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Influence of three different anesthesia protocols on aged rat brain: a resting-state functional magnetic resonance imaging study. Chin Med J (Engl) 2020; 134:344-352. [PMID: 33074843 PMCID: PMC7846452 DOI: 10.1097/cm9.0000000000001126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising method for the study of brain function. Typically, rs-fMRI is performed on anesthetized animals. Although different functional connectivity (FC) in various anesthetics on whole brain have been studied, few studies have focused on different FC in the aged brain. Here, we measured FC under three commonly used anesthesia methods and analyzed data to determine if the FC in whole brain analysis were similar among groups. Methods Twenty-four male aged Wistar rats were randomly divided into three groups (n = 8 in each group). Anesthesia was performed under either isoflurane (ISO), combined ISO + dexmedetomidine (DEX) or α-chloralose (AC) according to the groups. Data of rs-fMRI was analyzed by FC in a voxel-wise way. Differences in the FC maps between the groups were analyzed by one-way analysis of variance and post hoc two-sample t tests. Results Compared with ISO + DEX anesthesia, ISO anesthesia caused increased FC in posterior brain and decreased FC in the middle brain of the aged rat. AC anesthesia caused global suppression as no increase in FC was observed. Conclusion ISO could be used as a substitute for ISO + DEX in rat default mode network studies if the left temporal association cortex is not considered important.
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Solleveld MM, Schrantee A, Homberg JR, Lucassen PJ, Reneman L. The influence of age-of-onset of antidepressant use on the acute CBF response to a citalopram challenge; a pharmacological MRI study. Psychiatry Res Neuroimaging 2020; 303:111126. [PMID: 32592855 DOI: 10.1016/j.pscychresns.2020.111126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 06/03/2020] [Accepted: 06/11/2020] [Indexed: 11/21/2022]
Abstract
Preclinical studies have demonstrated that antidepressant treatment in juvenile rodents affect the ontogeny of the serotonin system. However, whether early antidepressant use has similar effects on the development of the serotonin system in humans remains unknown. Therefore, we investigated whether effects of selective serotonin reuptake inhibitor (SSRI) treatment on the serotonin system are modulated by age. With pharmacological Magnetic Resonance Imaging the cerebral blood flow (CBF) response to an acute citalopram challenge was measured, as a proxy for serotonin function. Fifty-one females with major depressive disorder or anxiety disorder were stratified into three groups: 1) those treated with SSRIs <23 years of age, 2) those treated with SSRIs >23 years of age, and 3) those that were never treated with SSRIs. Additionally, a group of 14 healthy controls was included. CBF decreased after a citalopram challenge in the amygdala, hippocampus and orbitofrontal cortex across the whole sample. However, in contrast to preclinical studies, we did not find any age-dependent effect of SSRI exposure on the CBF response. In view of recent concerns on potential adverse effects of SSRIs administered to children, future studies are needed to replicate our negative findings in larger samples sizes and potentially in a prospective design.
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Affiliation(s)
- Michelle M Solleveld
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands; Swammerdam Institute for Life Sciences, Center for Neurosciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Anouk Schrantee
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Judith R Homberg
- Department of Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Paul J Lucassen
- Swammerdam Institute for Life Sciences, Center for Neurosciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Liesbeth Reneman
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
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Vidal B, Bolbos R, Redouté J, Langlois JB, Costes N, Newman-Tancredi A, Zimmer L. Pharmacological MRI to investigate the functional selectivity of 5-HT 1A receptor biased agonists. Neuropharmacology 2019; 172:107867. [PMID: 31783063 DOI: 10.1016/j.neuropharm.2019.107867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 01/03/2023]
Abstract
The emerging concept of "biased agonism" denotes the phenomenon whereby agonists can preferentially direct receptor signalling to specific intracellular responses among the different transduction pathways, thus potentially avoiding side effects and improving therapeutic effects. The aim of this study was to investigate biased agonism by using pharmacological magnetic resonance imaging (phMRI). The cerebral blood oxygen level dependent (BOLD) signal changes induced by increasing doses of two serotonin 5-HT1A receptor biased agonists, NLX-112 and NLX-101, were mapped in anaesthetized rats. Although both compounds display high affinity, selectivity and agonist efficacy for 5-HT1A receptors, NLX-101 is known to preferentially activate post-synaptic receptors, whereas NLX-112 targets both pre- and post-synaptic receptors. We used several doses of agonists in order to determine if the regional selectivity of NLX-101 was dose-dependent. NLX-112 and NLX-101 induced different positive and negative hemodynamic changes patterns at equal doses. Importantly, NLX-101 had no significant effect in regions expressing pre-synaptic receptors contrary to NLX-112. NLX-112 also produced higher BOLD changes than NLX-101 in the orbital cortex, the somatosensory cortex, and the magnocellular preoptic nuclei. In other regions such as the retrosplenial cortex and the dorsal thalamus, the drugs had similar effects. In terms of functional connectivity, NLX-112 induced more widespread changes than NLX-101. The present phMRI study demonstrates that two closely-related agonists display notable differences in their hemodynamic "fingerprints". These data support the concept of biased agonism at 5-HT1A receptors and raise the prospect of identifying novel therapeutics which exhibit improved targeting of brain regions implicated in neuropsychiatric disorders. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.
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Affiliation(s)
- Benjamin Vidal
- Université de Lyon, Lyon Neuroscience Research Center, INSERM, CNRS, Bron, France
| | | | | | | | | | | | - Luc Zimmer
- Université de Lyon, Lyon Neuroscience Research Center, INSERM, CNRS, Bron, France; CERMEP-Imagerie du Vivant, Bron, France; Hospices Civils de Lyon, Lyon, France; National Institute for Nuclear Science and Technology, Saclay, France.
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Kim M, Kwak S, Yoon YB, Kwak YB, Kim T, Cho KIK, Lee TY, Kwon JS. Functional connectivity of the raphe nucleus as a predictor of the response to selective serotonin reuptake inhibitors in obsessive-compulsive disorder. Neuropsychopharmacology 2019; 44:2073-2081. [PMID: 31189178 PMCID: PMC6898154 DOI: 10.1038/s41386-019-0436-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/06/2019] [Accepted: 06/03/2019] [Indexed: 11/10/2022]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are first-line pharmacological agents for treating obsessive-compulsive disorder (OCD). However, because nearly half of patients show insufficient SSRI responses, serotonergic dysfunction in heterogeneous OCD patients should be investigated for precision medicine. We aimed to determine whether functional connectivity (FC) of the raphe nucleus (RN), the major source of most serotonergic neurons, was altered in OCD patients and could predict the SSRI response. A total of 102 medication-free OCD patients and 101 matched healthy control (HC) subjects participated in resting-state functional magnetic resonance imaging. Among them, 54 OCD patients were treated with SSRIs for 16 weeks, resulting in 26 responders and 28 nonresponders. Seed-based whole brain FC with the RN as a seed region was compared between the OCD and HC groups, as well as between SSRI responders and nonresponders. FC cluster values showing significant group differences were used to investigate factors correlated with symptomatic severity before treatment and predictive of SSRI response. Compared to HCs, OCD patients exhibited significantly larger FC between the RN and temporal cortices including the middle temporal gyrus (MTG), paracingulate gyrus, amygdala, hippocampus, putamen, thalamus, and brain stem. Greater RN-left MTG FC was positively correlated with OC symptom severity at baseline. In addition, larger FC of the RN-left MTG was also found in SSRI nonresponders compared to responders, which was a significant predictor of SSRI response after 16 weeks. The FC of RN may reflect the neurobiological underpinning of OCD and could aid future precision medicine as a differential brain-based biomarker.
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Affiliation(s)
- Minah Kim
- 0000 0001 0302 820Xgrid.412484.fDepartment of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea ,0000 0004 0470 5905grid.31501.36Department of Psychiatry, Seoul National University College of Medicine, 101 Daehak-no, Chongno-gu, Seoul, 03080 Republic of Korea
| | - Seoyeon Kwak
- 0000 0004 0470 5905grid.31501.36Department of Brain and Cognitive Sciences, Seoul National University College of Natural Science, Seoul, Republic of Korea
| | - Youngwoo Bryan Yoon
- 0000 0001 2355 7002grid.4367.6Department of Psychiatry, Washington University in St. Louis, St. Louis, MO USA
| | - Yoo Bin Kwak
- 0000 0004 0470 5905grid.31501.36Department of Brain and Cognitive Sciences, Seoul National University College of Natural Science, Seoul, Republic of Korea
| | - Taekwan Kim
- 0000 0004 0470 5905grid.31501.36Department of Brain and Cognitive Sciences, Seoul National University College of Natural Science, Seoul, Republic of Korea
| | - Kang Ik K. Cho
- 0000 0004 0470 5905grid.31501.36Department of Brain and Cognitive Sciences, Seoul National University College of Natural Science, Seoul, Republic of Korea
| | - Tae Young Lee
- 0000 0001 0302 820Xgrid.412484.fDepartment of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jun Soo Kwon
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea. .,Department of Psychiatry, Seoul National University College of Medicine, 101 Daehak-no, Chongno-gu, Seoul, 03080, Republic of Korea. .,Department of Brain and Cognitive Sciences, Seoul National University College of Natural Science, Seoul, Republic of Korea. .,Institute of Human Behavioral Medicine, SNU-MRC, Seoul, Republic of Korea.
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Schrantee A, Solleveld MM, Schwantje H, Bruin WB, Mutsaerts HJMM, Adriaanse SM, Lucassen P, Booij J, Reneman L. Dose-dependent effects of the selective serotonin reuptake inhibitor citalopram: A combined SPECT and phMRI study. J Psychopharmacol 2019; 33:660-669. [PMID: 30887865 PMCID: PMC6572584 DOI: 10.1177/0269881119836229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Serotonin transporter blockers, like citalopram, dose-dependently bind to the serotonin transporter. Pharmacological magnetic resonance imaging (phMRI) can be used to non-invasively monitor effects of serotonergic medication. Although previous studies showed that phMRI can measure the effect of a single dose of serotoninergic medication, it is currently unclear whether it can also detect dose-dependent effects. AIMS To investigate the dose-dependent phMRI response to citalopram and compared this with serotonin transporter occupancy, measured with single photon emission computed tomography (SPECT). METHODS Forty-five healthy females were randomized to pre-treatment with placebo, a low (4 mg) or clinically standard (16 mg) oral citalopram dose. Prior to citalopram, and 3 h after, subjects underwent SPECT scanning. Subsequently, a phMRI scan with a citalopram challenge (7.5 mg intravenously) was conducted. Change in cerebral blood flow in response to the citalopram challenge was assessed in the thalamus and occipital cortex (control region). RESULTS Citalopram dose-dependently affected serotonin transporter occupancy, as measured with SPECT. In addition, citalopram dose-dependently affected the phMRI response to intravenous citalopram in the thalamus (but not occipital cortex), but phMRI was less sensitive in distinguishing between groups than SPECT. Serotonin transporter occupancy showed a trend-significant correlation to thalamic cerebral blood flow change. CONCLUSION These results suggest that phMRI likely suffers from higher variation than SPECT, but that these techniques probably also assess different functional aspects of the serotonergic synapse; therefore phMRI could complement positron emission tomography/SPECT for measuring effects of serotonergic medication.
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Affiliation(s)
- Anouk Schrantee
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands,Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands,A Schrantee, Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
| | - Michelle M Solleveld
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands,Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Hilde Schwantje
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
| | - Willem B Bruin
- Amsterdam University Medical Centers, Academic Medical Center, Department of Psychiatry, Amsterdam, The Netherlands
| | - Henk-Jan MM Mutsaerts
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
| | - Sofie M Adriaanse
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
| | - Paul Lucassen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Jan Booij
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
| | - Liesbeth Reneman
- Amsterdam University Medical Centers, Academic Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
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In vivo biased agonism at 5-HT 1A receptors: characterisation by simultaneous PET/MR imaging. Neuropsychopharmacology 2018; 43:2310-2319. [PMID: 30030540 PMCID: PMC6135772 DOI: 10.1038/s41386-018-0145-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/07/2018] [Accepted: 06/27/2018] [Indexed: 12/26/2022]
Abstract
In neuropharmacology, the recent concept of 'biased agonism' denotes the capacity of certain agonists to target-specific intracellular pathways of a given receptor in specific brain areas. In the context of serotonin pharmacotherapy, 5-HT1A receptor-biased agonists could be of great interest in several neuropsychiatric disorders. The aim of this study was to determine whether biased agonists could be differentiated in terms of regional targeting by use of simultaneous functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) brain imaging. We compared two 5-HT1A-biased agonists, NLX-112 and NLX-101, injected at three different doses in anaesthetised cats (n = 4). PET imaging was acquired for 90 min after bolus administration followed by constant infusion of the 5-HT1A radiotracer, [18F]MPPF. Drug occupancy was evaluated after injection at 50 min and BOLD fMRI was simultaneously acquired to evaluate subsequent brain activation patterns. 5-HT1A receptor occupancy was found to be dose-dependent for both agonists, but differed in magnitude and spatial distribution at equal doses with distinct BOLD patterns. Functional connectivity, as measured by BOLD signal temporal correlations between regions, was also differently modified by NLX-112 or NLX-101. Voxel-based correlation analyses between PET and fMRI suggested that NLX-112 stimulates both 5-HT1A autoreceptors and post-synaptic receptors, whereas NLX-101 preferentially stimulates post-synaptic cortical receptors. In cingulate cortex, the agonists induced opposite BOLD signal changes in response to receptor occupancy. These data constitute the first simultaneous exploration of 5-HT1A occupancy and its consequences in terms of brain activation, and demonstrates differential signalling by two 5-HT1A-biased agonists. Combined PET/fMRI represents a powerful tool in neuropharmacology, and opens new ways to address the concept of biased agonism by translational approaches.
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Huang P, Dong Z, Huang W, Zhou C, Zhong W, Hu P, Wen G, Sun X, Hua H, Cao H, Gao L, Lv Z. Voluntary wheel running ameliorates depression-like behaviors and brain blood oxygen level-dependent signals in chronic unpredictable mild stress mice. Behav Brain Res 2017; 330:17-24. [DOI: 10.1016/j.bbr.2017.05.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 11/29/2022]
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Blood oxygen level-dependent signals via fMRI in the mood-regulating circuit using two animal models of depression are reversed by chronic escitalopram treatment. Behav Brain Res 2016; 311:210-218. [DOI: 10.1016/j.bbr.2016.05.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/15/2016] [Accepted: 05/21/2016] [Indexed: 01/22/2023]
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Klomp A, Hamelink R, Feenstra M, Denys D, Reneman L. Increased response to a 5-HT challenge after discontinuation of chronic serotonin uptake inhibition in the adult and adolescent rat brain. PLoS One 2014; 9:e99873. [PMID: 24937739 PMCID: PMC4061036 DOI: 10.1371/journal.pone.0099873] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/20/2014] [Indexed: 12/13/2022] Open
Abstract
Little is known about the effects of chronic fluoxetine on 5-HT transmission in the adolescent brain, even though it is acknowledged that the neuroplasticity of the brain during childhood and adolescence might influence the neurobiological mechanisms underlying treatment response. Also, possible ongoing effects on monoamine function following drug discontinuation are unidentified. We therefore examined the chronic effects of fluoxetine on extracellular 5-HT and dopamine concentrations in the medial prefrontal cortex and studied their responsiveness to an acute 5-HT challenge after a one-week washout period, both in adolescent and adult rats. Noradrenaline was measured in adult animals only. Fluoxetine increased 5-HT to 200-300% of control and DA and NA to 150% of control. Although there were no lasting effects of chronic fluoxetine on basal monoamine levels, we observed a clear potentiating effect of previous treatment on the fluoxetine-induced increase in extracellular 5-HT and, to a lesser extent, extracellular DA. No differential effect was found for noradrenaline. Age-at-treatment did not influence these results. So, after cessation of chronic fluoxetine treatment 5-HT responsiveness remains heightened. This may be indicative of the continuing presence of 5-HT receptor desensitization, at least until one week after drug discontinuation in rats. No apparent age-at-treatment effects on extracellular monoamine concentrations in the medial prefrontal cortex were detected, but age-related differences in 5-HT transmission further down-stream or in the recovery processes cannot be ruled out.
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Affiliation(s)
- Anne Klomp
- Department of Radiology, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Ralph Hamelink
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Matthijs Feenstra
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Damiaan Denys
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Liesbeth Reneman
- Department of Radiology, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
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Scharinger C, Rabl U, Kasess CH, Meyer BM, Hofmaier T, Diers K, Bartova L, Pail G, Huf W, Uzelac Z, Hartinger B, Kalcher K, Perkmann T, Haslacher H, Meyer-Lindenberg A, Kasper S, Freissmuth M, Windischberger C, Willeit M, Lanzenberger R, Esterbauer H, Brocke B, Moser E, Sitte HH, Pezawas L. Platelet serotonin transporter function predicts default-mode network activity. PLoS One 2014; 9:e92543. [PMID: 24667541 PMCID: PMC3965432 DOI: 10.1371/journal.pone.0092543] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/25/2014] [Indexed: 12/16/2022] Open
Abstract
Background The serotonin transporter (5-HTT) is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT) from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence. Methods A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (Vmax) was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA) to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD) activity and platelet Vmax. Results The present study demonstrates that increases in platelet Vmax significantly predict default-mode network (DMN) suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet Vmax is related to global DMN activation and not intrinsic DMN connectivity. Conclusion This study provides evidence that platelet Vmax predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal Vmax coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.
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Affiliation(s)
- Christian Scharinger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Ulrich Rabl
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Christian H. Kasess
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Bernhard M. Meyer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Tina Hofmaier
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
- Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Kersten Diers
- Department of Psychology, Dresden University of Technology, Dresden, Germany
| | - Lucie Bartova
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Gerald Pail
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Huf
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Statistics and Probability Theory, Vienna University of Technology, Vienna, Austria
| | - Zeljko Uzelac
- Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Beate Hartinger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Klaudius Kalcher
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Statistics and Probability Theory, Vienna University of Technology, Vienna, Austria
| | - Thomas Perkmann
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Helmuth Haslacher
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Michael Freissmuth
- Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Christian Windischberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Matthäus Willeit
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Burkhard Brocke
- Department of Psychology, Dresden University of Technology, Dresden, Germany
| | - Ewald Moser
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Harald H. Sitte
- Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Lukas Pezawas
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Couch Y, Martin CJ, Howarth C, Raley J, Khrapitchev AA, Stratford M, Sharp T, Sibson NR, Anthony DC. Systemic inflammation alters central 5-HT function as determined by pharmacological MRI. Neuroimage 2013; 75:177-186. [PMID: 23473937 PMCID: PMC4004801 DOI: 10.1016/j.neuroimage.2013.02.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 02/18/2013] [Accepted: 02/20/2013] [Indexed: 02/02/2023] Open
Abstract
Considerable evidence indicates a link between systemic inflammation and central 5-HT function. This study used pharmacological magnetic resonance imaging (phMRI) to study the effects of systemic inflammatory events on central 5-HT function. Changes in blood oxygenation level dependent (BOLD) contrast were detected in selected brain regions of anaesthetised rats in response to intravenous administration of the 5-HT-releasing agent, fenfluramine (10 mg/kg). Further groups of rats were pre-treated with the bacterial lipopolysaccharide (LPS; 0.5 mg/kg), to induce systemic inflammation, or the selective 5-HT2A receptor antagonist MDL100907 prior to fenfluramine. The resultant phMRI data were investigated further through measurements of cortical 5-HT release (microdialysis), and vascular responsivity, as well as a more thorough investigation of the role of the 5-HT2A receptor in sickness behaviour. Fenfluramine evoked a positive BOLD response in the motor cortex (+15.9±2%) and a negative BOLD response in the dorsal raphe nucleus (-9.9±4.2%) and nucleus accumbens (-7.7±5.3%). In all regions, BOLD responses to fenfluramine were significantly attenuated by pre-treatment with LPS (p<0.0001), but neurovascular coupling remained intact, and fenfluramine-evoked 5-HT release was not affected. However, increased expression of the 5-HT2A receptor mRNA and decreased 5-HT2A-dependent behaviour (wet-dog shakes) was a feature of the LPS treatment and may underpin the altered phMRI signal. MDL100907 (0.5 mg/kg), 5-HT2A antagonist, significantly reduced the BOLD responses to fenfluramine in all three regions (p<0.0001) in a similar manner to LPS. Together these results suggest that systemic inflammation decreases brain 5-HT activity as assessed by phMRI. However, these effects do not appear to be mediated by changes in 5-HT release, but are associated with changes in 5-HT2A-receptor-mediated downstream signalling pathways.
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Affiliation(s)
- Yvonne Couch
- Department of Pharmacology, University of Oxford, Mansfield Rd, Oxford, OX1 3QT, UK; CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Chris J Martin
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Clare Howarth
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Josie Raley
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Alexandre A Khrapitchev
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Michael Stratford
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Mansfield Rd, Oxford, OX1 3QT, UK
| | - Nicola R Sibson
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford, OX3 7LJ, UK.
| | - Daniel C Anthony
- Department of Pharmacology, University of Oxford, Mansfield Rd, Oxford, OX1 3QT, UK
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Schouw MLJ, Gevers S, Caan MWA, Majoie CBLM, Booij J, Nederveen AJ, Reneman L. Mapping serotonergic dysfunction in MDMA (ecstasy) users using pharmacological MRI. Eur Neuropsychopharmacol 2012; 22:537-45. [PMID: 22209360 DOI: 10.1016/j.euroneuro.2011.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 10/12/2011] [Accepted: 12/02/2011] [Indexed: 11/30/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA or ecstasy) is a popular recreational drug that has been shown to induce loss of brain serotonin (5-HT) neurons. The purpose of this study was to determine the usefulness of pharmacological magnetic resonance imaging (phMRI) in assessing 5-HT dysfunction by examining the hemodynamic response evoked by infusion with the selective 5-HT reuptake inhibitor citalopram. We studied the effects of MDMA on brain hemodynamics using arterial spin labeling (ASL) based phMRI following a citalopram challenge (7.5mg/kg, i.v.), combined with [¹²³I]β-CIT SPECT imaging in ten male MDMA users and seven healthy non-users. Single photon emission computed tomography (SPECT) imaging was used to assess the availability of 5-HT transporters (SERT). Imaging results were compared with the results of behavioral measures and mood changes following drug administration, in both groups (using the Beck Depression Inventory, Barratt Impulsiveness Scale and a visual analog scale). Reductions in SERT binding were observed in the occipital cortex of MDMA users. In line with this, citalopram induced decreases in cerebral blood flow (CBF) in the occipital cortex of MDMA users. ASL based phMRI also detected a CBF decrease in the thalamus of MDMA users. In concordance with imaging findings, behavioral measures differed significantly between MDMA users and controls. MDMA users had higher impulsivity scores and felt more uncomfortable after citalopram infusion, compared with control subjects. Our findings indicate that phMRI is very well suited for in-vivo assessment of 5-HT dysfunction.
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Affiliation(s)
- M L J Schouw
- Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Bouet V, Klomp A, Freret T, Wylezinska-Arridge M, Lopez-Tremoleda J, Dauphin F, Boulouard M, Booij J, Gsell W, Reneman L. Age-dependent effects of chronic fluoxetine treatment on the serotonergic system one week following treatment. Psychopharmacology (Berl) 2012; 221:329-39. [PMID: 22205158 DOI: 10.1007/s00213-011-2580-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Accepted: 11/07/2011] [Indexed: 01/08/2023]
Abstract
RATIONALE Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine are increasingly used for the treatment of depression in children. Limited data are, however, available on their effects on brain development and their efficacy remains debated. Moreover, previous experimental studies are seriously hampered in their clinical relevance. OBJECTIVES The aim of the present study was to investigate putative age-related effects of a chronic treatment with fluoxetine (5 mg/kg, either orally or i.p. for 3 weeks, 1 week washout) using conventional methods (behavioral testing and binding assay using [(123)I]β-CIT) and a novel magnetic resonance imaging (MRI) approach. METHODS Behavior was assessed, as well as serotonin transporter (SERT) availability and function through ex vivo binding assays and in vivo pharmacological MRI (phMRI) with an acute fluoxetine challenge (10 mg/kg oral or 5 mg/kg i.v.) in adolescent and adult rats. RESULTS Fluoxetine caused an increase in anxiety-like behavior in treated adult, but not adolescent, rats. On the binding assays, we observed increased SERT densities in most cortical brain regions and hypothalamus in adolescent, but not adult, treated rats. Finally, reductions in brain activation were observed with phMRI following treatment, in both adult and adolescent treated animals. CONCLUSION Collectively, our data indicate that the short-term effects of fluoxetine on the 5-HT system may be age-dependent. These findings could reflect structural and functional rearrangements in the developing brain that do not occur in the matured rat brain. phMRI possibly will be well suited to study this important issue in the pediatric population.
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Affiliation(s)
- Valentine Bouet
- Groupe Mémoire et Plasticité comportementale (GMPc), Université de Caen Basse-Normandie, Caen, France.
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Klomp A, Tremoleda JL, Schrantee A, Gsell W, Reneman L. The use of pharmacological-challenge fMRI in pre-clinical research: application to the 5-HT system. J Vis Exp 2012:3956. [PMID: 22565099 PMCID: PMC3466645 DOI: 10.3791/3956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel underlying neurobiological mechanisms behind drug action and neurotransmitter-related disorders, such as depression and ADHD. Like most of the imaging methods (PET, SPECT, CT) it represents a progress in the investigation of brain disorders and the related function of neurotransmitter pathways in a non-invasive way with respect of the overall neuronal connectivity. Moreover it also provides the ideal tool for translation to clinical investigations. MRI, while still behind in molecular imaging strategies compared to PET and SPECT, has the great advantage to have a high spatial resolution and no need for the injection of a contrast-agent or radio-labeled molecules, thereby avoiding the repetitive exposure to ionizing radiations. Functional MRI (fMRI) is extensively used in research and clinical setting, where it is generally combined with a psycho-motor task. phMRI is an adaptation of fMRI enabling the investigation of a specific neurotransmitter system, such as serotonin (5-HT), under physiological or pathological conditions following activation via administration of a specific challenging drug. The aim of the method described here is to assess brain 5-HT function in free-breathing animals. By challenging the 5-HT system while simultaneously acquiring functional MR images over time, the response of the brain to this challenge can be visualized. Several studies in animals have already demonstrated that drug-induced increases in extracellular levels of e.g. 5-HT (releasing agents, selective re-uptake blockers, etc) evoke region-specific changes in blood oxygenation level dependent (BOLD) MRI signals (signal due to a change of the oxygenated/deoxygenated hemoglobin levels occurring during brain activation through an increase of the blood supply to supply the oxygen and glucose to the demanding neurons) providing an index of neurotransmitter function. It has also been shown that these effects can be reversed by treatments that decrease 5-HT availability16,13,18,7. In adult rats, BOLD signal changes following acute SSRI administration have been described in several 5-HT related brain regions, i.e. cortical areas, hippocampus, hypothalamus and thalamus9,16,15. Stimulation of the 5-HT system and its response to this challenge can be thus used as a measure of its function in both animals and humans2,11.
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Affiliation(s)
- Anne Klomp
- Department of Radiology, Brain Imaging Center, Academic Medical Center Amsterdam
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15
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Klomp A, Tremoleda JL, Wylezinska M, Nederveen AJ, Feenstra M, Gsell W, Reneman L. Lasting effects of chronic fluoxetine treatment on the late developing rat brain: age-dependent changes in the serotonergic neurotransmitter system assessed by pharmacological MRI. Neuroimage 2011; 59:218-26. [PMID: 21840402 DOI: 10.1016/j.neuroimage.2011.07.082] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 07/18/2011] [Accepted: 07/26/2011] [Indexed: 01/26/2023] Open
Abstract
RATIONALE With the growing prevalence of psychotropic drug prescriptions among children and adolescents, the need for studies on lasting effects of drug exposure on the developing brain rises. Fluoxetine is the only selective serotonin reuptake inhibitor (SSRI) officially registered to treat major depressive disorder in children. Although various (pre)clinical studies have assessed the (long-term) effects of fluoxetine exposure in the perinatal period and in adulthood, limited data is available on its effects on the developing brain later in life, i.e. during adolescence. OBJECTIVE The present study aimed at investigating the effects of age following chronic SSRI treatment on the central serotonin (5-HT) system. To this end, pharmacological MRI (phMRI) was performed in chronic fluoxetine-treated (5 mg/kg, oral gavage for 3 weeks) juvenile (PND25) and adult rats (PND65) after a 1-week washout period, using an acute fluoxetine challenge (5 mg/kg, i.v.) to trigger the 5-HT system. RESULTS We observed a diminished brain response to the acute challenge in adult treated animals when compared to control animals, whereas this response was increased in juvenile treated rats. As a result, a significant age by treatment interaction effect was seen in several (subcortical) 5-HT related brain regions. CONCLUSION An opposite effect of chronic fluoxetine treatment was seen in the developing brain compared to that in matured brain, as assessed non-invasively using phMRI. These findings most likely reflect neuronal imprinting effects of juvenile SSRI treatment and may underlie emotional disturbances seen in animals and children treated with this drug. Also, our findings suggest that phMRI might be ideally suited to study this important issue in the pediatric population.
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Affiliation(s)
- A Klomp
- Department of Radiology, Academic Medical Centre Amsterdam, Netherlands.
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Increased amygdala response to positive social feedback in young people with major depressive disorder. Biol Psychiatry 2011; 69:734-41. [PMID: 21257158 DOI: 10.1016/j.biopsych.2010.12.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 12/08/2010] [Accepted: 12/08/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND Studies of depressed patients have demonstrated increased amygdala activation to negative affective stimuli. In this study, we used a paradigm that employed personally relevant social stimuli, which are known to strongly activate the amygdala, to test whether the amygdala demonstrated aberrant activity in depressed participants as they responded to stimuli with positive valence. METHODS Nineteen patients with major depressive disorder, aged 15 to 24 years, were matched with 20 healthy control participants. They completed a novel functional magnetic resonance imaging task in which they received social feedback from people who they believed had evaluated them. Voxelwise statistical parametric maps of brain response to positive social feedback and to a control feedback condition were compared to test the hypothesis that differences in neural response between depressed and control participants would arise in the amygdala. RESULTS Depressed participants showed increased neural response to the positive- versus control-feedback condition in the amygdala (p < .05, corrected). An exploratory analysis showed that depressed participants responded to faces from both feedback conditions with increased activity in regions subserving social appraisal (ventrolateral prefrontal cortex and inferior parietal cortex) and affective processing (pregenual anterior cingulate cortex and anterior insular cortex; p < .001, uncorrected). CONCLUSIONS Depressed patients responded to positive social feedback with increased amygdala activation, demonstrating that amygdala hyperresponsivity in depression is not restricted to negatively-valenced stimuli. The heightened sensitivity of depressed participants to social evaluation may help explain symptoms of depression such as social withdrawal.
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Scharinger C, Rabl U, Sitte HH, Pezawas L. Imaging genetics of mood disorders. Neuroimage 2010; 53:810-21. [PMID: 20156570 PMCID: PMC4502568 DOI: 10.1016/j.neuroimage.2010.02.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 01/17/2010] [Accepted: 02/09/2010] [Indexed: 12/15/2022] Open
Abstract
Mood disorders are highly heritable and have been linked to brain regions of emotion processing. Over the past few years, an enormous amount of imaging genetics studies has demonstrated the impact of risk genes on brain regions and systems of emotion processing in vivo in healthy subjects as well as in mood disorder patients. While sufficient evidence already exists for several monaminergic genes as well as for a few non-monoaminergic genes, such as brain-derived neurotrophic factor (BDNF) in healthy subjects, many others only have been investigated in single studies so far. Apart from these studies, the present review also covers imaging genetics studies applying more complex genetic disease models of mood disorders, such as epistasis and gene-environment interactions, and their impact on brain systems of emotion processing. This review attempts to provide a comprehensive overview of the rapidly growing field of imaging genetics studies in mood disorder research.
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Affiliation(s)
- Christian Scharinger
- Division of Biological Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Ulrich Rabl
- Division of Biological Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Harald H. Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Austria
| | - Lukas Pezawas
- Division of Biological Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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Nie B, Hui J, Wang L, Chai P, Gao J, Liu S, Zhang Z, Shan B, Zhao S. Automatic method for tracing regions of interest in rat brain magnetic resonance imaging studies. J Magn Reson Imaging 2010; 32:830-5. [DOI: 10.1002/jmri.22283] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Dodd GT, Williams SR, Luckman SM. Functional magnetic resonance imaging and c-Fos mapping in rats following a glucoprivic dose of 2-deoxy-D-glucose. J Neurochem 2010; 113:1123-32. [PMID: 20236391 DOI: 10.1111/j.1471-4159.2010.06671.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The glucose analogue, 2-deoxy-D-glucose (2-DG) is an inhibitor of glycolysis and, when administered systemically or centrally, induces glucoprivation leading to counter-regulatory responses, including increased feeding behaviour. Investigations into how the brain responds to glucoprivation could have important therapeutic potential, as disruptions or defects in the defence of the brain's 'glucostatic' circuitry may be partly responsible for pathological conditions resulting from diabetes and obesity. To define the 'glucostat' brain circuitry further we have combined blood-oxygen-level-dependent pharmacological-challenge magnetic resonance imaging (phMRI) with whole-brain c-Fos functional activity mapping to characterise brain regions responsive to an orexigenic dose of 2-DG [200 mg/kg; subcutaneous (s.c.)]. For phMRI, rats were imaged using a T(2)*-weighted gradient echo in a 7T magnet for 60 min under alpha-chloralose anaesthesia, whereas animals for immunohistochemistry were unanaesthetised and freely behaving. These complementary methods demonstrated functional brain activity in a number of previously characterised glucose-sensing brain regions such as those in the hypothalamus and brainstem following administration of 2-DG compared with vehicle. As the study mapped whole-brain functional responses, it also identified the orbitofrontal cortex and striatum (nucleus accumbens and ventral pallidum) as novel 2-DG-responsive brain regions. These regions make up a corticostriatal connection with the hypothalamus, by which aspects of motivation, salience and reward can impinge on the hypothalamic control of feeding behaviour. This study, therefore, provides further evidence for a common integrated circuit involved in the induction of feeding behaviour, and illustrates the valuable potential of phMRI in investigating central pharmacological actions.
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Affiliation(s)
- Garron T Dodd
- Faculty of Life Sciences, AV Hill Building, University of Manchester, Oxford Road, Manchester, UK
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Dodd G, Stark J, Mckie S, Williams S, Luckman S. Central cannabinoid signaling mediating food intake: a pharmacological-challenge magnetic resonance imaging and functional histology study in rat. Neuroscience 2009; 163:1192-200. [DOI: 10.1016/j.neuroscience.2009.07.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 06/24/2009] [Accepted: 07/09/2009] [Indexed: 11/30/2022]
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