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Brady RG, Rogers CE, Prochaska T, Kaplan S, Lean RE, Smyser TA, Shimony JS, Slavich GM, Warner BB, Barch DM, Luby JL, Smyser CD. The Effects of Prenatal Exposure to Neighborhood Crime on Neonatal Functional Connectivity. Biol Psychiatry 2022; 92:139-148. [PMID: 35428496 PMCID: PMC9257309 DOI: 10.1016/j.biopsych.2022.01.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/20/2021] [Accepted: 01/29/2022] [Indexed: 02/08/2023]
Abstract
BACKGROUND Maternal exposure to adversity during pregnancy has been found to affect infant brain development; however, the specific effect of prenatal crime exposure on neonatal brain connectivity remains unclear. Based on existing research, we hypothesized that living in a high-crime neighborhood during pregnancy would affect neonatal frontolimbic connectivity over and above other individual- and neighborhood-level adversity and that these associations would be mediated by maternal psychosocial stress. METHODS Participants included 399 pregnant women, recruited as part of the eLABE (Early Life Adversity, Biological Embedding, and Risk for Developmental Precursors of Mental Disorders) study. In the neonatal period, 319 healthy, nonsedated infants were scanned using resting-state functional magnetic resonance imaging (repetition time = 800 ms; echo time = 37 ms; voxel size = 2.0 × 2.0 × 2.0 mm3; multiband = 8) on a Prisma 3T scanner and had at least 10 minutes of high-quality data. Crime data at the block group level were obtained from Applied Geographic Solution. Linear regressions and mediation models tested associations between crime, frontolimbic connectivity, and psychosocial stress. RESULTS Living in a neighborhood with high property crime during pregnancy was related to weaker neonatal functional connectivity between the thalamus-anterior default mode network (aDMN) (β = -0.15, 95% CI = -0.25 to -0.04, p = .008). Similarly, high neighborhood violent crime was related to weaker functional connectivity between the thalamus-aDMN (β = -0.16, 95% CI = -0.29 to -0.04, p = .01) and amygdala-hippocampus (β = -0.16, 95% CI = -0.29 to -0.03, p = .02), controlling for other types of adversity. Psychosocial stress partially mediated relationships between the thalamus-aDMN and both violent and property crime. CONCLUSIONS These findings suggest that prenatal exposure to crime is associated with weaker neonatal limbic and frontal functional brain connections, providing another reason for targeted public policy interventions to reduce crime.
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Affiliation(s)
- Rebecca G Brady
- Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri; Department of Neurology, Washington University School of Medicine, St. Louis, Missouri.
| | - Cynthia E Rogers
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Trinidi Prochaska
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Sydney Kaplan
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - Rachel E Lean
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Tara A Smyser
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Joshua S Shimony
- Mallinckrot Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - George M Slavich
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California
| | - Barbara B Warner
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Deanna M Barch
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri; Mallinckrot Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri; Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, Missouri
| | - Joan L Luby
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Christopher D Smyser
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri; Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; Mallinckrot Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
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Craeghs L, Callaerts-Vegh Z, Verslegers M, Van der Jeugd A, Govaerts K, Dresselaers T, Wogensen E, Verreet T, Moons L, Benotmane MA, Himmelreich U, D'Hooge R. Prenatal Radiation Exposure Leads to Higher-Order Telencephalic Dysfunctions in Adult Mice That Coincide with Reduced Synaptic Plasticity and Cerebral Hypersynchrony. Cereb Cortex 2021; 32:3525-3541. [PMID: 34902856 DOI: 10.1093/cercor/bhab431] [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: 04/06/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/14/2022] Open
Abstract
Higher-order telencephalic circuitry has been suggested to be especially vulnerable to irradiation or other developmentally toxic impact. This report details the adult effects of prenatal irradiation at a sensitive time point on clinically relevant brain functions controlled by telencephalic regions, hippocampus (HPC), and prefrontal cortex (PFC). Pregnant C57Bl6/J mice were whole-body irradiated at embryonic day 11 (start of neurogenesis) with X-ray intensities of 0.0, 0.5, or 1.0 Gy. Female offspring completed a broad test battery of HPC-/PFC-controlled tasks that included cognitive performance, fear extinction, exploratory, and depression-like behaviors. We examined neural functions that are mechanistically related to these behavioral and cognitive changes, such as hippocampal field potentials and long-term potentiation, functional brain connectivity (by resting-state functional magnetic resonance imaging), and expression of HPC vesicular neurotransmitter transporters (by immunohistochemical quantification). Prenatally exposed mice displayed several higher-order dysfunctions, such as decreased nychthemeral activity, working memory defects, delayed extinction of threat-evoked response suppression as well as indications of perseverative behavior. Electrophysiological examination indicated impaired hippocampal synaptic plasticity. Prenatal irradiation also induced cerebral hypersynchrony and increased the number of glutamatergic HPC terminals. These changes in brain connectivity and plasticity could mechanistically underlie the irradiation-induced defects in higher telencephalic functions.
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Affiliation(s)
- Livine Craeghs
- Department of Brain & Cognition, Research Group Biological Psychology, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Zsuzsanna Callaerts-Vegh
- Department of Brain & Cognition, Research Group Biological Psychology, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Mieke Verslegers
- Department of Radiobiology, Institute for Environmental Health and Safety, Nuclear Research Center (SCK CEN), Mol 2400, Belgium
| | - Ann Van der Jeugd
- Department of Brain & Cognition, Research Group Biological Psychology, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Kristof Govaerts
- Department of Imaging & Pathology, Research Group Biomedical MRI, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Tom Dresselaers
- Department of Imaging & Pathology, Research Group Biomedical MRI, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Elise Wogensen
- Department of Brain & Cognition, Research Group Biological Psychology, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Tine Verreet
- Department of Radiobiology, Institute for Environmental Health and Safety, Nuclear Research Center (SCK CEN), Mol 2400, Belgium
| | - Lieve Moons
- Department of Biology, Research Group Neural Circuit Development and Regeneration, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Mohammed A Benotmane
- Department of Radiobiology, Institute for Environmental Health and Safety, Nuclear Research Center (SCK CEN), Mol 2400, Belgium
| | - Uwe Himmelreich
- Department of Imaging & Pathology, Research Group Biomedical MRI, University of Leuven (KU Leuven), Leuven 3000, Belgium
| | - Rudi D'Hooge
- Department of Brain & Cognition, Research Group Biological Psychology, University of Leuven (KU Leuven), Leuven 3000, Belgium
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Prenatal stress: Effects on fetal and child brain development. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 150:17-40. [DOI: 10.1016/bs.irn.2019.11.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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4
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Pan WJ, Billings J, Nezafati M, Abbas A, Keilholz S. Resting State fMRI in Rodents. ACTA ACUST UNITED AC 2019; 83:e45. [PMID: 30040200 DOI: 10.1002/cpns.45] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Resting state functional MRI (fMRI) and functional connectivity are widely applied in humans to examine the role of brain networks in normal function and dysfunction. A similar approach can be taken in rodents, either to obtain translational measures in models of brain disorders or to more carefully examine the neurophysiological underpinnings of the networks. A protocol for resting state functional connectivity in the anesthetized rat, from animal setup to data acquisition to possible pipelines for data analysis, is described. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Wen-Ju Pan
- Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, Georgia
| | - Jacob Billings
- Neuroscience Program, Emory University, Atlanta, Georgia
| | - Maysam Nezafati
- Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, Georgia
| | - Anzar Abbas
- Neuroscience Program, Emory University, Atlanta, Georgia
| | - Shella Keilholz
- Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, Georgia
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Mannheim JG, Kara F, Doorduin J, Fuchs K, Reischl G, Liang S, Verhoye M, Gremse F, Mezzanotte L, Huisman MC. Standardization of Small Animal Imaging-Current Status and Future Prospects. Mol Imaging Biol 2019; 20:716-731. [PMID: 28971332 DOI: 10.1007/s11307-017-1126-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The benefit of small animal imaging is directly linked to the validity and reliability of the collected data. If the data (regardless of the modality used) are not reproducible and/or reliable, then the outcome of the data is rather questionable. Therefore, standardization of the use of small animal imaging equipment, as well as of animal handling in general, is of paramount importance. In a recent paper, guidance for efficient small animal imaging quality control was offered and discussed, among others, the use of phantoms in setting up a quality control program (Osborne et al. 2016). The same phantoms can be used to standardize image quality parameters for multi-center studies or multi-scanners within center studies. In animal experiments, the additional complexity due to animal handling needs to be addressed to ensure standardized imaging procedures. In this review, we will address the current status of standardization in preclinical imaging, as well as potential benefits from increased levels of standardization.
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Affiliation(s)
- Julia G Mannheim
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany.
| | - Firat Kara
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Kerstin Fuchs
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Gerald Reischl
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Sayuan Liang
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | | | - Felix Gremse
- Institute for Experimental Molecular Imaging, RWTH Aachen University Clinic, Aachen, Germany
| | - Laura Mezzanotte
- Optical Molecular Imaging, Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marc C Huisman
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
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6
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Functional networks and network perturbations in rodents. Neuroimage 2017; 163:419-436. [DOI: 10.1016/j.neuroimage.2017.09.038] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/15/2017] [Accepted: 09/19/2017] [Indexed: 11/16/2022] Open
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Alterations in the expression of a neurodevelopmental gene exert long-lasting effects on cognitive-emotional phenotypes and functional brain networks: translational evidence from the stress-resilient Ahi1 knockout mouse. Mol Psychiatry 2017; 22:884-899. [PMID: 27021817 PMCID: PMC5444025 DOI: 10.1038/mp.2016.29] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/29/2015] [Accepted: 02/03/2016] [Indexed: 12/19/2022]
Abstract
Many psychiatric disorders are highly heritable and may represent the clinical outcome of early aberrations in the formation of neural networks. The placement of brain connectivity as an 'intermediate phenotype' renders it an attractive target for exploring its interaction with genomics and behavior. Given the complexity of genetic make up and phenotypic heterogeneity in humans, translational studies are indicated. Recently, we demonstrated that a mouse model with heterozygous knockout of the key neurodevelopmental gene Ahi1 displays a consistent stress-resilient phenotype. Extending these data, the current research describes our multi-faceted effort to link early variations in Ahi1 expression with long-term consequences for functional brain networks and cognitive-emotional phenotypes. By combining behavioral paradigms with graph-based analysis of whole-brain functional networks, and then cross-validating the data with robust neuroinformatic data sets, our research suggests that physiological variation in gene expression during neurodevelopment is eventually translated into a continuum of global network metrics that serve as intermediate phenotypes. Within this framework, we suggest that organization of functional brain networks may result, in part, from an adaptive trade-off between efficiency and resilience, ultimately culminating in a phenotypic diversity that encompasses dimensions such as emotional regulation and cognitive function.
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8
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Scheinost D, Sinha R, Cross SN, Kwon SH, Sze G, Constable RT, Ment LR. Does prenatal stress alter the developing connectome? Pediatr Res 2017; 81:214-226. [PMID: 27673421 PMCID: PMC5313513 DOI: 10.1038/pr.2016.197] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/30/2016] [Indexed: 12/22/2022]
Abstract
Human neurodevelopment requires the organization of neural elements into complex structural and functional networks called the connectome. Emerging data suggest that prenatal exposure to maternal stress plays a role in the wiring, or miswiring, of the developing connectome. Stress-related symptoms are common in women during pregnancy and are risk factors for neurobehavioral disorders ranging from autism spectrum disorder, attention deficit hyperactivity disorder, and addiction, to major depression and schizophrenia. This review focuses on structural and functional connectivity imaging to assess the impact of changes in women's stress-based physiology on the dynamic development of the human connectome in the fetal brain.
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Affiliation(s)
- Dustin Scheinost
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut
| | - Rajita Sinha
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut,Department of Child Study, Yale School of Medicine, New Haven, Connecticut,Department of Neuroscience, Yale School of Medicine, New Haven, Connecticut
| | - Sarah N. Cross
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut
| | - Soo Hyun Kwon
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut
| | - Gordon Sze
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut
| | - R. Todd Constable
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut,Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut
| | - Laura R. Ment
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut,Department of Neurology, Yale School of Medicine, New Haven, Connecticut,()
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9
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Finberg JPM, Rabey JM. Inhibitors of MAO-A and MAO-B in Psychiatry and Neurology. Front Pharmacol 2016; 7:340. [PMID: 27803666 PMCID: PMC5067815 DOI: 10.3389/fphar.2016.00340] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/12/2016] [Indexed: 01/24/2023] Open
Abstract
Inhibitors of MAO-A and MAO-B are in clinical use for the treatment of psychiatric and neurological disorders respectively. Elucidation of the molecular structure of the active sites of the enzymes has enabled a precise determination of the way in which substrates and inhibitor molecules are metabolized, or inhibit metabolism of substrates, respectively. Despite the knowledge of the strong antidepressant efficacy of irreversible MAO inhibitors, their clinical use has been limited by their side effect of potentiation of the cardiovascular effects of dietary amines (“cheese effect”). A number of reversible MAO-A inhibitors which are devoid of cheese effect have been described in the literature, but only one, moclobemide, is currently in clinical use. The irreversible inhibitors of MAO-B, selegiline and rasagiline, are used clinically in treatment of Parkinson's disease, and a recently introduced reversible MAO-B inhibitor, safinamide, has also been found efficacious. Modification of the pharmacokinetic characteristics of selegiline by transdermal administration has led to the development of a new drug form for treatment of depression. The clinical potential of MAO inhibitors together with detailed knowledge of the enzyme's binding site structure should lead to future developments with these drugs.
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Affiliation(s)
- John P M Finberg
- Rappaport Faculty of Medicine, Technion, Israel Institute of Technology Haifa, Israel
| | - Jose M Rabey
- Assaf Harofe Medical Center, Affiliated to Sackler School of Medicine, Tel Aviv University Tel Aviv, Israel
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10
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Prenatal stressors in rodents: Effects on behavior. Neurobiol Stress 2016; 6:3-13. [PMID: 28229104 PMCID: PMC5314420 DOI: 10.1016/j.ynstr.2016.08.004] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/07/2016] [Accepted: 08/08/2016] [Indexed: 12/13/2022] Open
Abstract
The current review focuses on studies in rodents published since 2008 and explores possible reasons for any differences they report in the effects of gestational stress on various types of behavior in the offspring. An abundance of experimental data shows that different maternal stressors in rodents can replicate some of the abnormalities in offspring behavior observed in humans. These include, anxiety, in juvenile and adult rats and mice, assessed in the elevated plus maze and open field tests and depression, detected in the forced swim and sucrose-preference tests. Deficits were reported in social interaction that is suggestive of pathology associated with schizophrenia, and in spatial learning and memory in adult rats in the Morris water maze test, but in most studies only males were tested. There were too few studies on the novel object recognition test at different inter-trial intervals to enable a conclusion about the effect of prenatal stress and whether any deficits are more prevalent in males. Among hippocampal glutamate receptors, NR2B was the only subtype consistently reduced in association with learning deficits. However, like in humans with schizophrenia and depression, prenatal stress lowered hippocampal levels of BDNF, which were closely correlated with decreases in hippocampal long-term potentiation. In mice, down-regulation of BDNF appeared to occur through the action of gene-methylating enzymes that are already increased above controls in prenatally-stressed neonates. In conclusion, the data obtained so far from experiments in rodents lend support to a physiological basis for the neurodevelopmental hypothesis of schizophrenia and depression.
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Zohar I, Shoham S, Weinstock M. Perinatal citalopram does not prevent the effect of prenatal stress on anxiety, depressive-like behaviour and serotonergic transmission in adult rat offspring. Eur J Neurosci 2016; 43:590-600. [PMID: 26669896 DOI: 10.1111/ejn.13150] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/26/2015] [Accepted: 12/07/2015] [Indexed: 12/17/2022]
Abstract
It is still not clear whether the selective serotonin reuptake inhibitors frequently prescribed to depressed pregnant women improve the behavioural outcome in their children. The current study investigated whether administration of citalopram to pregnant rats could prevent anxiety and depressive-like behaviour induced by gestational stress in their offspring, and restore the expression of serotonin 1A autoreceptors in GABAergic interneurons in the medial prefrontal cortex and dorsal raphe nuclei in males, and of corticotropin-releasing factor type 2 receptors in GABAergic interneurons in the dorsal raphe nuclei in females. Activation of these receptors modulates serotonergic transmission to target areas and is reduced in a sex-dependent manner by prenatal stress. Citalopram (10 mg/kg/day), administered orally from day 7 of gestation until 21 days postpartum, prevented the increase in anxiety in stressed mothers but did not reduce anxiety and depressive-like behaviour in their offspring and even induced depressive-like behaviour in the offspring of control mothers. Citalopram failed to restore the reduction in the expression of serotonin 1A autoreceptors in the prefrontal cortex of males and in corticotropin-releasing factor type 2 receptors in the dorsal raphe nuclei of females induced by prenatal stress. Prenatal citalopram did not prevent the behavioural changes or reduction in serotonergic transmission to target areas induced by prenatal stress. It had adverse behavioural effects in the offspring of control rats, which, together with the lack of any change in prenatally-stressed rats, may be due to inhibition of the foetal serotonin transporter thereby preventing normal development of the serotonin system.
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Affiliation(s)
- Inbar Zohar
- Department of Pharmacology, Institute of Drug Research, Hebrew University Medical Centre, Ein Kerem, Jerusalem, Israel
| | - Shai Shoham
- Department of Pharmacology, Institute of Drug Research, Hebrew University Medical Centre, Ein Kerem, Jerusalem, Israel
| | - Marta Weinstock
- Department of Pharmacology, Institute of Drug Research, Hebrew University Medical Centre, Ein Kerem, Jerusalem, Israel
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12
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Gordon N, Goelman G. Understanding alterations in serotonin connectivity in a rat model of depression within the monoamine-deficiency and the hippocampal-neurogenesis frameworks. Behav Brain Res 2015; 296:141-148. [PMID: 26367472 DOI: 10.1016/j.bbr.2015.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/06/2015] [Accepted: 09/09/2015] [Indexed: 11/19/2022]
Abstract
The monoamine-deficiency and the hippocampal-neurogenesis hypotheses of depression propose that alterations in the serotonin system and of hippocampal functionality are critical in the pathogenesis of depression. We measured the alterations in the connectivity level of the raphe nucleus in the chronic mild stress (CMS) rat model of depression using the manganese enhanced MRI method (MEMRI). Manganese ions were injected into the median raphe and their anterograde intracellular propagation was followed. Depression-like behavior was demonstrated using the sucrose preference tests. We show that the raphe's connectivity is differentially altered through chronic stress. In line with the monoamine-deficiency hypothesis, the connectivity of the raphe with the basal ganglia (BG) output nuclei, the hippocampus, the habenula and the entorhinal and insular cortices was reduced in CMS rats, suggesting an overall reduction in raphe excitability. Connectivity reductions were predominantly found in the right hemisphere, strengthening previous evidence pointing at a-symmetric hemispheric involvement in depression. Despite the general reduction in raphe connectivity, enhanced connectivity was found between the raphe and the septum, suggesting that alterations are connection-specific. On the basis of our results - while yet equivocal - we further discuss the possible coupling between the serotonergic and dopaminergic systems and two distinct mechanisms (direct and indirect) in which alterations in raphe connectivity may affect hippocampal dysfunction in chronic stress, thus linking the monoamine-deficiency and the hippocampal-neurogenesis hypotheses.
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Affiliation(s)
- Noam Gordon
- MRI Lab, The human Biology Research Center, Department of Medical Biophysics, Hadassah Hebrew University Medical Center, Jerusalem 91120 Israel; Cognition and Philosophy Lab, Monash University, Clayton, Victoria 3800, Australia
| | - Gadi Goelman
- MRI Lab, The human Biology Research Center, Department of Medical Biophysics, Hadassah Hebrew University Medical Center, Jerusalem 91120 Israel.
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13
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Pan WJ, Billings JCW, Grooms JK, Shakil S, Keilholz SD. Considerations for resting state functional MRI and functional connectivity studies in rodents. Front Neurosci 2015; 9:269. [PMID: 26300718 PMCID: PMC4525377 DOI: 10.3389/fnins.2015.00269] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/16/2015] [Indexed: 12/31/2022] Open
Abstract
Resting state functional MRI (rs-fMRI) and functional connectivity mapping have become widely used tools in the human neuroimaging community and their use is rapidly spreading into the realm of rodent research as well. One of the many attractive features of rs-fMRI is that it is readily translatable from humans to animals and back again. Changes in functional connectivity observed in human studies can be followed by more invasive animal experiments to determine the neurophysiological basis for the alterations, while exploratory work in animal models can identify possible biomarkers for further investigation in human studies. These types of interwoven human and animal experiments have a potentially large impact on neuroscience and clinical practice. However, impediments exist to the optimal application of rs-fMRI in small animals, some similar to those encountered in humans and some quite different. In this review we identify the most prominent of these barriers, discuss differences between rs-fMRI in rodents and in humans, highlight best practices for animal studies, and review selected applications of rs-fMRI in rodents. Our goal is to facilitate the integration of human and animal work to the benefit of both fields.
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Affiliation(s)
- Wen-Ju Pan
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA
| | | | - Joshua K Grooms
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA
| | - Sadia Shakil
- School of Electrical and Computer Engineering, Georgia Institute of Technology Atlanta, GA, USA
| | - Shella D Keilholz
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA ; Neuroscience Program, Emory University Atlanta, GA, USA
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Boersma GJ, Tamashiro KL. Individual differences in the effects of prenatal stress exposure in rodents. Neurobiol Stress 2015; 1:100-8. [PMID: 27589662 PMCID: PMC4721332 DOI: 10.1016/j.ynstr.2014.10.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/20/2014] [Accepted: 10/24/2014] [Indexed: 01/18/2023] Open
Abstract
Exposure to prenatal stress alters the phenotype of the offspring in adulthood. When the prenatal and adult environments do not match, these alterations may induce pathology risk. There are, however, large individual differences in the effects of prenatal stress. While some individuals seem vulnerable, others appear to be relatively resistant to its effects. In this review we discuss potential mechanisms underlying these individual differences with a focus on animal models. Differences between rodent models selected for stress coping traits are discussed. In addition, the role of circulating factors, like glucocorticoids and cytokines, factors involved in brain development and influences of epigenetic and genetic factors in prenatal stress induced phenotype are covered.
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Affiliation(s)
- Gretha J. Boersma
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Maximizing negative correlations in resting-state functional connectivity MRI by time-lag. PLoS One 2014; 9:e111554. [PMID: 25396416 PMCID: PMC4232255 DOI: 10.1371/journal.pone.0111554] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/12/2014] [Indexed: 01/07/2023] Open
Abstract
This paper aims to better understand the physiological meaning of negative correlations in resting state functional connectivity MRI (r-fcMRI). The correlations between anatomy-based brain regions of 18 healthy humans were calculated and analyzed with and without a correction for global signal and with and without spatial smoothing. In addition, correlations between anatomy-based brain regions of 18 naïve anesthetized rats were calculated and compared to the human data. T-statistics were used to differentiate between positive and negative connections. The application of spatial smoothing and global signal correction increased the number of significant positive connections but their effect on negative connections was complex. Positive connections were mainly observed between cortical structures while most negative connections were observed between cortical and non-cortical structures with almost no negative connections between non-cortical structures. In both human and rats, negative connections were never observed between bilateral homologous regions. The main difference between positive and negative connections in both the human and rat data was that positive connections became less significant with time-lags, while negative connections became more significant with time-lag. This effect was evident in all four types of analyses (with and without global signal correction and spatial smoothing) but was most significant in the analysis with no correction for the global signal. We hypothesize that the valence of r-fcMRI connectivity reflects the relative contributions of cerebral blood volume (CBV) and flow (CBF) to the BOLD signal and that these relative contributions are location-specific. If cerebral circulation is primarily regulated by CBF in one region and by CBV in another, a functional connection between these regions can manifest as an r-fcMRI negative and time-delayed correlation. Similarly, negative correlations could result from spatially inhomogeneous responses of rCBV or rCBF alone. Consequently, neuronal regulation of brain circulation may be deduced from the valence of r-fcMRI connectivity.
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