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Constantin S, Jasoni C, Romanò N, Lee K, Herbison AE. Understanding calcium homeostasis in postnatal gonadotropin-releasing hormone neurons using cell-specific Pericam transgenics. Cell Calcium 2011; 51:267-76. [PMID: 22177387 DOI: 10.1016/j.ceca.2011.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 11/07/2011] [Accepted: 11/17/2011] [Indexed: 12/11/2022]
Abstract
The gonadotropin-releasing hormone (GnRH) neurons are the key output cells of a complex neuronal network controlling fertility in mammals. To examine calcium homeostasis in postnatal GnRH neurons, we generated a transgenic mouse line in which the genetically encodable calcium indicator ratiometric Pericam (rPericam) was targeted to the GnRH neurons. This mouse model enabled real-time imaging of calcium concentrations in GnRH neurons in the acute brain slice preparation. Investigations in GnRH-rPericam mice revealed that GnRH neurons exhibited spontaneous, long-duration (~8s) calcium transients. Dual electrical-calcium recordings revealed that the calcium transients were correlated perfectly with burst firing in GnRH neurons and that calcium transients in GnRH neurons regulated two calcium-activated potassium channels that, in turn, determined burst firing dynamics in these cells. Curiously, the occurrence of calcium transients in GnRH neurons across puberty or through the estrous cycle did not correlate well with the assumption that GnRH neuron burst firing was contributory to changing patterns of pulsatile GnRH release at these times. The GnRH-rPericam mouse was also valuable in determining differential mechanisms of GABA and glutamate control of calcium levels in GnRH neurons as well as effects of G-protein-coupled receptors for GnRH and kisspeptin. The simultaneous measurement of calcium levels in multiple GnRH neurons was hampered by variable rPericam fluorescence in different GnRH neurons. Nevertheless, in the multiple recordings that were achieved no evidence was found for synchronous calcium transients. Together, these observations show the great utility of transgenic targeting strategies for investigating the roles of calcium with specified neuronal cell types.
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Affiliation(s)
- Stéphanie Constantin
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin 9054, New Zealand
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Yuste R, MacLean J, Vogelstein J, Paninski L. Imaging action potentials with calcium indicators. Cold Spring Harb Protoc 2011; 2011:985-9. [PMID: 21807854 DOI: 10.1101/pdb.prot5650] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Medina KL, Nagel BJ, Tapert SF. Abnormal cerebellar morphometry in abstinent adolescent marijuana users. Psychiatry Res 2010; 182:152-9. [PMID: 20413277 PMCID: PMC2866789 DOI: 10.1016/j.pscychresns.2009.12.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 12/29/2009] [Accepted: 12/31/2009] [Indexed: 10/19/2022]
Abstract
Functional neuroimaging data from adults have, in general, revealed frontocerebellar dysfunction associated with acute and chronic marijuana (MJ) use. The goal of this study was to characterize cerebellar volume in adolescent chronic MJ users following 1 month of monitored abstinence. Participants were MJ users (n=16) and controls (n=16) aged 16-18 years. Extensive exclusionary criteria included history of psychiatric or neurologic disorders. Drug use history, neuropsychological data, and structural brain scans were collected after 28 days of monitored abstinence. Trained research staff defined cerebellar volumes (including three cerebellar vermis lobes and both cerebellar hemispheres) on high-resolution T1-weighted magnetic resonance images. Adolescent MJ users demonstrated significantly larger inferior posterior (lobules VIII-X) vermis volume than controls, above and beyond effects of lifetime alcohol and other drug use, gender, and intracranial volume. Larger vermis volumes were associated with poorer executive functioning. Following 1 month of abstinence, adolescent MJ users had significantly larger posterior cerebellar vermis volumes than non-using controls. These greater volumes are suggested to be pathological based on linkage to poorer executive functioning. Longitudinal studies are needed to examine typical cerebellar development during adolescence and the influence of marijuana use.
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Affiliation(s)
| | - Bonnie J. Nagel
- Department of Psychiatry, Oregon Health and Science University, Portland, Oregon
| | - Susan F. Tapert
- Department of Psychiatry, University of California, San Diego, California
,VA San Diego Healthcare System, San Diego, California
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Namiki S, Sasaki T, Matsuki N, Ikegaya Y. Regional difference in stainability with calcium-sensitive acetoxymethyl-ester probes in mouse brain slices. Int J Neurosci 2009; 119:214-26. [PMID: 19125375 DOI: 10.1080/00207450802330819] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Loading neurons with membrane permeable Ca2+ indicators is a core experimental procedure in functional multineuron Ca2+ imaging (fMCI), an optical technique for monitoring multiple neuronal activities. Although fMCI has been applied to several brain networks, including cerebral cortex, hippocampus, and cerebellum, no studies have systematically addressed the dye-loading efficiency in different brain regions. Here, we describe the stainability of Oregon Green 488 BAPTA-1AM in mouse acute brain slice preparations. The data are suggestive of the potential usability of fMCI in many brain regions, including olfactory bulb, thalamus, dentate gyrus, habenular nucleus, and pons.
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Affiliation(s)
- Shigehiro Namiki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
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Fusar-Poli P, Crippa JA, Bhattacharyya S, Borgwardt SJ, Allen P, Martin-Santos R, Seal M, Surguladze SA, O'Carrol C, Atakan Z, Zuardi AW, McGuire PK. Distinct effects of {delta}9-tetrahydrocannabinol and cannabidiol on neural activation during emotional processing. ACTA ACUST UNITED AC 2009; 66:95-105. [PMID: 19124693 DOI: 10.1001/archgenpsychiatry.2008.519] [Citation(s) in RCA: 323] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Cannabis use can both increase and reduce anxiety in humans. The neurophysiological substrates of these effects are unknown. OBJECTIVE To investigate the effects of 2 main psychoactive constituents of Cannabis sativa (Delta9-tetrahydrocannabinol [Delta9-THC] and cannabidiol [CBD]) on regional brain function during emotional processing. DESIGN Subjects were studied on 3 separate occasions using an event-related functional magnetic resonance imaging paradigm while viewing faces that implicitly elicited different levels of anxiety. Each scanning session was preceded by the ingestion of either 10 mg of Delta9-THC, 600 mg of CBD, or a placebo in a double-blind, randomized, placebo-controlled design. PARTICIPANTS Fifteen healthy, English-native, right-handed men who had used cannabis 15 times or less in their life. MAIN OUTCOME MEASURES Regional brain activation (blood oxygenation level-dependent response), electrodermal activity (skin conductance response [SCR]), and objective and subjective ratings of anxiety. RESULTS Delta9-Tetrahydrocannabinol increased anxiety, as well as levels of intoxication, sedation, and psychotic symptoms, whereas there was a trend for a reduction in anxiety following administration of CBD. The number of SCR fluctuations during the processing of intensely fearful faces increased following administration of Delta9-THC but decreased following administration of CBD. Cannabidiol attenuated the blood oxygenation level-dependent signal in the amygdala and the anterior and posterior cingulate cortex while subjects were processing intensely fearful faces, and its suppression of the amygdalar and anterior cingulate responses was correlated with the concurrent reduction in SCR fluctuations. Delta9-Tetrahydrocannabinol mainly modulated activation in frontal and parietal areas. CONCLUSIONS Delta9-Tetrahydrocannabinol and CBD had clearly distinct effects on the neural, electrodermal, and symptomatic response to fearful faces. The effects of CBD on activation in limbic and paralimbic regions may contribute to its ability to reduce autonomic arousal and subjective anxiety, whereas the anxiogenic effects of Delta9-THC may be related to effects in other brain regions.
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Affiliation(s)
- Paolo Fusar-Poli
- Neuroimaging Section, Division of Psychological Medicine, PO67, Institute of Psychiatry, London SE58AF, England.
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Medina KL, Hanson KL, Schweinsburg AD, Cohen-Zion M, Nagel BJ, Tapert SF. Neuropsychological functioning in adolescent marijuana users: subtle deficits detectable after a month of abstinence. J Int Neuropsychol Soc 2007; 13:807-20. [PMID: 17697412 PMCID: PMC2269704 DOI: 10.1017/s1355617707071032] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2006] [Revised: 03/13/2007] [Accepted: 03/14/2007] [Indexed: 11/06/2022]
Abstract
In adults, studies examining the long-lasting cognitive effects of marijuana use demonstrate subtle deficits in attention, executive function, and memory. Because neuromaturation continues through adolescence, these results cannot necessarily generalize to adolescent marijuana users. The goal of this study was to examine neuropsychological functioning in abstinent marijuana using and demographically similar control adolescents. Data were collected from 65 adolescent marijuana users (n=31, 26% females) and controls (n=34, 26% females) 16-18 years of age. Extensive exclusionary criteria included independent psychiatric, medical, and neurologic disorders. Neuropsychological assessments were conducted after>23 days of monitored abstinence. After controlling for lifetime alcohol use and depressive symptoms, adolescent marijuana users demonstrated slower psychomotor speed (p<.05), and poorer complex attention (p<.04), story memory (p<.04), and planning and sequencing ability (p<.001) compared with controls. Post hoc analysis revealed that the number of lifetime marijuana use episodes was associated with poorer cognitive function, even after controlling for lifetime alcohol use. The general pattern of results suggested that, even after a month of monitored abstinence, adolescent marijuana users demonstrate subtle neuropsychological deficits compared with nonusers. It is possible that frequent marijuana use during adolescence may negatively influence neuromaturation and cognitive development.
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Affiliation(s)
- Krista Lisdahl Medina
- Department of Psychiatry, University of California, San Diego, and Psychology Department, VA San Diego Healthcare System, San Diego, California 92161, USA
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Medina KL, Schweinsburg AD, Cohen-Zion M, Nagel BJ, Tapert SF. Effects of alcohol and combined marijuana and alcohol use during adolescence on hippocampal volume and asymmetry. Neurotoxicol Teratol 2006; 29:141-52. [PMID: 17169528 PMCID: PMC1821342 DOI: 10.1016/j.ntt.2006.10.010] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 10/30/2006] [Accepted: 10/30/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND Converging lines of evidence suggest that the hippocampus may be particularly vulnerable to deleterious effects of alcohol and marijuana use, especially during adolescence. The goal of this study was to examine hippocampal volume and asymmetry in adolescent users of alcohol and marijuana. METHODS Participants were adolescent (aged 15-18) alcohol (ALC) users (n=16), marijuana and alcohol (MJ+ALC) users (n=26), and demographically similar controls (n=21). Extensive exclusionary criteria included prenatal toxic exposure, left handedness, and psychiatric and neurologic disorders. Substance use, cognitive, and anatomical measures were collected after at least 2 days of abstinence from all substances. RESULTS Adolescent ALC users demonstrated a significantly different pattern of hippocampal asymmetry (p<.05) and reduced left hippocampal volume (p<.05) compared to MJ+ALC users and non-using controls. Increased alcohol abuse/dependence severity was associated with increased right>left (R>L) asymmetry and smaller left hippocampal volumes while marijuana abuse/dependence was associated with increased L>R asymmetry and larger left hippocampal volumes. Although MJ+ALC users did not differ from controls in asymmetry, functional relationships with verbal learning were found only among controls, among whom greater right than left hippocampal volume was associated with superior performance (p<.05). CONCLUSIONS Aberrations in hippocampal asymmetry and left hippocampal volumes were found for adolescent heavy drinkers. Further, the functional relationship between hippocampal asymmetry and verbal learning was abnormal among adolescent substance users compared to healthy controls. These findings suggest differential effects of alcohol and combined marijuana and alcohol use on hippocampal morphometry and the relationship between hippocampal asymmetry and verbal learning performance among adolescents.
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Affiliation(s)
- Krista Lisdahl Medina
- Department of Psychiatry, University of California, San Diego, CA
- Veterans Medical Research Foundation, San Diego, CA
| | - Alecia D. Schweinsburg
- Veterans Medical Research Foundation, San Diego, CA
- Department of Psychology, University of California, San Diego, CA
| | - Mairav Cohen-Zion
- Department of Psychiatry, University of California, San Diego, CA
- Veterans Medical Research Foundation, San Diego, CA
| | - Bonnie J. Nagel
- Department of Psychiatry, Oregon Health and Science University, Portland, OR
| | - Susan F. Tapert
- Veterans Affairs San Diego Healthcare System, San Diego, CA
- Department of Psychiatry, University of California, San Diego, CA
- Veterans Medical Research Foundation, San Diego, CA
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Tonini R, Ciardo S, Cerovic M, Rubino T, Parolaro D, Mazzanti M, Zippel R. ERK-dependent modulation of cerebellar synaptic plasticity after chronic Delta9-tetrahydrocannabinol exposure. J Neurosci 2006; 26:5810-8. [PMID: 16723539 PMCID: PMC6675260 DOI: 10.1523/jneurosci.5469-05.2006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chronic exposure to Delta9-tetrahydrocannabinol (THC) induces tolerance to cannabinoid-induced locomotor effects, which are mediated by cannabinoid receptors (CB1Rs) located in motor control regions, including the cerebellum. There is substantial evidence of cerebellar CB1R molecular adaptation and modifications in receptor signaling after prolonged cannabinoid exposure. However, very little is known about the effects of chronic cannabinoid administration on cerebellar synaptic plasticity, which may contribute to the development of cannabinoid behavioral tolerance. In the cerebellar cortex, activation of CB1R inhibits excitatory synaptic transmission at parallel fiber (PF)-Purkinje cell (PC) synapses by decreasing neurotransmitter release. Our study aimed to investigate the neurophysiological adaptive responses occurring at cerebellar PF-PC cell synapses after repeated THC exposure. In THC-tolerant mice, an increase of the basal release probability was found at PF-PC synapses, in parallel with a facilitation of slow mGluR1 (metabotropic glutamate receptor type 1)-mediated excitatory postsynaptic currents and a reduced sensitivity to the inhibitory effects of the CB1R agonist CP55,940 [(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol]. Additionally, after repeated THC exposures, presynaptic PF-PC long-term potentiation was blocked by A1R (adenosine receptor-1) activation. Inhibition of the extracellular signal regulated kinase (ERK) pathway prevented these alterations of cerebellar synaptic transmission and plasticity. In summary, we provide evidence for ERK-dependent modulatory mechanisms at PF-PC synapses after chronic THC administration. This contributes to generation of forms of pathological synaptic plasticity that might play a role in cannabinoid dependence.
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Affiliation(s)
- Raffaella Tonini
- Department of Cellular and Developmental Biology, University La Sapienza, 00185 Rome, Italy.
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Vallano ML, Beaman-Hall CM, Bui CJ, Middleton FA. Depolarization and Ca(2+) down regulate CB1 receptors and CB1-mediated signaling in cerebellar granule neurons. Neuropharmacology 2006; 50:651-60. [PMID: 16412482 DOI: 10.1016/j.neuropharm.2005.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 10/28/2005] [Accepted: 11/15/2005] [Indexed: 11/22/2022]
Abstract
Presynaptic terminals of cerebellar granule neurons are primary targets of cannabinoids, which act through type 1 G alpha(i/o)-coupled cannabinoid receptors (CB1) to modulate glutamate release. To study CB1 signaling investigators use primary cultures of granule neurons, typically grown in medium supplemented with elevated KCl to improve long-term survival. Herein, we demonstrate that CB1 expression and signaling are perturbed under these conditions. Specifically, immunochemical and RT-PCR assays indicate that depolarizing growth conditions decrease CB1 protein, mRNA and CB1-mediated inhibition of adenylyl cyclase compared to cultures grown in physiologic medium containing 5mM KCl. Depolarization-dependent downregulation of CB1 mRNA, like survival, is attenuated by L-type VDCC antagonists but not the Na(+)-channel antagonist, tetrodotoxin. Comparison of oligonucleotide microarrays from cultures grown in 5mM versus 25 mM KCl confirms that depolarization reduces CB1 mRNA, but not mRNAs encoding several G-protein subunits or adenylyl cyclases. However, significant alterations in synaptic signaling proteins that likely lie downstream of CB1 are observed, including K(+) channels, alpha-neurexins, cAMP-GEFII, Munc13-3, secretogranin and synaptotagmin. These findings make a compelling argument to adopt cultures grown in 5mM KCl for future study of CB1 signaling in granule neurons. Further, they suggest that a depolarization and Ca(2+)-dependent signaling pathway represses CB1 gene transcription.
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MESH Headings
- Age Factors
- Analysis of Variance
- Animals
- Animals, Newborn
- Blotting, Northern/methods
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Cell Survival/drug effects
- Cells, Cultured
- Cerebellum/cytology
- Cyclohexanols/pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Fluorescent Antibody Technique/methods
- Gene Expression Regulation, Developmental/drug effects
- Gene Expression Regulation, Developmental/physiology
- In Situ Hybridization/methods
- Models, Biological
- Neurons/physiology
- Neurons/radiation effects
- Nifedipine/pharmacology
- Potassium Chloride/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Tetrazolium Salts
- Tetrodotoxin/pharmacology
- Thiazoles
- Time Factors
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Affiliation(s)
- Mary Lou Vallano
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
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Castañé A, Maldonado R, Valverde O. Role of different brain structures in the behavioural expression of WIN 55,212-2 withdrawal in mice. Br J Pharmacol 2004; 142:1309-17. [PMID: 15265804 PMCID: PMC1575190 DOI: 10.1038/sj.bjp.0705882] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We have evaluated several responses induced by the cannabinoid agonist WIN 55,212-2 related to its addictive properties, including rewarding effects and the development of physical dependence in mice. Moreover, we have studied the specific involvement of several brain regions with high density of CB1 cannabinoid receptors, such as striatum, hippocampus, amygdala and cerebellum, in the behavioural expression of SR 141716A-precipitated WIN 55,212-2 withdrawal. The systemic administration of the CB1 receptor antagonist SR 141716A (10 mg kg(-1), s.c.) precipitated behavioural signs of withdrawal in mice chronically treated with WIN 55,212-2 (1 and 2 mg kg(-1), intraperitoneal (i.p.)), revealing the development of physical dependence. The microinjection of SR 141716A (1.5 and 3 micrograms) into the cerebellum induced severe manifestations of abstinence in mice dependent on WIN 55,212-2 (1 mg kg(-1), i.p.). Out of 10 signs evaluated, seven were statistically significant: wet dog shakes, body tremor, paw tremor, piloerection, mastication, genital licks and sniffing. When the cannabinoid antagonist was administered into the hippocampus and the amygdala, a moderate but significant withdrawal syndrome was also observed. However, no signs of abstinence were induced when SR 141716A was microinjected into the striatum. WIN 55,212-2 produced rewarding effects in the place-conditioning paradigm in mice pre-exposed to a priming injection of the drug. These results show a reliable behavioural model to reveal rewarding effects and physical dependence induced by the repeated administration of WIN 55,212-2 in mice. The cerebellum and to a lesser extent the hippocampus and the amygdala participate in the behavioural expression of cannabinoid withdrawal.
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Affiliation(s)
- Anna Castañé
- Laboratori de Neurofarmacologia, Facultat de Ciències de la Salut i de la Vida, Universitat Pompeu Fabra, C/ Dr. Aiguader, 80, 08003 Barcelona, Spain
| | - Rafael Maldonado
- Laboratori de Neurofarmacologia, Facultat de Ciències de la Salut i de la Vida, Universitat Pompeu Fabra, C/ Dr. Aiguader, 80, 08003 Barcelona, Spain
| | - Olga Valverde
- Laboratori de Neurofarmacologia, Facultat de Ciències de la Salut i de la Vida, Universitat Pompeu Fabra, C/ Dr. Aiguader, 80, 08003 Barcelona, Spain
- Author for correspondence:
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