department of Medicine, University of Szeged, Szeged, Hungary
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Pirie ES, Gray MA. Exploring the assessors' and nurses' experience of formal assessment of clinical competency in the administration of blood components. Nurse Educ Pract 2007; 7:215-27. [PMID: 17689447 DOI: 10.1016/j.nepr.2006.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 08/23/2006] [Accepted: 08/23/2006] [Indexed: 10/24/2022]
Abstract
Blood transfusion, clinical competency, assessment, evaluation The change in nurse education from apprenticeship training to the higher education setting, has raised concerns about the lack of practical skills newly qualified nurses have on registration. Every practitioner must be able to administer blood components safely however, the Serious Hazards of Transfusion (SHOT) scheme have consistently demonstrated that 'wrong blood' incidents are the major cause of morbidity and mortality related to transfusion in the United Kingdom. As a result the SHOT working group have recommended that all practitioners should have their clinical competency formally assessed. This paper describes the development and evaluation of a tool for assessing clinical competency for staff involved in transfusing blood. The evaluation used a triangulated approach of phenomenology and survey. The tool was piloted in two different clinical settings by four registered nurses who each assessed two nurses. Individual semi-structured interviews were conducted to collate the nurses' and the assessors' experience of the process. The study participants were of the opinion that assessing clinical competency using a criterion-referenced tool gave practitioners the opportunity to relate theory to practice, promote best practice and encourage adherence to hospital transfusion policies. Formal assessment of clinical competency is therefore, a vehicle that could be used to promote safe transfusion practice, ensuring the safety of patients is paramount.
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Affiliation(s)
- E S Pirie
- Transfusion Nurse Specialist, Effective Use of Blood Group, Scottish National Blood Transfusion Service, 21 Ellen's Glen Road, Edinburgh EH17 7QT, Scotland, United Kingdom.
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Ferrari S, Griesenbach U, Iida A, Farley R, Wright AM, Zhu J, Munkonge FM, Smith SN, You J, Ban H, Inoue M, Chan M, Singh C, Verdon B, Argent BE, Wainwright B, Jeffery PK, Geddes DM, Porteous DJ, Hyde SC, Gray MA, Hasegawa M, Alton EWFW. Sendai virus-mediated CFTR gene transfer to the airway epithelium. Gene Ther 2007; 14:1371-9. [PMID: 17597790 DOI: 10.1038/sj.gt.3302991] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The potential for gene therapy to be an effective treatment for cystic fibrosis has been hampered by the limited gene transfer efficiency of current vectors. We have shown that recombinant Sendai virus (SeV) is highly efficient in mediating gene transfer to differentiated airway epithelial cells, because of its capacity to overcome the intra- and extracellular barriers known to limit gene delivery. Here, we have identified a novel method to allow the cystic fibrosis transmembrane conductance regulator (CFTR) cDNA sequence to be inserted within SeV (SeV-CFTR). Following in vitro transduction with SeV-CFTR, a chloride-selective current was observed using whole-cell and single-channel patch-clamp techniques. SeV-CFTR administration to the nasal epithelium of cystic fibrosis (CF) mice (Cftr(G551D) and Cftr(tm1Unc)TgN(FABPCFTR)#Jaw mice) led to partial correction of the CF chloride transport defect. In addition, when compared to a SeV control vector, a higher degree of inflammation and epithelial damage was found in the nasal epithelium of mice treated with SeV-CFTR. Second-generation transmission-incompetent F-deleted SeV-CFTR led to similar correction of the CF chloride transport defect in vivo as first-generation transmission-competent vectors. Further modifications to the vector or the host may make it easier to translate these studies into clinical trials of cystic fibrosis.
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Affiliation(s)
- S Ferrari
- Department of Gene Therapy, Faculty of Medicine, Imperial College, National Heart and Lung Institute, London, UK
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Gray MA, Harrison NA, Wiens S, Critchley HD. Modulation of emotional appraisal by false physiological feedback during fMRI. PLoS One 2007; 2:e546. [PMID: 17579718 PMCID: PMC1890305 DOI: 10.1371/journal.pone.0000546] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Accepted: 05/25/2007] [Indexed: 12/30/2022] Open
Abstract
Background James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined. Methodology/Principal Findings We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level. Conclusions/Significance Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order “cognitive” representations of bodily arousal state.
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Affiliation(s)
- Marcus A Gray
- Clinical Imaging Sciences Centre, Brighton Sussex Medical School, University of Sussex, Brighton, United Kingdom; Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.
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Abstract
Awareness of one's physiology is an important component of emotion. How might these processes be related to addiction? In a recent issue of Science, Naqvi et al. demonstrated that smoking addiction is disrupted by damage to the insula cortex. This suggests that brain circuits mediating interoception also contribute to craving states.
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Affiliation(s)
- Marcus A Gray
- Brighton and Sussex Medical School, University of Sussex Falmer Campus, Brighton BN1 6PX, United Kingdom.
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Gray MA, Taggart P, Sutton PM, Groves D, Holdright DR, Bradbury D, Brull D, Critchley HD. A cortical potential reflecting cardiac function. Proc Natl Acad Sci U S A 2007; 104:6818-23. [PMID: 17420478 PMCID: PMC1871868 DOI: 10.1073/pnas.0609509104] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Emotional trauma and psychological stress can precipitate cardiac arrhythmia and sudden death through arrhythmogenic effects of efferent sympathetic drive. Patients with preexisting heart disease are particularly at risk. Moreover, generation of proarrhythmic activity patterns within cerebral autonomic centers may be amplified by afferent feedback from a dysfunctional myocardium. An electrocortical potential reflecting afferent cardiac information has been described, reflecting individual differences in interoceptive sensitivity (awareness of one's own heartbeats). To inform our understanding of mechanisms underlying arrhythmogenesis, we extended this approach, identifying electrocortical potentials corresponding to the cortical expression of afferent information about the integrity of myocardial function during stress. We measured changes in cardiac response simultaneously with electroencephalography in patients with established ventricular dysfunction. Experimentally induced mental stress enhanced cardiovascular indices of sympathetic activity (systolic blood pressure, heart rate, ventricular ejection fraction, and skin conductance) across all patients. However, the functional response of the myocardium varied; some patients increased, whereas others decreased, cardiac output during stress. Across patients, heartbeat-evoked potential amplitude at left temporal and lateral frontal electrode locations correlated with stress-induced changes in cardiac output, consistent with an afferent cortical representation of myocardial function during stress. Moreover, the amplitude of the heartbeat-evoked potential in the left temporal region reflected the proarrhythmic status of the heart (inhomogeneity of left ventricular repolarization). These observations delineate a cortical representation of cardiac function predictive of proarrhythmic abnormalities in cardiac repolarization. Our findings highlight the dynamic interaction of heart and brain in stress-induced cardiovascular morbidity.
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Affiliation(s)
- Marcus A Gray
- Functional Imaging Laboratory, Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, United Kingdom.
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Linley JE, Simmons NL, Gray MA. Extracellular zinc stimulates a calcium-activated chloride conductance through mobilisation of intracellular calcium in renal inner medullary collecting duct cells. Pflugers Arch 2006; 453:487-95. [PMID: 17021797 DOI: 10.1007/s00424-006-0139-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/13/2006] [Accepted: 07/18/2006] [Indexed: 10/24/2022]
Abstract
We have used the perforated patch clamp and fura-2 fluorescence techniques to study the effect of extracellular Zn(2+) on whole-cell Ca(2+)-activated Cl(-) currents (I (CLCA)) in mouse inner medullary collecting duct cells (mIMCD-3). I (CLCA) was spontaneously active in 74% of cells under basal conditions and displayed time and voltage-independent kinetics and an outwardly rectifying current/voltage relationship (I/V). Addition of zinc chloride (10-400 microM) to the bathing solution resulted in a dose-dependent increase in I (CLCA) with little change in Cl(-) selectivity or biophysical characteristics, whereas gadolinium chloride (30 microM) and lanthanum chloride (100 microM) had no significant effect on the whole-cell current. Using fura-2-loaded mIMCD-3 cells, extracellular Zn(2+) (400 microM) stimulated an increase in intracellular Ca(2+) to an elevated plateau. The Zn(2+)-stimulated [Ca(2+)](i) increase was inhibited by thapsigargin (200 nM), the IP(3) receptor antagonist 2-aminoethoxydiphenyl borate (10 microM) and removal of bath Ca(2+). Pre-exposure to Zn(2+) (400 microM) markedly attenuated the ATP (100 microM)-stimulated [Ca(2+)](i) increase. These data are consistent with the hypothesis that extracellular Zn(2+) stimulates an increase in [Ca(2+)](i) by a release of calcium from thapsigargin/IP(3) sensitive stores. A possible physiological role for a divalent metal ion receptor, distinct from the extracellular Ca(2+)-sensing receptor, in IMCD cells is discussed.
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Affiliation(s)
- J E Linley
- Institute of Cell and Molecular Biosciences, University Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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Gray MA. Primary cilia and regulation of renal Na+ transport. Focus on "Heightened epithelial Na+ channel-mediated Na+ absorption in a murine polycystic kidney disease model epithelium lacking apical monocilia". Am J Physiol Cell Physiol 2006; 290:C947-9. [PMID: 16531571 DOI: 10.1152/ajpcell.00640.2005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Gray MA, Peake SJ, Farrell AP, Bruch R. Acute didecyl dimethyl ammonium chloride toxicity to larval lake sturgeon, Acipenser fulvescens Rafinesque, walleye Sander vitreus Mitchill, and northern pike, Esox lucius Linnaeus. Bull Environ Contam Toxicol 2005; 75:890-6. [PMID: 16400575 DOI: 10.1007/s00128-005-0833-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Accepted: 08/26/2005] [Indexed: 05/06/2023]
Affiliation(s)
- M A Gray
- Canadian Rivers Institute and Department of Zoology, University of Manitoba, Winnipeg, Manitoba, Canada
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Cunjak RA, Roussel JM, Gray MA, Dietrich JP, Cartwright DF, Munkittrick KR, Jardine TD. Using stable isotope analysis with telemetry or mark-recapture data to identify fish movement and foraging. Oecologia 2005; 144:636-46. [PMID: 15959824 DOI: 10.1007/s00442-005-0101-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 03/11/2005] [Indexed: 11/25/2022]
Abstract
Information about animal movements has often been inferred from stable isotope analysis (SIA), but is dependent on animals assimilating site-specific isotopic signatures via diet. This potential weakness in ecological interpretation can be overcome by using other investigative tools that provide precise information about individual movement patterns. In this paper, we demonstrate the value of combining SIA with telemetry or mark-recapture data from trapping, electrofishing and remote detection of individuals to study the movement and feeding ecology of fishes in different habitats. In a fjord lake system in Newfoundland, Canada, juvenile Atlantic salmon delayed downstream migration (smolts) or actively moved into a large lake (parr) where they foraged for periods reflecting different life history strategies. In the Miramichi River (New Brunswick, Canada), SIA provided evidence of distinct foraging habitats (tributary versus large river). By tracking fish implanted with passive integrated transponder (PIT) tags, we distinguished between movements related to foraging versus seeking cool water refugia during high temperature events. Finally, site fidelity and limited mobility of slimy sculpin, a small benthic fish, was established where delta13C in muscle tissue showed a progressive enrichment downstream and where a median displacement of <10 m was estimated for sculpin tagged with PIT tags. Technological improvements have permitted non-destructive tissue sampling of wild fishes for SIA, and the tagging and remote detection of animals smaller than was previously possible. These advancements and the combination of investigative tools promise new insights into animal ecology.
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Affiliation(s)
- R A Cunjak
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada, E3B 5A3.
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Lu K, Gray MA, Oliver C, Liley DT, Harrison BJ, Bartholomeusz CF, Phan KL, Nathan PJ. The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum Psychopharmacol 2004; 19:457-65. [PMID: 15378679 DOI: 10.1002/hup.611] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
L-Theanine (delta-glutamylethylamide) is one of the predominant amino acids ordinarily found in green tea, and historically has been used as a relaxing agent. The current study examined the acute effects of L-theanine in comparison with a standard benzodiazepine anxiolytic, alprazolam and placebo on behavioural measures of anxiety in healthy human subjects using the model of anticipatory anxiety (AA). Sixteen healthy volunteers received alprazolam (1 mg), L-theanine (200 mg) or placebo in a double-blind placebo-controlled repeated measures design. The acute effects of alprazolam and L-theanine were assessed under a relaxed and experimentally induced anxiety condition. Subjective self-reports of anxiety including BAI, VAMS, STAI state anxiety, were obtained during both task conditions at pre- and post-drug administrations. The results showed some evidence for relaxing effects of L-theanine during the baseline condition on the tranquil-troubled subscale of the VAMS. Alprazolam did not exert any anxiolytic effects in comparison with the placebo on any of the measures during the relaxed state. Neither L-theanine nor alprazalam had any significant anxiolytic effects during the experimentally induced anxiety state. The findings suggest that while L-theanine may have some relaxing effects under resting conditions, neither L-theanine not alprazolam demonstrate any acute anxiolytic effects under conditions of increased anxiety in the AA model.
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Affiliation(s)
- Kristy Lu
- Neuropsychopharmacology Laboratory, Brain Sciences Institute, Swinburne, University of Technology, Victoria, Australia
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Kemp AH, Gray MA, Silberstein RB, Armstrong SM, Nathan PJ. Augmentation of serotonin enhances pleasant and suppresses unpleasant cortical electrophysiological responses to visual emotional stimuli in humans. Neuroimage 2004; 22:1084-96. [PMID: 15219580 DOI: 10.1016/j.neuroimage.2004.03.022] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 03/11/2004] [Accepted: 03/11/2004] [Indexed: 11/21/2022] Open
Abstract
The serotonergic system is one of the major systems targeted in the pharmacological treatment of a wide range of mood disorders including depression; however, little is known about the neurophysiological mechanisms underlying the effects of serotonin (5-HT) on affective phenomena including emotional behaviours, mood and emotional processing. The aim of the current study was to investigate how 5-HT acutely modulates steady-state visually evoked potentials (SSVEP), heart rate (HR) and verbal ratings associated with the viewing of differently valent emotional images. In a randomised double-blind, placebo-controlled design, 17 healthy subjects were tested under two acute treatment conditions: placebo and citalopram (20 mg) (a selective serotonin re-uptake inhibitor, or SSRI). Participants were tested 2 h post treatment whilst viewing 75 images (categorised as pleasant, neutral or unpleasant). Results indicate that under placebo treatment, processing of unpleasant valence [unpleasant (-) neutral images] was associated with decreases in SSVEP amplitude and latency in frontal and occipital cortices, whereas processing of pleasant valence [pleasant (-) neutral images] was associated with amplitude decreases and latency increases within frontal and left temporoparietal cortices. Decreases in both amplitude and latency are both interpreted as surrogate measures of cortical activation or excitation. Citalopram relative to placebo attenuated the electrophysiological activation to unpleasant valence within frontal and occipital cortices, but potentiated electrophysiological activation (amplitude only) to pleasant valence within parietooccipital cortices. Citalopram relative to placebo also suppressed differences in heart rate associated with the viewing of pleasant and unpleasant images, but did not alter subject's subjective responses to emotional images. Results suggest that responsiveness to pleasant and unpleasant stimuli following neurochemical modulation may vary across different response systems (i.e. self-report, HR and SSVEP). Electrophysiological findings suggest that acute serotonergic augmentation with citalopram modulates cortical processing of emotionally valent stimuli such that response to pleasant valence is potentiated and response to unpleasant valence is suppressed. The findings suggest a possible neurophysiological mechanism underlying antidepressant drug action on emotion.
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Affiliation(s)
- Andrew H Kemp
- Neuropsychopharmacology Laboratory, Brain Sciences Institute, Swinburne University of Technology, Hawthorn VIC 3122, Australia
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Boese SH, Aziz O, Simmons NL, Gray MA. Kinetics and regulation of a Ca2+-activated Cl- conductance in mouse renal inner medullary collecting duct cells. Am J Physiol Renal Physiol 2003; 286:F682-92. [PMID: 14678946 DOI: 10.1152/ajprenal.00123.2003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Using the whole cell patch-clamp technique, a Ca2+-activated Cl- conductance (CaCC) was transiently activated by extracellular ATP (100 microM) in primary cultures of mouse inner medullary collecting duct (IMCD) cells and in the mouse IMCD-K2 cell line. ATP also transiently increased intracellular Ca2+ concentration ([Ca2+]i) from 100 nM to peak values of approximately 750 nM in mIMCD-K2 cells, with a time course similar to the ATP-induced activation and decay of the CaCC. Removal of extracellular Ca2+ had no major effect on the peak Cl- conductance or the increase in [Ca2+]i induced by ATP, suggesting that Ca2+ released from intracellular stores directly activates the CaCC. In mIMCD-K2 cells, a rectifying time- and voltage-dependent current was observed when [Ca2+]i was fixed via the patch pipette to between 100 and 500 nM. Maximal activation occurred at approximately 1 microM [Ca2+]i, with currents losing any kinetics and displaying a linear current-voltage relationship. From Ca2+-dose-response curves, an EC50 value of approximately 650 nM at -80 mV was obtained, suggesting that under physiological conditions the CaCC would be near fully activated by mucosal nucleotides. Noise analysis of whole cell currents in mIMCD-K2 cells suggests a single-channel conductance of 6-8 pS and a density of approximately 5,000 channels/cell. In conclusion, the CaCC in mouse IMCD cells is a low-conductance, nucleotide-sensitive Cl- channel, whose activity is tightly coupled to changes in [Ca2+]i over the normal physiological range.
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Affiliation(s)
- S H Boese
- School of Cell and Molecular Bioscience, Univ. Medical School, Newcastle Upon Tyne, NE2 4HH, UK
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Kemp AH, Gray MA, Eide P, Silberstein RB, Nathan PJ. Steady-state visually evoked potential topography during processing of emotional valence in healthy subjects. Neuroimage 2002; 17:1684-92. [PMID: 12498742 DOI: 10.1006/nimg.2002.1298] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The International Affective Picture System (IAPS) is increasingly used in brain imaging studies to examine emotional processes. This task allows valence and arousal content to be systematically investigated; however, previous studies have generally failed to select images that vary in one dimension as well as hold constant the variability on the other dimension. In addition, no studies have investigated the temporal structure associated with the conscious, ongoing processing of emotional stimuli following systematic selection of IAPS images. The aim of the present study was therefore to use steady-state probe topography (SSPT) to examine the steady-state visually evoked potentials (SSVEPs) associated with the processing of pleasant and unpleasant images low in arousal content. Seventy-five IAPS images, categorized as unpleasant, neutral, or pleasant, were presented to 16 healthy subjects while brain activity was recorded from 64 scalp sites. Analysis subtracted the activity associated with the presentation of neutral images from the activity associated with the presentation of pleasant as well as unpleasant images. Results demonstrate that both pleasant and unpleasant valence is associated with transient, widespread, and bilateral frontal SSVEP latency reductions. Unpleasant images were also associated with a transient bilateral anterior frontal amplitude decrease. Latency reductions are interpreted as increases in neural information processing speed, while amplitude reductions are interpreted in the current paper as analogous to an event-related desynchronisation commonly associated with the alpha bandwidth. These key findings support previous literature in terms of there being substantial overlap in frontal neural circuitry when the brain processes pleasant and unpleasant valence relative to neutral valence.
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Affiliation(s)
- A H Kemp
- Brain Sciences Institute, Swinburne University of Technology, 400 Burwood Road, Hawthorn VIC 3122, Australia
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Gray MA. Designer pharmacotherapy for the treatment of cystic fibrosis: commentary on Zegarra-Moran et al. Br J Pharmacol 2002; 137:411-2. [PMID: 12359621 PMCID: PMC1573509 DOI: 10.1038/sj.bjp.0704883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- M A Gray
- Department of Physiological Sciences, University Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Dormer RL, Dérand R, McNeilly CM, Mettey Y, Bulteau-Pignoux L, Métayé T, Vierfond JM, Gray MA, Galietta LJ, Morris MR, Pereira MM, Doull IJ, Becq F, McPherson MA. Correction of delF508-CFTR activity with benzo(c)quinolizinium compounds through facilitation of its processing in cystic fibrosis airway cells. J Cell Sci 2001; 114:4073-81. [PMID: 11739639 DOI: 10.1242/jcs.114.22.4073] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A number of genetic diseases, including cystic fibrosis, have been identified as disorders of protein trafficking associated with retention of mutant protein within the endoplasmic reticulum. In the presence of the benzo(c)quinolizinium drugs, MPB-07 and its congener MPB-91, we show the activation of cystic fibrosis transmembrane conductance regulator (CFTR) delF508 channels in IB3-1 human cells, which express endogenous levels of delF508-CFTR. These drugs were without effect on the Ca2+-activated Cl– transport, whereas the swelling-activated Cl– transport was found altered in MPB-treated cells. Immunoprecipitation and in vitro phosphorylation shows a 20% increase of the band C form of delF508 after MPB treatment. We then investigated the effect of these drugs on the extent of mislocalisation of delF508-CFTR in native airway cells from cystic fibrosis patients. We first showed that delF508 CFTR was characteristically restricted to an endoplasmic reticulum location in approximately 80% of untreated cells from CF patients homozygous for the delF508-CFTR mutation. By contrast, 60-70% of cells from non-CF patients showed wild-type CFTR in an apical location. MPB-07 treatment caused dramatic relocation of delF508-CFTR to the apical region such that the majority of delF508/delF508 CF cells showed a similar CFTR location to that of wild-type. MPB-07 had no apparent effect on the distribution of wild-type CFTR, the apical membrane protein CD59 or the ER membrane Ca2+,Mg-ATPase. We also showed a similar pharmacological effect in nasal cells freshly isolated from a delF508/G551D CF patient. The results demonstrate selective redirection of a mutant membrane protein using cell-permeant small molecules of the benzo(c)quinolizinium family and provide a major advance towards development of a targetted drug treatment for cystic fibrosis and other disorders of protein trafficking.
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Affiliation(s)
- R L Dormer
- Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff, Wales CF14 4XN, UK.
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Sayer JA, Stewart GS, Boese SH, Gray MA, Pearce SH, Goodship TH, Simmons NL. The voltage-dependent Cl(-) channel ClC-5 and plasma membrane Cl(-) conductances of mouse renal collecting duct cells (mIMCD-3). J Physiol 2001; 536:769-83. [PMID: 11691871 PMCID: PMC2278912 DOI: 10.1111/j.1469-7793.2001.00769.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
1. We have tested the hypothesis that the voltage-dependent Cl(-) channel, ClC-5 functions as a plasma membrane Cl(-) conductance in renal inner medullary collecting duct cells. 2. Full-length mouse kidney ClC-5 (mClC-5) was cloned and transiently expressed in CHO-K1 cells. Fast whole-cell patch-clamp recordings confirmed that mClC-5 expression produces a voltage-dependent, strongly outwardly rectifying Cl(-) conductance that was unaffected by external DIDS. 3. Slow whole-cell recordings, using nystatin-perforated patches from transfected CHO-K1 cells, also produced voltage-dependent Cl(-) currents consistent with ClC-5 expression. However, under this recording configuration an endogenous DIDS-sensitive Ca(2+)-activated Cl(-) conductance was also evident, which appeared to be activated by green fluorescent protein (GFP) transfection. 4. A mClC-5-GFP fusion protein was transiently expressed in CHO-K1 cells; confocal laser scanning microscopy (CLSM) showed localization at the plasma membrane, consistent with patch-clamp experiments. 5. Endogenous expression of mClC-5 was demonstrated in mouse renal collecting duct cells (mIMCD-3) by RT-PCR and by immunocytochemistry. 6. Using slow whole-cell current recordings, mIMCD-3 cells displayed three biophysically distinct Cl(-)-selective currents, which were all inhibited by DIDS. However, no cells exhibited whole-cell currents that had mClC-5 characteristics. 7. Transient transfection of mIMCD-3 cells with antisense mClC-5 had no effect on the endogenous Cl(-) conductances. Transient transfection with sense mClC-5 failed to induce the Cl(-) conductance seen in CHO-K1 cells but stimulated levels of the endogenous Ca(2+)-activated Cl(-) conductance 24 h post-transfection. 8. Confocal laser scanning microscopy of mIMCD-3 cells transfected with mClC-5-GFP showed that the protein was absent from the plasma membrane and was instead localized to acidic endosomal compartments. 9. These data discount a major role for ClC-5 as a plasma membrane Cl(-) conductance in mIMCD-3 cells but suggest a role in endosomal function.
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Affiliation(s)
- J A Sayer
- Department of Physiological Sciences, Medical School, Framlington Place, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, UK
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Sohma Y, Gray MA, Imai Y, Argent BE. 150 mM HCO3(-)--how does the pancreas do it? Clues from computer modelling of the duct cell. JOP 2001; 2:198-202. [PMID: 11875259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
Cystic fibrosis (CF) takes its name from the pathological changes that occur in the pancreas. Cystic fibrosis transmembrane conductance regulator (CFTR) is highly expressed in the pancreatic ductal epithelium and plays a key role in ductal HCO(3)(-) secretion. In humans, the pancreatic duct secretes near isotonic NaHCO(3). Experimental data suggests that HCO(3)(-) secretion occurs via apical Cl(-)/HCO(3)(-) exchangers working in parallel with Cl(-) channels (CFTR and calcium activated chloride channels, CaCC). Programming the currently available experimental data into our computer model (based on network thermodynamics) shows that while the anion exchanger/Cl(-) channel mechanism will produce a relatively large volume of a HCO(3)(-)-rich fluid, it can only raise the luminal HCO(3)(-) concentration up to about 70 mM. To achieve secretion of about 150 mM NaHCO(3) it is necessary to modulate the properties of the apical membrane transporters as the secreted fluid flows down the ductal system. On the basis of our computer simulations, we propose that HCO(3)(-) secretion occurs mainly via the exchanger in duct segments near the acini (luminal HCO(3)(-) concentration up to about 70 mM), but mainly via channels further down the ductal tree (raising luminal HCO(3)(-) to about 150 mM). We speculate that the switch between these two secretory mechanisms is controlled by a series of luminal signals (e.g. pH, HCO(3)(-) concentration) acting on the apical membrane transporters in the duct cell.
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Affiliation(s)
- Y Sohma
- Department of Physiology, Osaka Medical College, Takatsuki, Osaka, Japan
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Gray MA, O'Reilly C, Winpenny J, Argent B. Functional interactions of HCO3- with cystic fibrosis transmembrane conductance regulator. JOP 2001; 2:207-11. [PMID: 11875261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Disruption of normal cystic fibrosis transmembrane conductance regulator- (CFTR)-mediated Cl(-) transport is associated with cystic fibrosis (CF). CFTR is also required for HCO(3)(-) transport in many tissues such as the lungs, gastro-intestinal tract, and pancreas, although the exact role CFTR plays is uncertain. Given the importance of CFTR in HCO(3)(-) transport by so many CF-affected organ systems, it is perhaps surprising that relatively little is known about the interactions of HCO(3)(-) ions with CFTR. We have used patch clamp recordings from native pancreatic duct cells to study HCO(3)(-) permeation and interaction with CFTR. Ion selectivity studies shows that CFTR is between 3-5 times more selective for Cl(-) over HCO(3)(-). In addition, extracellular HCO(3)(-) has a novel inhibitory effect on cAMP-stimulated CFTR currents carried by Cl(-). The block by HCO(3)(-) was rapid, relatively independent of voltage and occurred over the physiological range of HCO(3)(-) concentrations. These data show that luminal HCO(3)(-) acts as a potent regulator of CFTR, and suggests that inhibition involves an external anion-binding site on the channel. This work has implications not only for elucidating mechanisms of HCO(3)(-) transport in epithelia, but also for approaches used to treat CF.
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Affiliation(s)
- M A Gray
- Department of Physiological Sciences, University Medical School, Newcastle upon Tyne, United Kingdom.
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Huebner RC, Gray MA, Holt J, Wu XD, Mays JP. Characterization of a recombinant outer surface protein A (OspA) vaccine against Lyme disease. Dev Biol (Basel) 2001; 103:163-73. [PMID: 11214234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Lyme disease, the most prevalent tick-borne disease in the United States, results from infection with Borrelia burgdorferi sensu stricto. Early studies of Borrelia burgdorferi sensu stricto identified outer surface protein A (OspA), a lipoprotein on the surface of spirochetes that could be the target of protective antibodies to this agent. Pasteur Mérieux Connaught has developed a Lyme vaccine, ImuLyme, using recombinant OspA protein (rOspA). Methods were developed to routinely assess the identity, quantity, structure, purity, biological activity, heterogeneity, stability, and potency of rOspA. In addition, several methods were performed on a series of lots to support the routine testing methods and further our understanding of the physicochemical characteristics of rOspA. These tests were electrospray mass spectrometry, circular dichroism, two-dimensional gel electrophoresis, amino acid analysis, peptide mapping with peptide sequencing, and the application of proteomic methodology to identify trace contaminant host cell proteins. The results of these methods indicate that the rOspA lots are composed of highly purified and properly processed and folded rOspA with trace amounts of E. coli host cell proteins.
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Affiliation(s)
- R C Huebner
- Pasteur Mérieux Connaught, Swiftwater, PA 18370-0187, USA
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Stewart GS, Glanville M, Aziz O, Simmons NL, Gray MA. Regulation of an outwardly rectifying chloride conductance in renal epithelial cells by external and internal calcium. J Membr Biol 2001; 180:49-64. [PMID: 11284203 DOI: 10.1007/s002320010058] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have used perforated patch clamp and Fura-2 microfluorescence measurements to study Ca(2+)-activated Cl- currents in cultured mouse renal inner medullary collecting duct cells (mIMCD-3). The conductance was spontaneously active under resting conditions and whole cell currents were time and voltage-independent with an outwardly rectifying current-voltage relationship. The channel blockers DIDS, niflumic acid, glybenclamide and NPPB reversibly decreased the basal currents, whereas the sulfhydryl agent, DTT produced an irreversible inhibition. Increasing or decreasing extracellular calcium produced parallel changes in the size of the basal currents. Variations in external Ca2+ were associated with corresponding changes in free cytosolic Ca2+ concentration. Increasing cytosolic Ca2+ by extracellular ATP or ionomycin, further enhanced Cl- conductance, with whole cell currents displaying identical biophysical properties to the basal currents. However, the agonist-stimulated currents were now increased by DTT exposure, but still inhibited by the other channel blockers. Using RT-PCR, three distinct mRNA transcripts belonging to the CLCA family of Ca(2+)-activated Cl- channel proteins were identified, two of which represent novel sequences. Whether different channels underlie the basal and agonist-stimulated currents in mIMCD-3 cells is unclear. Our findings establish a novel link between alterations in external and internal Ca2+ and the activity of Ca(2+)-activated Cl- transport in these cells.
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Affiliation(s)
- G S Stewart
- Department of Physiological Sciences, University Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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Abstract
Parker and Carlisle (Journal of Advanced Nursing 24, 771-778) argue that there is a scarcity of empirical research focusing on issues such as supernumerary status and mentorship in Project 2000 courses from the students' perspective. This paper presents the findings of a longitudinal cohort study using Grounded Theory to discover the effect(s) of mentorship on student nurses following the introduction of the 1992 programme of education leading to a Diploma of Higher Education in Nursing and registration with the United Kingdom Central Council (UKCC). The cohort consisted of 10 students from a large Scottish College of Nursing & Midwifery who were interviewed on five occasions during the three years of their course. Students also kept a diary to record their thoughts and experiences regarding mentorship during their practice placements. In addition, a further seven students volunteered to participate by diary only. Data were analysed with the aid of NUD.IST and subjected to the constant comparative method of analysis. Findings indicate that Diploma students quickly lose their idealistic view of their mentor and over time develop an insight into the qualities they perceive are required of an effective mentor. Students quickly become aware of the importance of choosing good role models and learning their own mentor's likes and dislikes as they realize this impinges on the outcome of their assessment. As students move into their Branch programme, a gradual distancing from their mentor is evident. This coincides with a development in their confidence, skills and a holistic perspective of care.
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Affiliation(s)
- M A Gray
- Head of Department, Faculty of Health and Life Sciences, Napier University, Edinburgh, Scotland.
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