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Ledwos N, Rodas JD, Husain MI, Feusner JD, Castle DJ. Therapeutic uses of psychedelics for eating disorders and body dysmorphic disorder. J Psychopharmacol 2023; 37:3-13. [PMID: 36515406 DOI: 10.1177/02698811221140009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Clinical use of psychedelics has gained considerable attention, with promising benefits across a range of mental disorders. Current pharmacological and psychotherapeutic treatments for body dysmorphic disorder (BDD) and eating disorders (EDs) have limited efficacy. As such, other treatment options such as psychedelic-assisted therapies are being explored in these clinical groups. AIMS This systematic review evaluates evidence related to the therapeutic potential of psychedelics in individuals diagnosed with BDD and EDs. METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic review of all study designs published to the end of February 2022 that identified changes in ED/BDD symptom severity from psychedelics using validated measures to assess symptom changes. RESULTS Our search detected a total of 372 studies, of which five met inclusion criteria (two exploratory studies, two case reports, and one prospective study). These were included in the data evaluation. Effects of psychedelics on BDD and various ED symptoms were identified mostly through thematic analyses and self-reports. CONCLUSIONS Our findings highlight that more research is needed to determine the safety and efficacy of psychedelics in BDD and EDs and we suggest avenues for future exploration.
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Affiliation(s)
- Nicole Ledwos
- Centre for Complex Interventions, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Justyne D Rodas
- Centre for Complex Interventions, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - M Ishrat Husain
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Jamie D Feusner
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - David J Castle
- Centre for Complex Interventions, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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2
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Jalal B. "Men Fear Most What They Cannot See." sleep paralysis "Ghost Intruders" and faceless "Shadow-People"-The role of the right hemisphere and economizing nature of vision. Med Hypotheses 2021; 148:110521. [PMID: 33573871 DOI: 10.1016/j.mehy.2021.110521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/17/2021] [Accepted: 01/25/2021] [Indexed: 11/26/2022]
Abstract
Sleep paralysis is a curious condition where the paralyzed person may hallucinate terrifying ghosts. These hypnogogic and hypnopompic visions are common worldwide. They often entail seeing and sensing shadow beings; although hallucinating full-fledged figures (e.g., cat-like creatures and witches) are not uncommon. In this paper, I propose a neuroscientific account (building on previous work) for why people see ghosts during sleep paralysis and why these tend to manifest as faceless shadows. This novel venture considers the distinct computational styles of the right and left hemisphere and their functional specializations vis-à-vis florid intruder hallucinations and out-of-body experiences (OBEs) during these dream-like states. Additionally, I provide a brain-based explanation for dissociative phenomena common during sleep paralysis. Specifically, I posit that these ghost hallucinations and OBEs are chiefly mediated by activity in key regions in the right hemisphere; and outline how the functional organization of the visual system (evoking concepts like surface interpolation) and its economizing nature (i.e., proclivity to minimize computational load and take short-cuts) can explain faceless humanoid-shadows and sensed presence hallucinations during sleep paralysis; and how the hypothalamus and anterior cingulate may be implicated during related dissociative states. Ultimately empirical research must shed light on the validity of this account. If this hypothesis is correct, patients with right hemisphere damage (i.e., in implicated areas) should be less likely to hallucinate ghosts during sleep paralysis; i.e., compared to those with intact hemispheres or damage to the left only. It may also be possible to temporarily disable right hemisphere functions during sleep paralysis using transcranial magnetic stimulation. Accordingly, this procedure should eradicate sleep paralysis ghost hallucinations.
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Affiliation(s)
- Baland Jalal
- Harvard University, USA; University of Cambridge, UK.
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3
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Coenen HH, Ermert J. Expanding PET-applications in life sciences with positron-emitters beyond fluorine-18. Nucl Med Biol 2020; 92:241-269. [PMID: 32900582 DOI: 10.1016/j.nucmedbio.2020.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
Abstract
Positron-emission-tomography (PET) has become an indispensable diagnostic tool in modern nuclear medicine. Its outstanding molecular imaging features allow repetitive studies on one individual and with high sensitivity, though no interference. Rather few positron-emitters with near favourable physical properties, i.e. carbon-11 and fluorine-18, furnished most studies in the beginning, preferably if covalently bound as isotopic label of small molecules. With the advancement of PET-devices the scope of in vivo research in life sciences and especially that of medical applications expanded, and other than "standard" PET-nuclides received increasing significance, like the radiometals copper-64 and gallium-68. Especially during the last decades, positron-emitters of other chemical elements have gotten into the focus of interest, concomitant with the technical advancements in imaging and radionuclide production. With known nuclear imaging properties and main production methods of emerging positron-emitters their usefulness for medical application is promising and even proven for several ones already. Unfortunate decay properties could be corrected for, and β+-emitters, especially with a longer half-life, provided new possibilities for application where slower processes are of importance. Further on, (bio)chemical features of positron-emitters of other elements, among there many metals, not only expanded the field of classical clinical investigations, but also opened up new fields of application. Appropriately labelled peptides, proteins and nanoparticles lend itself as newer probes for PET-imaging, e.g. in theragnostic or PET/MR hybrid imaging. Furthermore, the potential of non-destructive in-vivo imaging with positron-emission-tomography directs the view on further areas of life sciences. Thus, exploiting the excellent methodology for basic research on molecular biochemical functions and processes is increasingly encouraged as well in areas outside of health, such as plant and environmental sciences.
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Affiliation(s)
- Heinz H Coenen
- Institut für Neurowissenschaften und Medizin, INM-5, Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
| | - Johannes Ermert
- Institut für Neurowissenschaften und Medizin, INM-5, Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
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Phi Van VD, Krause ET, Phi-Van L. Modulation of Fear and Arousal Behavior by Serotonin Transporter (5-HTT) Genotypes in Newly Hatched Chickens. Front Behav Neurosci 2018; 12:284. [PMID: 30524254 PMCID: PMC6256247 DOI: 10.3389/fnbeh.2018.00284] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 11/05/2018] [Indexed: 12/20/2022] Open
Abstract
The serotonin transporter (5-HTT) plays a key role in regulating serotonergic transmission via removal of serotonin (5-hydroxytryptamine, 5-HT) from synaptic clefts. Alterations in 5-HTT expression and 5-HT transmission have been shown to cause changes to adult behavior including fear. The objective of the present study was to investigate the 5-HTT role in fear in birds at the very early stages of post-hatching life. Using an avoidance test with an elevated balance beam, which was based on depth perception and the respective fear of heights, we assessed fear-related avoidance behaviors of newly hatched chicks of the three functional 5-HTT genotypes W/W, W/D and D/D. Newly hatched chicks of the genotype D/D, which was linked to high 5-HTT expression, showed less intensive avoidance responses as measured by decreased latency to jump than W/W and W/D chicks. Further, significantly fewer D/D hens than W/W hens showed fear-like behavior that resembled a freezing response. Furthermore, in an arousal test the arousal reaction of the chicks in response to an acute short-term visual social deprivation in the home compartment was assessed 5 weeks after hatching, which also revealed that D/D chicks exhibited decreased arousal reaction, compared to W/W chicks. Thus, the results indicate that fear responses differ in D/D chicks in the early post-hatching periods, possibly due to the different expression of 5-HTT respectively 5-HT levels in this strain.
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Affiliation(s)
- Valerie D Phi Van
- Institute of Diagnostic and Interventional Radiology, University Hospital Zürich, Zürich, Switzerland
| | - E Tobias Krause
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut (FLI), Celle, Germany
| | - Loc Phi-Van
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut (FLI), Celle, Germany
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Jalal B. The neuropharmacology of sleep paralysis hallucinations: serotonin 2A activation and a novel therapeutic drug. Psychopharmacology (Berl) 2018; 235:3083-3091. [PMID: 30288594 PMCID: PMC6208952 DOI: 10.1007/s00213-018-5042-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/17/2018] [Indexed: 12/21/2022]
Abstract
Sleep paralysis is a state of involuntary immobility occurring at sleep onset or offset, often accompanied by uncanny "ghost-like" hallucinations and extreme fear reactions. I provide here a neuropharmacological account for these hallucinatory experiences by evoking the role of the serotonin 2A receptor (5-HT2AR). Research has shown that 5-HT2AR activation can induce visual hallucinations, "mystical" subjective states, and out-of-body experiences (OBEs), and modulate fear circuits. Hallucinatory experiences triggered by serotonin-serotonergic ("pseudo") hallucinations, induced by hallucinogenic drugs-tend to be "dream-like" with the experiencer having insight ("meta-awareness") that he is hallucinating, unlike dopaminergic ("psychotic" and "life-like") hallucinations where such insight is lost. Indeed, hallucinatory experiences during sleep paralysis have the classic features of serotonergic hallucinations, and are strikingly similar to perceptual and subjective states induced by hallucinogenic drugs (e.g., lysergic acid diethylamide [LSD] and psilocybin), i.e., they entail visual hallucinations, mystical experiences, OBEs, and extreme fear reactions. I propose a possible mechanism whereby serotonin could be functionally implicated in generating sleep paralysis hallucinations and fear reactions through 5-HT2AR activity. Moreover, I speculate on the role of 5-HT2C receptors vis-à-vis anxiety and panic during sleep paralysis, and the orbitofrontal cortex-rich with 5-HT2A receptors-in influencing visual pathways during sleep paralysis, and, in effect, hallucinations. Finally, I propose, for the first time, a drug to target sleep paralysis hallucinations and fear reactions, namely the selective 5-HT2AR inverse agonist, pimavanserin. This account implicates gene HTR2A on chromosome 13q as the underlying cause of sleep paralysis hallucinations and could be explored using positron emission tomography.
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Affiliation(s)
- Baland Jalal
- Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
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Riga MS, Lladó-Pelfort L, Artigas F, Celada P. The serotonin hallucinogen 5-MeO-DMT alters cortico-thalamic activity in freely moving mice: Regionally-selective involvement of 5-HT 1A and 5-HT 2A receptors. Neuropharmacology 2017; 142:219-230. [PMID: 29221792 DOI: 10.1016/j.neuropharm.2017.11.049] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/21/2017] [Accepted: 11/30/2017] [Indexed: 01/26/2023]
Abstract
5-MeO-DMT is a natural hallucinogen acting as serotonin 5-HT1A/5-HT2A receptor agonist. Its ability to evoke hallucinations could be used to study the neurobiology of psychotic symptoms and to identify new treatment targets. Moreover, recent studies revealed the therapeutic potential of serotonin hallucinogens in treating mood and anxiety disorders. Our previous results in anesthetized animals show that 5-MeO-DMT alters cortical activity via 5-HT1A and 5-HT2A receptors. Here, we examined 5-MeO-DMT effects on oscillatory activity in prefrontal (PFC) and visual (V1) cortices, and in mediodorsal thalamus (MD) of freely-moving wild-type (WT) and 5-HT2A-R knockout (KO2A) mice. We performed local field potential multi-recordings evaluating the power at different frequency bands and coherence between areas. We also examined the prevention of 5-MeO-DMT effects by the 5-HT1A-R antagonist WAY-100635. 5-MeO-DMT affected oscillatory activity more in cortical than in thalamic areas. More marked effects were observed in delta power in V1 of KO2A mice. 5-MeO-DMT increased beta band coherence between all examined areas. In KO2A mice, WAY100635 prevented most of 5-MeO-DMT effects on oscillatory activity. The present results indicate that hallucinatory activity of 5-MeO-DMT is likely mediated by simultaneous alteration of prefrontal and visual activities. The prevention of these effects by WAY-100635 in KO2A mice supports the potential usefulness of 5-HT1A receptor antagonists to treat visual hallucinations. 5-MeO-DMT effects on PFC theta activity and cortico-thalamic coherence may be related to its antidepressant activity. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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Affiliation(s)
- Maurizio S Riga
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC-IDIBAPS, Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain
| | - Laia Lladó-Pelfort
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC-IDIBAPS, Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain
| | - Francesc Artigas
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC-IDIBAPS, Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain
| | - Pau Celada
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC-IDIBAPS, Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.
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7
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Njemanze PC, Kranz M, Amend M, Hauser J, Wehrl H, Brust P. Gender differences in cerebral metabolism for color processing in mice: A PET/MRI Study. PLoS One 2017; 12:e0179919. [PMID: 28723938 PMCID: PMC5516971 DOI: 10.1371/journal.pone.0179919] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 06/06/2017] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Color processing is a central component of mammalian vision. Gender-related differences of color processing revealed by non-invasive functional transcranial Doppler ultrasound suggested right hemisphere pattern for blue/yellow chromatic opponency by men, and a left hemisphere pattern by women. MATERIALS AND METHODS The present study measured the accumulation of [18F]fluorodeoxyglucose ([18F]FDG) in mouse brain using small animal positron emission tomography and magnetic resonance imaging (PET/MRI) with statistical parametric mapping (SPM) during light stimulation with blue and yellow filters compared to darkness condition. RESULTS PET revealed a reverse pattern relative to dark condition compared to previous human studies: Male mice presented with left visual cortex dominance for blue through the right eye, while female mice presented with right visual cortex dominance for blue through the left eye. We applied statistical parametric mapping (SPM) to examine gender differences in activated architectonic areas within the orbital and medial prefrontal cortex and related cortical and sub-cortical areas that lead to the striatum, medial thalamus and other brain areas. The metabolic connectivity of the orbital and medial prefrontal cortex evoked by blue stimulation spread through a wide range of brain structures implicated in viscerosensory and visceromotor systems in the left intra-hemispheric regions in male, but in the right-to-left inter-hemispheric regions in female mice. Color functional ocular dominance plasticity was noted in the right eye in male mice but in the left eye in female mice. CONCLUSIONS This study of color processing in an animal model could be applied in the study of the role of gender differences in brain disease.
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Affiliation(s)
- Philip C. Njemanze
- Chidicon Medical Center, Neurocybernetic Flow Laboratory, International Institutes of Advanced Research Training, Owerri, Imo State, Nigeria
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden—Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Leipzig, Germany
| | - Mario Amend
- Eberhard Karls University Tübingen, Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Tübingen, Germany
| | - Jens Hauser
- Helmholtz-Zentrum Dresden—Rossendorf, Department of Mechanical Engineering Dresden, Germany
| | - Hans Wehrl
- Eberhard Karls University Tübingen, Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Tübingen, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden—Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Leipzig, Germany
- * E-mail:
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8
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Chilla SNM, Henoumont C, Elst LV, Muller RN, Laurent S. Importance of DOTA derivatives in bimodal imaging. Isr J Chem 2017. [DOI: 10.1002/ijch.201700024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
| | - Céline Henoumont
- General Organic and Biomedical chemistry University of Mons; Avenue Victor Maistriau, 19 7000 Mons Belgium
| | - Luce Vander Elst
- General Organic and Biomedical chemistry University of Mons; Avenue Victor Maistriau, 19 7000 Mons Belgium
| | - Robert N. Muller
- General Organic and Biomedical chemistry University of Mons; Avenue Victor Maistriau, 19 7000 Mons Belgium
- Center for Microscopy and Molecular Imaging (CMMI); Institution Rue Adrienne Bolland 8 Gosselies 6041 Belgium
| | - Sophie Laurent
- General Organic and Biomedical chemistry University of Mons; Avenue Victor Maistriau, 19 7000 Mons Belgium
- Center for Microscopy and Molecular Imaging (CMMI); Institution Rue Adrienne Bolland 8 Gosselies 6041 Belgium
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9
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Zhang G, Cinalli D, Stackman RW. Effect of a hallucinogenic serotonin 5‐HT
2A
receptor agonist on visually guided, hippocampal‐dependent spatial cognition in C57BL/6J mice. Hippocampus 2017; 27:558-569. [DOI: 10.1002/hipo.22712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Gongliang Zhang
- Department of PharmacologySchool of Basic Medical Sciences, Anhui Medical UniversityHefei Anhui China
- Jupiter Life Science InitiativeFlorida Atlantic UniversityJupiter Florida
| | - David Cinalli
- Department of PsychologyCharles E. Schmidt College of Science, Florida Atlantic UniversityJupiter Florida
| | - Robert W. Stackman
- Jupiter Life Science InitiativeFlorida Atlantic UniversityJupiter Florida
- Department of PsychologyCharles E. Schmidt College of Science, Florida Atlantic UniversityJupiter Florida
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Valle M, Maqueda AE, Rabella M, Rodríguez-Pujadas A, Antonijoan RM, Romero S, Alonso JF, Mañanas MÀ, Barker S, Friedlander P, Feilding A, Riba J. Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans. Eur Neuropsychopharmacol 2016; 26:1161-75. [PMID: 27039035 DOI: 10.1016/j.euroneuro.2016.03.012] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 03/02/2016] [Accepted: 03/19/2016] [Indexed: 12/11/2022]
Abstract
Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus β-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans.
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Affiliation(s)
- Marta Valle
- Pharmacokinetic and Pharmacodynamic Modelling and Simulation, IIB Sant Pau, Sant Antoni María Claret, 167, 08025 Barcelona, Spain; Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Sant Antoni María Claret, 167, 08025 Barcelona, Spain; Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain
| | - Ana Elda Maqueda
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Human Neuropsychopharmacology Research Group. Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret, 167, 08025 Barcelona, Spain
| | - Mireia Rabella
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Servei de Psiquiatria, Hospital de la Santa Creu i Sant Pau, Sant Antoni María Claret, 167, 08025 Barcelona, Spain
| | - Aina Rodríguez-Pujadas
- Human Neuropsychopharmacology Research Group. Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret, 167, 08025 Barcelona, Spain
| | - Rosa Maria Antonijoan
- Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Sant Antoni María Claret, 167, 08025 Barcelona, Spain; Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain
| | - Sergio Romero
- Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain
| | - Joan Francesc Alonso
- Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain; Barcelona College of Industrial Engineering (EUETIB), UniversitatPolitècnica de Catalunya (UPC), Barcelona 08028, Spain
| | - Miquel Àngel Mañanas
- Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain; Barcelona College of Industrial Engineering (EUETIB), UniversitatPolitècnica de Catalunya (UPC), Barcelona 08028, Spain
| | - Steven Barker
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive at River Road, Baton Rouge, LA 70803, USA
| | - Pablo Friedlander
- The Beckley Foundation, Beckley Park, Oxford OX3 9SY, United Kingdom
| | - Amanda Feilding
- The Beckley Foundation, Beckley Park, Oxford OX3 9SY, United Kingdom
| | - Jordi Riba
- Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Sant Antoni María Claret, 167, 08025 Barcelona, Spain; Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain; Human Neuropsychopharmacology Research Group. Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret, 167, 08025 Barcelona, Spain.
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Burke BP, Baghdadi N, Kownacka AE, Nigam S, Clemente GS, Al-Yassiry MM, Domarkas J, Lorch M, Pickles M, Gibbs P, Tripier R, Cawthorne C, Archibald SJ. Chelator free gallium-68 radiolabelling of silica coated iron oxide nanorods via surface interactions. NANOSCALE 2015; 7:14889-14896. [PMID: 26292197 DOI: 10.1039/c5nr02753e] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The commercial availability of combined magnetic resonance imaging (MRI)/positron emission tomography (PET) scanners for clinical use has increased demand for easily prepared agents which offer signal or contrast in both modalities. Herein we describe a new class of silica coated iron-oxide nanorods (NRs) coated with polyethylene glycol (PEG) and/or a tetraazamacrocyclic chelator (DO3A). Studies of the coated NRs validate their composition and confirm their properties as in vivo T2 MRI contrast agents. Radiolabelling studies with the positron emitting radioisotope gallium-68 (t1/2 = 68 min) demonstrate that, in the presence of the silica coating, the macrocyclic chelator was not required for preparation of highly stable radiometal-NR constructs. In vivo PET-CT and MR imaging studies show the expected high liver uptake of gallium-68 radiolabelled nanorods with no significant release of gallium-68 metal ions, validating our innovation to provide a novel simple method for labelling of iron oxide NRs with a radiometal in the absence of a chelating unit that can be used for high sensitivity liver imaging.
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Affiliation(s)
- Benjamin P Burke
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
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Burke BP, Baghdadi N, Clemente GS, Camus N, Guillou A, Kownacka AE, Domarkas J, Halime Z, Tripier R, Archibald SJ. Final step gallium-68 radiolabelling of silica-coated iron oxide nanorods as potential PET/MR multimodal imaging agents. Faraday Discuss 2015; 175:59-71. [PMID: 25325197 DOI: 10.1039/c4fd00137k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The investigation of iron oxide-based positron emission tomography/magnetic resonance (PET/MR) multimodal imaging agents is an expanding field in which a variety of nanoparticle sizes, shapes, surface coatings and radioisotopes are open for exploration. This study develops iron oxide nanorods which are coated with various mixtures of poly(ethylene glycol) (PEG) and macrocyclic ligand (DO3A) via the formation of a silica layer on the surface. Gallium-68 radiolabelling of the nanorods was carried out in high radiochemical yields (RCY) and their stability in human serum was demonstrated for all constructs, even in the absence of the macrocyclic chelating unit. Further studies were carried out in an attempt to determine the appropriate amount of PEG coating to give optimal properties for future in vivo studies.
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Affiliation(s)
- Benjamin P Burke
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
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13
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White C, Edwards M, Brown J, Bell J. The impact of recreational MDMA 'ecstasy' use on global form processing. J Psychopharmacol 2014; 28:1018-29. [PMID: 25142406 DOI: 10.1177/0269881114546709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability to integrate local orientation information into a global form percept was investigated in long-term ecstasy users. Evidence suggests that ecstasy disrupts the serotonin system, with the visual areas of the brain being particularly susceptible. Previous research has found altered orientation processing in the primary visual area (V1) of users, thought to be due to disrupted serotonin-mediated lateral inhibition. The current study aimed to investigate whether orientation deficits extend to higher visual areas involved in global form processing. Forty-five participants completed a psychophysical (Glass pattern) study allowing an investigation into the mechanisms underlying global form processing and sensitivity to changes in the offset of the stimuli (jitter). A subgroup of polydrug-ecstasy users (n=6) with high ecstasy use had significantly higher thresholds for the detection of Glass patterns than controls (n=21, p=0.039) after Bonferroni correction. There was also a significant interaction between jitter level and drug-group, with polydrug-ecstasy users showing reduced sensitivity to alterations in jitter level (p=0.003). These results extend previous research, suggesting disrupted global form processing and reduced sensitivity to orientation jitter with ecstasy use. Further research is needed to investigate this finding in a larger sample of heavy ecstasy users and to differentiate the effects of other drugs.
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Affiliation(s)
- Claire White
- The Australian National University, Canberra, ACT, Australia
| | - Mark Edwards
- The Australian National University, Canberra, ACT, Australia
| | - John Brown
- The Australian National University, Canberra, ACT, Australia
| | - Jason Bell
- The University of Western Australia, Perth, WA, Australia
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Varvatsoulias G. The Physiological Processes Underpinning PET and fMRI Techniques With an Emphasis on the Temporal and Spatial Resolution of These Methods. PSYCHOLOGICAL THOUGHT 2013. [DOI: 10.5964/psyct.v6i2.75] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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15
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Activation of serotonin 2A receptors underlies the psilocybin-induced effects on α oscillations, N170 visual-evoked potentials, and visual hallucinations. J Neurosci 2013; 33:10544-51. [PMID: 23785166 DOI: 10.1523/jneurosci.3007-12.2013] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Visual illusions and hallucinations are hallmarks of serotonergic hallucinogen-induced altered states of consciousness. Although the serotonergic hallucinogen psilocybin activates multiple serotonin (5-HT) receptors, recent evidence suggests that activation of 5-HT2A receptors may lead to the formation of visual hallucinations by increasing cortical excitability and altering visual-evoked cortical responses. To address this hypothesis, we assessed the effects of psilocybin (215 μg/kg vs placebo) on both α oscillations that regulate cortical excitability and early visual-evoked P1 and N170 potentials in healthy human subjects. To further disentangle the specific contributions of 5-HT2A receptors, subjects were additionally pretreated with the preferential 5-HT2A receptor antagonist ketanserin (50 mg vs placebo). We found that psilocybin strongly decreased prestimulus parieto-occipital α power values, thus precluding a subsequent stimulus-induced α power decrease. Furthermore, psilocybin strongly decreased N170 potentials associated with the appearance of visual perceptual alterations, including visual hallucinations. All of these effects were blocked by pretreatment with the 5-HT2A antagonist ketanserin, indicating that activation of 5-HT2A receptors by psilocybin profoundly modulates the neurophysiological and phenomenological indices of visual processing. Specifically, activation of 5-HT2A receptors may induce a processing mode in which stimulus-driven cortical excitation is overwhelmed by spontaneous neuronal excitation through the modulation of α oscillations. Furthermore, the observed reduction of N170 visual-evoked potentials may be a key mechanism underlying 5-HT2A receptor-mediated visual hallucinations. This change in N170 potentials may be important not only for psilocybin-induced states but also for understanding acute hallucinatory states seen in psychiatric disorders, such as schizophrenia and Parkinson's disease.
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Li A, Zheng Y, Yu J, Wang Z, Yang Y, Wu W, Guo D, Ran H. Superparamagnetic perfluorooctylbromide nanoparticles as a multimodal contrast agent for US, MR, and CT imaging. Acta Radiol 2013; 54:278-83. [PMID: 23319724 DOI: 10.1258/ar.2012.120130] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Multimodal contrast agents usually containing two or more signal components can be used for several imaging modalities. Thus, complimentary information can be obtained by using just one kind of contrast agents. PURPOSE To investigate the potential of superparamagnetic perfluorooctylbromide nanoparticles (M-PFOBNP) as a multimodal contrast agent for ultrasonography (US)/magnetic resonance (MR)/computed tomography (CT) multimodality imaging. MATERIAL AND METHODS The composite agent M-PFOBNP was developed by introducing superparamagnetic Fe3O4 nanoparticles into perfluorooctylbromide nanoparticles (PFOBNP). Several analytical tools were employed to characterize the agent. The potential of M-PFOBNP for US/MR/CT multimodality imaging were assessed in vivo. The cellular uptake and cytotoxicity of the agent were studied in vitro. RESULTS M-PFOBNP with well-defined spherical morphology and homogeneous size of 200-250 nm was obtained. Fe3O4 nanoparticles were successfully integrated into PFOBNP and preserved their superparamagnetic characteristics after encapsulation. The in vivo studies showed that M-PFOBNP produced higher echogenicity than PFOBNP and possessed strong magnetic susceptibility and radiopacity for multimodality imaging. Macrophages incubated with different concentrations of M-PFOBNP resulted in a dose-dependent cellular uptake, which did not affect the viability of the cells. CONCLUSION M-PFOBNP may potentially serve as a multimodal contrast agent for enhanced US, MR, and CT imaging.
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Affiliation(s)
- Ao Li
- Department of Ultrasound in Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing
| | - Yuanyi Zheng
- Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Jinhong Yu
- Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Zhigang Wang
- Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Yang Yang
- Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Wei Wu
- Department of Radiology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dajing Guo
- Department of Radiology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Haitao Ran
- Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
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Savli M, Bauer A, Mitterhauser M, Ding YS, Hahn A, Kroll T, Neumeister A, Haeusler D, Ungersboeck J, Henry S, Isfahani SA, Rattay F, Wadsak W, Kasper S, Lanzenberger R. Normative database of the serotonergic system in healthy subjects using multi-tracer PET. Neuroimage 2012; 63:447-59. [PMID: 22789740 DOI: 10.1016/j.neuroimage.2012.07.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 06/28/2012] [Accepted: 07/02/2012] [Indexed: 01/13/2023] Open
Abstract
The highly diverse serotonergic system with at least 16 different receptor subtypes is implicated in the pathophysiology of most neuropsychiatric disorders including affective and anxiety disorders, obsessive compulsive disorder, post-traumatic stress disorder, eating disorders, sleep disturbance, attention deficit/hyperactivity disorder, drug addiction, suicidal behavior, schizophrenia, Alzheimer, etc. Alterations of the interplay between various pre- and postsynaptic receptor subtypes might be involved in the pathogenesis of these disorders. However, there is a lack of comprehensive in vivo values using standardized procedures. In the current PET study we quantified 3 receptor subtypes, including the major inhibitory (5-HT(1A) and 5-HT(1B)) and excitatory (5-HT(2A)) receptors, and the transporter (5-HTT) in the brain of healthy human subjects to provide a database of standard values. PET scans were performed on 95 healthy subjects (age=28.0 ± 6.9 years; 59% males) using the selective radioligands [carbonyl-(11)C]WAY-100635, [(11)C]P943, [(18)F]altanserin and [(11)C]DASB, respectively. A standard template in MNI stereotactic space served for region of interest delineation. This template follows two anatomical parcellation schemes: 1) Brodmann areas including 41 regions and 2) AAL (automated anatomical labeling) including 52 regions. Standard values (mean, SD, and range) for each receptor and region are presented. Mean cortical and subcortical binding potential (BP) values were in good agreement with previously published human in vivo and post-mortem data. By means of linear equations, PET binding potentials were translated to post-mortem binding (provided in pmol/g), yielding 5.89 pmol/g (5-HT(1A)), 23.5 pmol/g (5-HT(1B)), 31.44 pmol/g (5-HT(2A)), and 11.33 pmol/g (5-HTT) being equivalent to the BP of 1, respectively. Furthermore, we computed individual voxel-wise maps with BP values and generated average tracer-specific whole-brain binding maps. This knowledge might improve our interpretation of the alterations taking place in the serotonergic system during neuropsychiatric disorders.
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Affiliation(s)
- Markus Savli
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
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18
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Brown TT, Jernigan TL. Brain development during the preschool years. Neuropsychol Rev 2012; 22:313-33. [PMID: 23007644 DOI: 10.1007/s11065-012-9214-1] [Citation(s) in RCA: 192] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/13/2012] [Indexed: 01/16/2023]
Abstract
The preschool years represent a time of expansive mental growth, with the initial expression of many psychological abilities that will continue to be refined into young adulthood. Likewise, brain development during this age is characterized by its "blossoming" nature, showing some of its most dynamic and elaborative anatomical and physiological changes. In this article, we review human brain development during the preschool years, sampling scientific evidence from a variety of sources. First, we cover neurobiological foundations of early postnatal development, explaining some of the primary mechanisms seen at a larger scale within neuroimaging studies. Next, we review evidence from both structural and functional imaging studies, which now accounts for a large portion of our current understanding of typical brain development. Within anatomical imaging, we focus on studies of developing brain morphology and tissue properties, including diffusivity of white matter fiber tracts. We also present new data on changes during the preschool years in cortical area, thickness, and volume. Physiological brain development is then reviewed, touching on influential results from several different functional imaging and recording modalities in the preschool and early school-age years, including positron emission tomography (PET), electroencephalography (EEG) and event-related potentials (ERP), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and near-infrared spectroscopy (NIRS). Here, more space is devoted to explaining some of the key methodological factors that are required for interpretation. We end with a section on multimodal and multidimensional imaging approaches, which we believe will be critical for increasing our understanding of brain development and its relationship to cognitive and behavioral growth in the preschool years and beyond.
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Affiliation(s)
- Timothy T Brown
- Multimodal Imaging Laboratory, University of California-San Diego, La Jolla, CA 92093, USA.
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Murray E, Bruno R, Brown J. Residual effects of ecstasy (3,4-methylenedioxymethamphetamine) on low level visual processes. Hum Psychopharmacol 2012; 27:226-34. [PMID: 22389087 DOI: 10.1002/hup.2218] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
'Ecstasy' (3,4-methylenedioxymethamphetamine) induces impaired functioning in the serotonergic system, including the occipital lobe. This study employed the 'tilt aftereffect' paradigm to operationalise the function of orientation-selective neurons among ecstasy consumers and controls as a means of investigating the role of reduced serotonin on visual orientation processing. The magnitude of the tilt aftereffect reflects the extent of lateral inhibition between orientation-selective neurons and is elicited to both 'real' contours, processed in visual cortex area V1, and illusory contours, processed in V2. The magnitude of tilt aftereffect to both contour types was examined among 19 ecstasy users (6 ecstasy only; 13 ecstasy-plus-cannabis users) and 23 matched controls (9 cannabis-only users; 14 drug-naive). Ecstasy users had a significantly greater tilt magnitude than non-users for real contours (Hedge's g = 0.63) but not for illusory contours (g = 0.20). These findings provide support for literature suggesting that residual effects of ecstasy (and reduced serotonin) impairs lateral inhibition between orientation-selective neurons in V1, which however suggests that ecstasy may not substantially affect this process in V2. Multiple studies have now demonstrated ecstasy-related deficits on basic visual functions, including orientation and motion processing. Such low-level effects may contribute to the impact of ecstasy use on neuropsychological tests of visuospatial function.
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Saulin A, Savli M, Lanzenberger R. Serotonin and molecular neuroimaging in humans using PET. Amino Acids 2011; 42:2039-57. [PMID: 21947614 DOI: 10.1007/s00726-011-1078-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 09/05/2011] [Indexed: 02/07/2023]
Abstract
The serotonergic system is one of the most important modulatory neurotransmitter systems in the human brain. It plays a central role in major physiological processes and is implicated in a number of psychiatric disorders. Along with the dopaminergic system, it is also one of the phylogenetically oldest human neurotransmitter systems and one of the most diverse, with 14 different receptors identified up to this day, many of whose function remains to be understood. The system's functioning is even more diverse than the number of its receptors, since each is implicated in a number of different processes. This review aims at illustrating the distribution and summarizing the main functions of the serotonin (5-hydroxytryptamin, 5-HT) receptors as well as the serotonin transporter (SERT, 5-HTT), the vesicular monoamine transporter 2, monoamine oxidase type A and 5-HT synthesis in the human brain. Recent advances in in vivo quantification of these different receptors and enzymes that are part of the serotonergic system using positron emission tomography are described.
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Affiliation(s)
- Anne Saulin
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
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21
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The 5-HT2A/1A agonist psilocybin disrupts modal object completion associated with visual hallucinations. Biol Psychiatry 2011; 69:399-406. [PMID: 21126732 DOI: 10.1016/j.biopsych.2010.10.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 10/04/2010] [Accepted: 10/05/2010] [Indexed: 11/21/2022]
Abstract
BACKGROUND Recent findings suggest that the serotonergic system and particularly the 5-HT2A/1A receptors are implicated in visual processing and possibly the pathophysiology of visual disturbances including hallucinations in schizophrenia and Parkinson's disease. METHODS To investigate the role of 5-HT2A/1A receptors in visual processing the effect of the hallucinogenic 5-HT2A/1A agonist psilocybin (125 and 250 μg/kg vs. placebo) on the spatiotemporal dynamics of modal object completion was assessed in normal volunteers (n = 17) using visual evoked potential recordings in conjunction with topographic-mapping and source analysis. These effects were then considered in relation to the subjective intensity of psilocybin-induced visual hallucinations quantified by psychometric measurement. RESULTS Psilocybin dose-dependently decreased the N170 and, in contrast, slightly enhanced the P1 component selectively over occipital electrode sites. The decrease of the N170 was most apparent during the processing of incomplete object figures. Moreover, during the time period of the N170, the overall reduction of the activation in the right extrastriate and posterior parietal areas correlated positively with the intensity of visual hallucinations. CONCLUSIONS These results suggest a central role of the 5-HT2A/1A-receptors in the modulation of visual processing. Specifically, a reduced N170 component was identified as potentially reflecting a key process of 5-HT2A/1A receptor-mediated visual hallucinations and aberrant modal object completion potential.
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Area-specific modulation of neural activation comparing escitalopram and citalopram revealed by pharmaco-fMRI: a randomized cross-over study. Neuroimage 2009; 49:1161-70. [PMID: 19833214 DOI: 10.1016/j.neuroimage.2009.10.013] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/30/2009] [Accepted: 10/06/2009] [Indexed: 11/21/2022] Open
Abstract
Area-specific and stimulation-dependent changes of human brain activation by selective serotonin reuptake inhibitors (SSRI) are an important issue for improved understanding of treatment mechanisms, given the frequent prescription of these drugs in depression and anxiety disorders. The aim of this neuroimaging study was to investigate differences in BOLD-signal caused by administration of the SSRIs escitalopram and citalopram using pharmacological functional magnetic resonance imaging (pharmaco-fMRI). Eighteen healthy subjects participated in a placebo-controlled, randomized, double-blind study in cross-over repeated measures design. Each volunteer performed facial emotional discrimination and a sensorimotor control paradigm during three scanning sessions. Citalopram (20 mg/d), escitalopram (10 mg/d) and placebo were administered for 10 days each with a drug-free period of at least 21 days. Significant pharmacological effects on BOLD-signal were found in the amygdala, medial frontal gyrus, parahippocampal, fusiform and middle temporal gyri. Post-hoc t-tests revealed decreased BOLD-signal in the right amygdala and left parahippocampal gyrus in both pharmacological conditions, compared to placebo. Escitalopram, compared to citalopram, induced a decrease of BOLD-signal in the medial frontal gyrus and an increase in the right fusiform and left parahippocampal gyri. Drug effects were concentrated in brain regions with dense serotonergic projections. Both escitalopram and citalopram attenuated BOLD-signal in the amygdala and parahippocampal cortex to emotionally significant stimuli compared to control stimuli. We believe that reduced reactivity in the medial frontal gyrus found for escitalopram compared to citalopram administration might explain the response differences between study drugs as demonstrated in previous clinical trials.
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Witte AV, Flöel A, Stein P, Savli M, Mien LK, Wadsak W, Spindelegger C, Moser U, Fink M, Hahn A, Mitterhauser M, Kletter K, Kasper S, Lanzenberger R. Aggression is related to frontal serotonin-1A receptor distribution as revealed by PET in healthy subjects. Hum Brain Mapp 2009; 30:2558-70. [PMID: 19086022 DOI: 10.1002/hbm.20687] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVES Various studies indicate that serotonin regulates impulsivity and the inhibitory control of aggression. Aggression is also known to be modified by sex hormones, which exert influence on serotonergic neurotransmission. The present study aimed to elucidate potential interactions between human aggression, the inhibitory serotonergic 5-HT(1A) receptor, and sex hormones. EXPERIMENTAL DESIGN Thirty-three healthy volunteers (16 women, aged 26.24 +/- 5.5 yr) completed a validated questionnaire incorporating five dimensions of aggression. Subsequently, all subjects underwent positron emission tomography with the radioligand [carbonyl-(11)C]WAY-100635 to quantify 5-HT(1A) binding potentials (BP(ND)s) in the prefrontal cortex, limbic areas, and midbrain. Also, plasma levels of testosterone, 17beta-estradiol and sex hormone-binding globulin (SHBG) were measured. Relations between aggression scores, regional 5-HT(1A) BP(ND)s, and hormone levels were analyzed using correlations, multivariate analyses of variance, and linear regressions. PRINCIPAL OBSERVATIONS Statistical analyses revealed higher 5-HT(1A) receptor BP(ND)s in subjects exhibiting higher aggression scores in prefrontal (all P < 0.041) and anterior cingulate cortices (P = 0.016). More aggressive subjects were also characterized by lower SHBG levels (P = 0.015). Moreover, higher SHBG levels were associated with lower 5-HT(1A) BP(ND)s in frontal (P = 0.048) and cingulate cortices (all P < 0.013) and in the amygdala (P = 0.03). CONCLUSIONS The present study provides first-time evidence for a specific interrelation between the 5-HT(1A) receptor distribution, sex hormones, and aggression in humans. Our findings point to a reduced down-stream control due to higher amounts or activities of frontal 5-HT(1A) receptors in more aggressive subjects, which is presumably modulated by sex hormones.
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Affiliation(s)
- A Veronica Witte
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
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Abstract
INTRODUCTION Magnetic resonance (MR) methods are non-invasive techniques to provide detailed, multi-parametric information on human anatomy, function and metabolism. Sensitivity, specificity, spatial and temporal resolution may, however, vary depending on hardware (e.g., field strength, gradient strength and speed) and software (optimised measurement protocols and parameters for the various techniques). Furthermore, multi-modality imaging may enhance specificity to better characterise complex disease patterns. OBJECTIVE Positron emission tomography (PET) is an interesting, largely complementary modality, which might be combined with MR. Despite obvious advantages, combining these rather different physical methods may also pose challenging problems. At this early stage, it seems that PET quality may be preserved in the magnetic field and, if an adequate detector material is used for the PET, MR sensitivity should not be significantly degraded. Again, this may vary for the different MR techniques, whereby functional and metabolic MR is more susceptible than standard anatomical imaging. DISCUSSION Here we provide a short introduction to MR basics and MR techniques, also discussing advantages, artefacts and problems when MR hardware and PET detectors are combined. In addition to references for more detailed descriptions of MR fundamentals and applications, we provide an early outlook on this novel and exciting multi-modality approach to PET/MR.
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Kang E, Kim K, Kwon IC. Multifunctional Nanoparticles for Molecular Imaging. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2009. [DOI: 10.5124/jkma.2009.52.2.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Eunah Kang
- Biomedical Research Center, Korea Institute of Science & Technology, Korea. , ,
| | - Kwangmeyung Kim
- Biomedical Research Center, Korea Institute of Science & Technology, Korea. , ,
| | - Ick Chan Kwon
- Biomedical Research Center, Korea Institute of Science & Technology, Korea. , ,
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Jennings LE, Long NJ. ‘Two is better than one’—probes for dual-modality molecular imaging. Chem Commun (Camb) 2009:3511-24. [DOI: 10.1039/b821903f] [Citation(s) in RCA: 344] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Fink M, Wadsak W, Savli M, Stein P, Moser U, Hahn A, Mien LK, Kletter K, Mitterhauser M, Kasper S, Lanzenberger R. Lateralization of the serotonin-1A receptor distribution in language areas revealed by PET. Neuroimage 2008; 45:598-605. [PMID: 19103294 DOI: 10.1016/j.neuroimage.2008.11.033] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 10/06/2008] [Accepted: 11/12/2008] [Indexed: 11/28/2022] Open
Abstract
Lateralization is a well described aspect of the human brain. A plethora of morphological, cytological and functional studies describes hemispheric asymmetry in auditory and language areas. However, no study has reported cortical lateralization in the healthy human brain in vivo on the level of neurotransmitter receptors and in relation to functional organization so far. In this study, we assessed the distribution of the main inhibitory serotonergic receptor (the 5-HT1A receptor) and analyzed its regional binding with regard to hemisphere, sex and plasma levels of sex steroid hormones (testosterone, estradiol, progesterone). We quantified the 5-HT1A receptor binding potential by positron emission tomography (PET) using the highly selective and specific radioligand [carbonyl-11C]WAY-100635 and measured hormone levels in thirty-four (16 females, 18 males) healthy right-handed subjects. The obtained data were analyzed in an automated region of interest (ROI) based approach investigating 14 auditory, language and limbic areas. We found significantly higher 5-HT1A receptor binding in the superior and middle frontal gyri of the right hemisphere, the triangular and orbital parts of the inferior frontal gyrus, the supramarginal gyrus, the superior gyrus of the temporal pole and the middle temporal gyrus. Regions of the primary and secondary auditory cortex (Heschl's gyrus and superior temporal gyrus) and the Rolandic operculum displayed significantly higher receptor binding in the left hemisphere. 5-HT1A receptor binding was 1.8-2.9% higher in right frontal ROIs and 2-3.6% higher in left primary and secondary auditory regions. There was no hemispheric difference in 5-HT(1A) receptor binding in the hippocampus, amygdala, and insula. Post-hoc testing suggested that lateralization of 5-HT1A receptor binding differed between the sexes in the triangular part of the inferior frontal gyrus. For the first time, this PET study shows lateralization of the main inhibitory receptor of the serotonergic system in functionally asymmetric organized regions of the healthy human brain in vivo.
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Affiliation(s)
- Martin Fink
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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