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Farsi Z, Nicolella A, Simmons SK, Aryal S, Shepard N, Brenner K, Lin S, Herzog L, Moran SP, Stalnaker KJ, Shin W, Gazestani V, Song BJ, Bonanno K, Keshishian H, Carr SA, Pan JQ, Macosko EZ, Datta SR, Dejanovic B, Kim E, Levin JZ, Sheng M. Brain-region-specific changes in neurons and glia and dysregulation of dopamine signaling in Grin2a mutant mice. Neuron 2023; 111:3378-3396.e9. [PMID: 37657442 DOI: 10.1016/j.neuron.2023.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 05/19/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
A genetically valid animal model could transform our understanding of schizophrenia (SCZ) disease mechanisms. Rare heterozygous loss-of-function (LoF) mutations in GRIN2A, encoding a subunit of the NMDA receptor, greatly increase the risk of SCZ. By transcriptomic, proteomic, and behavioral analyses, we report that heterozygous Grin2a mutant mice show (1) large-scale gene expression changes across multiple brain regions and in neuronal (excitatory and inhibitory) and non-neuronal cells (astrocytes and oligodendrocytes), (2) evidence of hypoactivity in the prefrontal cortex (PFC) and hyperactivity in the hippocampus and striatum, (3) an elevated dopamine signaling in the striatum and hypersensitivity to amphetamine-induced hyperlocomotion (AIH), (4) altered cholesterol biosynthesis in astrocytes, (5) a reduction in glutamatergic receptor signaling proteins in the synapse, and (6) an aberrant locomotor pattern opposite of that induced by antipsychotic drugs. These findings reveal potential pathophysiologic mechanisms, provide support for both the "hypo-glutamate" and "hyper-dopamine" hypotheses of SCZ, and underscore the utility of Grin2a-deficient mice as a genetic model of SCZ.
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Affiliation(s)
- Zohreh Farsi
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Ally Nicolella
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sean K Simmons
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sameer Aryal
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nate Shepard
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kira Brenner
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sherry Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Linnea Herzog
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sean P Moran
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Katherine J Stalnaker
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Wangyong Shin
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea
| | - Vahid Gazestani
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Bryan J Song
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kevin Bonanno
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hasmik Keshishian
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Steven A Carr
- Proteomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jen Q Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Evan Z Macosko
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Massachusetts General Hospital, Department of Psychiatry, Boston, MA, USA
| | | | - Borislav Dejanovic
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, South Korea; Department of Biological Sciences, Korea Advanced Institute for Science and Technology, Daejeon, South Korea
| | - Joshua Z Levin
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Morgan Sheng
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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2
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Lodge DJ, Elam HB, Boley AM, Donegan JJ. Discrete hippocampal projections are differentially regulated by parvalbumin and somatostatin interneurons. Nat Commun 2023; 14:6653. [PMID: 37863893 PMCID: PMC10589277 DOI: 10.1038/s41467-023-42484-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2023] [Indexed: 10/22/2023] Open
Abstract
People with schizophrenia show hyperactivity in the ventral hippocampus (vHipp) and we have previously demonstrated distinct behavioral roles for vHipp cell populations. Here, we test the hypothesis that parvalbumin (PV) and somatostatin (SST) interneurons differentially innervate and regulate hippocampal pyramidal neurons based on their projection target. First, we use eGRASP to show that PV-positive interneurons form a similar number of synaptic connections with pyramidal cells regardless of their projection target while SST-positive interneurons preferentially target nucleus accumbens (NAc) projections. To determine if these anatomical differences result in functional changes, we used in vivo opto-electrophysiology to show that SST cells also preferentially regulate the activity of NAc-projecting cells. These results suggest vHipp interneurons differentially regulate that vHipp neurons that project to the medial prefrontal cortex (mPFC) and NAc. Characterization of these cell populations may provide potential molecular targets for the treatment schizophrenia and other psychiatric disorders associated with vHipp dysfunction.
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Affiliation(s)
- Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX, USA
| | - Hannah B Elam
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX, USA
| | - Angela M Boley
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX, USA
| | - Jennifer J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
- Department of Psychiatry and Behavioral Sciences and Center for Early Life Adversity, Department of Neuroscience, Dell Medical School at the University of Texas at Austin, Austin, TX, 78712, USA.
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3
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Lee JJ, Piras E, Tamburini S, Bu K, Wallach DS, Remsen B, Cantor A, Kong J, Goetz D, Hoffman KW, Bonner M, Joe P, Mueller BR, Robinson-Papp J, Lotan E, Gonen O, Malaspina D, Clemente JC. Gut and oral microbiome modulate molecular and clinical markers of schizophrenia-related symptoms: A transdiagnostic, multilevel pilot study. Psychiatry Res 2023; 326:115279. [PMID: 37331068 PMCID: PMC10595250 DOI: 10.1016/j.psychres.2023.115279] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/09/2023] [Accepted: 05/30/2023] [Indexed: 06/20/2023]
Abstract
Although increasing evidence links microbial dysbiosis with the risk for psychiatric symptoms through the microbiome-gut-brain axis (MGBA), the specific mechanisms remain poorly characterized. In a diagnostically heterogeneous group of treated psychiatric cases and nonpsychiatric controls, we characterized the gut and oral microbiome, plasma cytokines, and hippocampal inflammatory processes via proton magnetic resonance spectroscopic imaging (1H-MRSI). Using a transdiagnostic approach, these data were examined in association with schizophrenia-related symptoms measured by the Positive and Negative Syndrome Scale (PANSS). Psychiatric cases had significantly greater heterogeneity of gut alpha diversity and an enrichment of pathogenic taxa, like Veillonella and Prevotella, in the oral microbiome, which was an accurate classifier of phenotype. Cases exhibited significantly greater positive, negative, and general PANSS scores that uniquely correlated with bacterial taxa. Strong, positive correlations of bacterial taxa were also found with cytokines and hippocampal gliosis, dysmyelination, and excitatory neurotransmission. This pilot study supports the hypothesis that the MGBA influences psychiatric symptomatology in a transdiagnostic manner. The relative importance of the oral microbiome in peripheral and hippocampal inflammatory pathways was highlighted, suggesting opportunities for probiotics and oral health to diagnose and treat psychiatric conditions.
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Affiliation(s)
- Jakleen J Lee
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Enrica Piras
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Sabrina Tamburini
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kevin Bu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - David S Wallach
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Brooke Remsen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Adam Cantor
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Jennifer Kong
- Academy for the Advancement of Science and Technology, Bergen County Academies, Hackensack, NJ, United States
| | - Deborah Goetz
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kevin W Hoffman
- Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Mharisi Bonner
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Peter Joe
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Bridget R Mueller
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Jessica Robinson-Papp
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Eyal Lotan
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Oded Gonen
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Dolores Malaspina
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
| | - Jose C Clemente
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States; Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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4
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McCoy AM, Prevot TD, Sharmin D, Cook JM, Sibille EL, Lodge DJ. GL-II-73, a Positive Allosteric Modulator of α5GABA A Receptors, Reverses Dopamine System Dysfunction Associated with Pilocarpine-Induced Temporal Lobe Epilepsy. Int J Mol Sci 2023; 24:11588. [PMID: 37511346 PMCID: PMC10380722 DOI: 10.3390/ijms241411588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/15/2023] [Accepted: 07/16/2023] [Indexed: 07/30/2023] Open
Abstract
Although seizures are a hallmark feature of temporal lobe epilepsy (TLE), psychiatric comorbidities, including psychosis, are frequently associated with TLE and contribute to decreased quality of life. Currently, there are no defined therapeutic protocols to manage psychosis in TLE patients, as antipsychotic agents may induce epileptic seizures and are associated with severe side effects and pharmacokinetic and pharmacodynamic interactions with antiepileptic drugs. Thus, novel treatment strategies are necessary. Several lines of evidence suggest that hippocampal hyperactivity is central to the pathology of both TLE and psychosis; therefore, restoring hippocampal activity back to normal levels may be a novel therapeutic approach for treating psychosis in TLE. In rodent models, increased activity in the ventral hippocampus (vHipp) results in aberrant dopamine system function, which is thought to underlie symptoms of psychosis. Indeed, we have previously demonstrated that targeting α5-containing γ-aminobutyric acid receptors (α5GABAARs), an inhibitory receptor abundant in the hippocampus, with positive allosteric modulators (PAMs), can restore dopamine system function in rodent models displaying hippocampal hyperactivity. Thus, we posited that α5-PAMs may be beneficial in a model used to study TLE. Here, we demonstrate that pilocarpine-induced TLE is associated with increased VTA dopamine neuron activity, an effect that was completely reversed by intra-vHipp administration of GL-II-73, a selective α5-PAM. Further, pilocarpine did not alter the hippocampal α5GABAAR expression or synaptic localization that may affect the efficacy of α5-PAMs. Taken together, these results suggest augmenting α5GABAAR function as a novel therapeutic modality for the treatment of psychosis in TLE.
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Affiliation(s)
- Alexandra M McCoy
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Dishary Sharmin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Etienne L Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, TX 78229, USA
- South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, TX 78229, USA
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5
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McHugo M, Avery S, Armstrong K, Rogers BP, Vandekar SN, Woodward ND, Blackford JU, Heckers S. Anterior hippocampal dysfunction in early psychosis: a 2-year follow-up study. Psychol Med 2023; 53:160-169. [PMID: 33875028 PMCID: PMC8919704 DOI: 10.1017/s0033291721001318] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Cross-sectional studies indicate that hippocampal function is abnormal across stages of psychosis. Neural theories of psychosis pathophysiology suggest that dysfunction worsens with illness stage. Here, we test the hypothesis that hippocampal function is impaired in the early stage of psychosis and declines further over the next 2 years. METHODS We measured hippocampal function over 2 years using a scene processing task in 147 participants (76 individuals in the early stage of a non-affective psychotic disorder and 71 demographically similar healthy control individuals). Two-year follow-up was completed in 97 individuals (50 early psychosis, 47 healthy control). Voxelwise longitudinal analysis of activation in response to scenes was carried out within a hippocampal region of interest to test for group differences at baseline and a group by time interaction. RESULTS At baseline, we observed lower anterior hippocampal activation in the early psychosis group relative to the healthy control group. Contrary to our hypothesis, hippocampal activation remained consistent and did not show the predicted decline over 2 years in the early psychosis group. Healthy controls showed a modest reduction in hippocampal activation after 2 years. CONCLUSIONS The results of this study suggest that hippocampal dysfunction in early psychosis does not worsen over 2 years and highlight the need for longer-term longitudinal studies.
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Affiliation(s)
- Maureen McHugo
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Suzanne Avery
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kristan Armstrong
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Baxter P. Rogers
- Vanderbilt University Institute of Imaging Sciences, Nashville, TN, USA
| | - Simon N. Vandekar
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Neil D. Woodward
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jennifer Urbano Blackford
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Research and Development, Tennessee Valley Healthcare System, United States Department of Veteran Affairs
| | - Stephan Heckers
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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6
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Malaspina D. A sister's search for the seeds of psychosis. Psychiatry Res 2022; 317:114846. [PMID: 36244157 DOI: 10.1016/j.psychres.2022.114846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/07/2022] [Accepted: 09/11/2022] [Indexed: 01/04/2023]
Abstract
Dr. Dolores Malaspina sought a better way to understand the origins of psychosis than a schizophrenogenic mother, as her family had been informed upon her sisters illness. She moved her attention from environmental biology and zoology, to medical science and assembled knowledge on the multilevel components purported to underpin severe mental illness. Her studies cross levels to consider connections among exposures and genetic etiologies, intrinsic homeostatic mechanisms, stimuli perception and clinical illness features. Original contributions include associating later paternal age with increasing risk for schizophrenia in offspring and proposing that de novo mutations with shorter cell cycles explained the association, showing increased resting hippocampal blood flow in psychosis and that it was associated with inflammation, and that autonomic nervous system dysfunction was related to hippocampal inflammation, plausibly reflecting vascular abnormalities. She has been a professor of psychiatry in medical schools at Columbia University, New York University and at Mount Sinai in New York, USA.
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Affiliation(s)
- Dolores Malaspina
- Department of Psychiatry, Neuroscience, Genetic & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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7
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Joe P, Clemente JC, Piras E, Wallach DS, Robinson-Papp J, Boka E, Remsen B, Bonner M, Kimhy D, Goetz D, Hoffman K, Lee J, Ruby E, Fendrich S, Gonen O, Malaspina D. An integrative study of the microbiome gut-brain-axis and hippocampal inflammation in psychosis: Persistent effects from mode of birth. Schizophr Res 2022; 247:101-115. [PMID: 34625336 PMCID: PMC8980116 DOI: 10.1016/j.schres.2021.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 12/20/2022]
Abstract
The mechanism producing psychosis appears to include hippocampal inflammation, which could be associated with the microbiome-gut-brain-axis (MGBS). To test this hypothesis we are conducting a multidisciplinary study, herein described. The procedures are illustrated with testing of a single subject and group level information on the impact of C-section birth are presented. METHOD Study subjects undergo research diagnostic interviews and symptom assessments to be categorized into one of 3 study groups: psychosis, nonpsychotic affective disorder or healthy control. Hippocampal volume and metabolite concentrations are assessed using 3-dimensional, multi-voxel H1 Magnetic Resonance Imaging (MRSI) encompassing all gray matter in the entire hippocampal volume. Rich self-report information is obtained with the PROMIS interview, which was developed by the NIH Commons for research in chronic conditions. Early trauma is assessed and cognition is quantitated using the MATRICS. The method also includes the most comprehensive autonomic nervous system (ANS) battery used to date in psychiatric research. Stool and oral samples are obtained for microbiome assessments and cytokines and other substances are measured in blood samples. RESULTS Group level preliminary data shows that C-section birth is associated with higher concentrations of GLX, a glutamate related hippocampal neurotransmitter in psychotic cases, worse symptoms in affective disorder cases and smaller hippocampal volume in controls. CONCLUSION Mode of birth appears to have persistent influences through adulthood. The methodology described for this study will define pathways through which the MGBA may influence the risk for psychiatric disorders.
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Affiliation(s)
- Peter Joe
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA.
| | - Jose C Clemente
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, New York, NY, USA
| | - Enrica Piras
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, New York, NY, USA
| | - David S Wallach
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, New York, NY, USA
| | | | - Emeka Boka
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA
| | - Brooke Remsen
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA; Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, New York, NY, USA
| | - Mharisi Bonner
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA
| | - David Kimhy
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA
| | - Deborah Goetz
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA
| | - Kevin Hoffman
- Perelman School of Medicine, University of Pennsylvania, Department of Psychiatry, Philadelphia, PA, USA
| | - Jakleen Lee
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, New York, NY, USA
| | - Eugene Ruby
- University of California, Los Angeles, Department of Psychology, Los Angeles, CA, USA
| | - Sarah Fendrich
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA; Perelman School of Medicine, University of Pennsylvania, Center for Health Care Incentives & Behavioral Economics, Philadelphia, PA, USA
| | - Oded Gonen
- NYU Langone Medical Center, Department of Radiology, New York, NY, USA
| | - Dolores Malaspina
- Icahn School of Medicine at Mount Sinai, Department of Psychiatry, New York, NY, USA
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8
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Ouellette J, Lacoste B. From Neurodevelopmental to Neurodegenerative Disorders: The Vascular Continuum. Front Aging Neurosci 2021; 13:749026. [PMID: 34744690 PMCID: PMC8570842 DOI: 10.3389/fnagi.2021.749026] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Structural and functional integrity of the cerebral vasculature ensures proper brain development and function, as well as healthy aging. The inability of the brain to store energy makes it exceptionally dependent on an adequate supply of oxygen and nutrients from the blood stream for matching colossal demands of neural and glial cells. Key vascular features including a dense vasculature, a tightly controlled environment, and the regulation of cerebral blood flow (CBF) all take part in brain health throughout life. As such, healthy brain development and aging are both ensured by the anatomical and functional interaction between the vascular and nervous systems that are established during brain development and maintained throughout the lifespan. During critical periods of brain development, vascular networks remodel until they can actively respond to increases in neural activity through neurovascular coupling, which makes the brain particularly vulnerable to neurovascular alterations. The brain vasculature has been strongly associated with the onset and/or progression of conditions associated with aging, and more recently with neurodevelopmental disorders. Our understanding of cerebrovascular contributions to neurological disorders is rapidly evolving, and increasing evidence shows that deficits in angiogenesis, CBF and the blood-brain barrier (BBB) are causally linked to cognitive impairment. Moreover, it is of utmost curiosity that although neurodevelopmental and neurodegenerative disorders express different clinical features at different stages of life, they share similar vascular abnormalities. In this review, we present an overview of vascular dysfunctions associated with neurodevelopmental (autism spectrum disorders, schizophrenia, Down Syndrome) and neurodegenerative (multiple sclerosis, Huntington's, Parkinson's, and Alzheimer's diseases) disorders, with a focus on impairments in angiogenesis, CBF and the BBB. Finally, we discuss the impact of early vascular impairments on the expression of neurodegenerative diseases.
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Affiliation(s)
- Julie Ouellette
- Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
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9
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Kätzel D, Wolff AR, Bygrave AM, Bannerman DM. Hippocampal Hyperactivity as a Druggable Circuit-Level Origin of Aberrant Salience in Schizophrenia. Front Pharmacol 2020; 11:486811. [PMID: 33178010 PMCID: PMC7596262 DOI: 10.3389/fphar.2020.486811] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/18/2020] [Indexed: 01/21/2023] Open
Abstract
The development of current neuroleptics was largely aiming to decrease excessive dopaminergic signaling in the striatum. However, the notion that abnormal dopamine creates psychotic symptoms by causing an aberrant assignment of salience that drives maladaptive learning chronically during disease development suggests a therapeutic value of early interventions that correct salience-related neural processing. The mesolimbic dopaminergic output is modulated by several interconnected brain-wide circuits centrally involving the hippocampus and key relays like the ventral and associative striatum, ventral pallidum, amygdala, bed nucleus of the stria terminalis, nucleus reuniens, lateral and medial septum, prefrontal and cingulate cortex, among others. Unraveling the causal relationships between these circuits using modern neuroscience techniques holds promise for identifying novel cellular—and ultimately molecular—treatment targets for reducing transition to psychosis and symptoms of schizophrenia. Imaging studies in humans have implicated a hyperactivity of the hippocampus as a robust and early endophenotype in schizophrenia. Experiments in rodents, in turn, suggested that the activity of its output region—the ventral subiculum—may modulate dopamine release from ventral tegmental area (VTA) neurons in the ventral striatum. Even though these observations suggested a novel circuit-level target for anti-psychotic action, no therapy has yet been developed along this rationale. Recently evaluated treatment strategies—at least in part—target excess glutamatergic activity, e.g. N-acetyl-cysteine (NAC), levetiracetam, and mGluR2/3 modulators. We here review the evidence for the central implication of the hippocampus-VTA axis in schizophrenia-related pathology, discuss its symptom-related implications with a particular focus on aberrant assignment of salience, and evaluate some of its short-comings and prospects for drug discovery.
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Affiliation(s)
- Dennis Kätzel
- Institute for Applied Physiology, Ulm University, Ulm, Germany
| | - Amy R Wolff
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Alexei M Bygrave
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
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10
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Donegan JJ, Lodge DJ. Stem Cells for Improving the Treatment of Neurodevelopmental Disorders. Stem Cells Dev 2020; 29:1118-1130. [PMID: 32008442 PMCID: PMC7469694 DOI: 10.1089/scd.2019.0265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Treatment options for neurodevelopmental disorders such as schizophrenia and autism are currently limited. Antipsychotics used to treat schizophrenia are not effective for all patients, do not target all symptoms of the disease, and have serious adverse side effects. There are currently no FDA-approved drugs to treat the core symptoms of autism. In an effort to develop new and more effective treatment strategies, stem cell technologies have been used to reprogram adult somatic cells into induced pluripotent stem cells, which can be differentiated into neuronal cells and even three-dimensional brain organoids. This new technology has the potential to elucidate the complex mechanisms that underlie neurodevelopmental disorders, offer more relevant platforms for drug discovery and personalized medicine, and may even be used to treat the disease.
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Affiliation(s)
- Jennifer J. Donegan
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Daniel J. Lodge
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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11
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Donegan JJ, Boley AM, Glenn JP, Carless MA, Lodge DJ. Developmental alterations in the transcriptome of three distinct rodent models of schizophrenia. PLoS One 2020; 15:e0232200. [PMID: 32497066 PMCID: PMC7272013 DOI: 10.1371/journal.pone.0232200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/09/2020] [Indexed: 11/25/2022] Open
Abstract
Schizophrenia is a debilitating disorder affecting just under 1% of the population. While the symptoms of this disorder do not appear until late adolescence, pathological alterations likely occur earlier, during development in utero. While there is an increasing literature examining transcriptome alterations in patients, it is not possible to examine the changes in gene expression that occur during development in humans that will develop schizophrenia. Here we utilize three distinct rodent developmental disruption models of schizophrenia to examine potential overlapping alterations in the transcriptome, with a specific focus on markers of interneuron development. Specifically, we administered either methylazoxymethanol acetate (MAM), Polyinosinic:polycytidylic acid (Poly I:C), or chronic protein malnutrition, on GD 17 and examined mRNA expression in the developing hippocampus of the offspring 18 hours later. Here, we report alterations in gene expression that may contribute to the pathophysiology of schizophrenia, including significant alterations in interneuron development and ribosome function.
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Affiliation(s)
- Jennifer J. Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, United States of America
| | - Angela M. Boley
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, United States of America
| | - Jeremy P. Glenn
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX, United States of America
| | - Melanie A. Carless
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX, United States of America
| | - Daniel J. Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, United States of America
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12
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Gomes FV, Zhu X, Grace AA. Stress during critical periods of development and risk for schizophrenia. Schizophr Res 2019; 213:107-113. [PMID: 30711313 PMCID: PMC6667322 DOI: 10.1016/j.schres.2019.01.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 12/20/2022]
Abstract
Schizophrenia is a neurodevelopmental disorder with genetic predisposition, and stress has long been linked to its etiology. While stress affects all stages of the illness, increasing evidence suggests that stress during critical periods of development may be particularly detrimental, increasing individual's vulnerability to psychosis. To thoroughly understand the potential causative role of stress, our group has been focusing on the prenatal methylazoxymethanol acetate (MAM) rodent model, and discovered that MAM offspring display abnormal stress reactivity and heightened anxiety prepubertally, prior to the manifestation of a hyperdopaminergic state. Furthermore, pharmacologically treating anxiety during prepuberty prevented the emergence of the dopamine dysfunction in adulthood. Interestingly, sufficiently strong stressors applied to normal rats selectively during early development can recapitulate multiple schizophrenia-related phenotypes of MAM rats, whereas the same stress paradigm during adulthood only produced short-term depression-related deficits. Altogether, the evidence is thus converging: developmental disruption (genetic or environmental) might render animals more susceptible to the deleterious effects of stress during critical time windows, during which unregulated stress can lead to the emergence of psychosis later in life. As an important region regulating the midbrain dopamine system, the ventral hippocampus is particularly vulnerable to stress, and the distinct maturational profile of its fast-spiking parvalbumin interneurons may largely underlie such vulnerability. In this review, by discussing emerging evidence spanning clinical and basic science studies, we propose developmental stress vulnerability as a novel link between early predispositions and environmental triggering events in the pathophysiology of schizophrenia. This promising line of research can potentially provide not only insights into the etiology, but also a "roadmap" for disease prevention.
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Affiliation(s)
| | | | - Anthony A. Grace
- Corresponding author: Dr. Anthony A. Grace - Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, PA, 15260, USA. Phone: +1 412 624 4609.
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13
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Zöller D, Sandini C, Karahanoğlu FI, Padula MC, Schaer M, Eliez S, Van De Ville D. Large-Scale Brain Network Dynamics Provide a Measure of Psychosis and Anxiety in 22q11.2 Deletion Syndrome. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:881-892. [DOI: 10.1016/j.bpsc.2019.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/06/2019] [Indexed: 12/21/2022]
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14
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Perez SM, Donegan JJ, Lodge DJ. Effect of estrous cycle on schizophrenia-like behaviors in MAM exposed rats. Behav Brain Res 2019; 362:258-265. [PMID: 30660776 PMCID: PMC6394843 DOI: 10.1016/j.bbr.2019.01.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/20/2018] [Accepted: 01/16/2019] [Indexed: 11/28/2022]
Abstract
Although there are clear sex differences in individuals with schizophrenia, preclinical research has historically favored the use of male rats for behavioral studies. The methylazoxymethanol acetate (MAM) model is a gestational disruption model of schizophrenia and has been reported to produce robust behavioral, neurophysiological and anatomical alterations in male rats; however, whether similar effects are observed in female rats is less well known. In this study, we characterize the behavioral, electrophysiological and molecular alterations induced by prenatal MAM administration in female rats while also examining the potential effects of the estrous cycle on schizophrenia-like behaviors. Specifically, MAM-treated female offspring demonstrated deficits in sensorimotor gating, latent inhibition, and social interaction, consistent with those observed in male animals. Interestingly, amphetamine-induced locomotor activity, latent inhibition, and social interaction were also affected by the estrous cycle. To examine the potential cellular mechanisms associated with these behavioral alterations, we analyzed hippocampal parvalbumin (PV) interneurons. Deficits in PV interneuron number and high-frequency gamma oscillations were disrupted in female MAM-treated rats regardless of the stage of the estrous cycle; however, alterations in PV protein expression were more prominent during metestrus/diestrus. Taken together, these data suggest that prenatal MAM exposure in female rats produces robust behavioral, molecular, and physiological deficits consistent with those observed in the male MAM model of schizophrenia. Moreover, our results also suggest that specific schizophrenia-like symptoms can also be influenced by the estrous cycle, and further emphasize the importance of sex as a biological variable when using preclinical models.
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Affiliation(s)
- Stephanie M Perez
- UT Health San Antonio, Department of Pharmacology, Center for Biomedical Neuroscience, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX, 78229, USA.
| | - Jennifer J Donegan
- UT Health San Antonio, Department of Pharmacology, Center for Biomedical Neuroscience, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX, 78229, USA.
| | - Daniel J Lodge
- UT Health San Antonio, Department of Pharmacology, Center for Biomedical Neuroscience, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX, 78229, USA.
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15
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Optogenetic induction of the schizophrenia-related endophenotype of ventral hippocampal hyperactivity causes rodent correlates of positive and cognitive symptoms. Sci Rep 2018; 8:12871. [PMID: 30150758 PMCID: PMC6110795 DOI: 10.1038/s41598-018-31163-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/07/2018] [Indexed: 01/01/2023] Open
Abstract
Pathological over-activity of the CA1 subfield of the human anterior hippocampus has been identified as a potential predictive marker for transition from a prodromal state to overt schizophrenia. Psychosis, in turn, is associated with elevated activity in the anterior subiculum, the hippocampal output stage directly activated by CA1. Over-activity in these subfields may represent a useful endophenotype to guide translationally predictive preclinical models. To recreate this endophenotype and study its causal relation to deficits in the positive and cognitive symptom domains, we optogenetically activated excitatory neurons of the ventral hippocampus (vHPC; analogous to the human anterior hippocampus), targeting the ventral subiculum. Consistent with previous studies, we found that vHPC over-activity evokes hyperlocomotion, a rodent correlate of positive symptoms. vHPC activation also impaired performance on the spatial novelty preference (SNP) test of short-term memory, regardless of whether stimulation was applied during the encoding or retrieval stage of the task. Increasing dopamine transmission with amphetamine produced hyperlocomotion, but was not associated with SNP impairments. This suggests that short-term memory impairments resulting from hippocampal over-activity likely arise independently of a hyperdopaminergic state, a finding that is consistent with the pharmaco-resistance of cognitive symptoms in patients.
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16
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Koh MT, Shao Y, Rosenzweig-Lipson S, Gallagher M. Treatment with levetiracetam improves cognition in a ketamine rat model of schizophrenia. Schizophr Res 2018; 193. [PMID: 28634087 PMCID: PMC5733713 DOI: 10.1016/j.schres.2017.06.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Imbalance in neural excitation and inhibition is associated with behavioral dysfunction in individuals with schizophrenia and at risk for this illness. We examined whether targeting increased neural activity with the antiepileptic agent, levetiracetam, would benefit memory performance in a preclinical model of schizophrenia that has been shown to exhibit hyperactivity in the hippocampus. Adult rats exposed to ketamine subchronically during late adolescence showed impaired hippocampal-dependent memory performance. Treatment with levetiracetam dose-dependently improved memory performance of the ketamine-exposed rats. In contrast, the antipsychotic medication risperidone was not effective in this assessment. Levetiracetam remained effective when administered concurrently with risperidone, supporting potential viability of adjunctive therapy with levetiracetam to treat cognitive deficits in schizophrenia patients under concurrent antipsychotic therapy. In addition to its pro-cognitive effect, levetiracetam was also effective in attenuating amphetamine-induced augmentation of locomotor activity, compatible with the need for therapeutic treatment of positive symptoms in schizophrenia.
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Affiliation(s)
- Ming Teng Koh
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
| | - Yi Shao
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 USA
| | | | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 USA,AgeneBio, Inc, 1101 E. 33rd Street, Suite C310, Baltimore, MD 21218, USA
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17
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Affiliation(s)
- Nickole Kanyuch
- Medical Scientist Training Program, The University of Maryland School of Medicine
| | - Stewart Anderson
- Lifespan Brain Institute, The Children’s Hospital of Philadelphia and The University of Pennsylvania Perelman School of Medicine,To whom correspondence should be addressed; Department of Child and Adolsecent Psychiatry and Behavioral Services, ARC 517, 3615 Civic Center Blvd, Philadelphia, PA 19104-5127, US; tel: 215-590-6527; fax: 215-590-6523; e-mail:
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18
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Donegan JJ, Tyson JA, Branch SY, Beckstead MJ, Anderson SA, Lodge DJ. Stem cell-derived interneuron transplants as a treatment for schizophrenia: preclinical validation in a rodent model. Mol Psychiatry 2017; 22:1492-1501. [PMID: 27480492 PMCID: PMC5290293 DOI: 10.1038/mp.2016.121] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 06/17/2016] [Accepted: 06/21/2016] [Indexed: 01/28/2023]
Abstract
An increasing literature suggests that schizophrenia is associated with a reduction in hippocampal interneuron function. Thus, we posit that stem cell-derived interneuron transplants may be an effective therapeutic strategy to reduce hippocampal hyperactivity and attenuate behavioral deficits in schizophrenia. Here we used a dual-reporter embryonic stem cell line to generate enriched populations of parvalbumin (PV)- or somatostatin (SST)-positive interneurons, which were transplanted into the ventral hippocampus of the methylazoxymethanol rodent model of schizophrenia. These interneuron transplants integrate within the existing circuitry, reduce hippocampal hyperactivity and normalize aberrant dopamine neuron activity. Further, interneuron transplants alleviate behaviors that model negative and cognitive symptoms, including deficits in social interaction and cognitive inflexibility. Interestingly, PV- and SST-enriched transplants produced differential effects on behavior, with PV-enriched populations effectively normalizing all the behaviors examined. These data suggest that the stem cell-derived interneuron transplants may represent a novel therapeutic strategy for schizophrenia.
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Affiliation(s)
- J J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - J A Tyson
- Department of Psychiatry, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - S Y Branch
- Department of Physiology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - M J Beckstead
- Department of Physiology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
| | - S A Anderson
- Department of Psychiatry, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - D J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX, USA
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19
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Donegan JJ, Lodge DJ. Cell-based therapies for the treatment of schizophrenia. Brain Res 2017; 1655:262-269. [PMID: 27544423 PMCID: PMC5474910 DOI: 10.1016/j.brainres.2016.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 02/08/2023]
Abstract
Schizophrenia is a devastating psychiatric disorder characterized by positive, negative and cognitive symptoms. While aberrant dopamine system function is typically associated with the positive symptoms of the disease, it is thought that this is secondary to pathology in afferent regions. Indeed, schizophrenia patients show dysregulated activity in the hippocampus and prefrontal cortex, two regions known to regulate dopamine neuron activity. These deficits in hippocampal and prefrontal cortical function are thought to result, in part, from reductions in inhibitory interneuron function in these brain regions. Therefore, it has been hypothesized that restoring interneuron function in the hippocampus and/or prefrontal cortex may be an effective treatment strategy for schizophrenia. In this article, we will discuss the evidence for interneuron pathology in schizophrenia and review recent advances in our understanding of interneuron development. Finally, we will explore how these advances have allowed us to test the therapeutic value of interneuron transplants in multiple preclinical models of schizophrenia. This article is part of a Special Issue entitled SI:StemsCellsinPsychiatry.
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Affiliation(s)
- Jennifer J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center, San Antonio, TX 78229, USA
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20
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Meyer EJ, Kirov II, Tal A, Davitz MS, Babb JS, Lazar M, Malaspina D, Gonen O. Metabolic Abnormalities in the Hippocampus of Patients with Schizophrenia: A 3D Multivoxel MR Spectroscopic Imaging Study at 3T. AJNR Am J Neuroradiol 2016; 37:2273-2279. [PMID: 27444940 DOI: 10.3174/ajnr.a4886] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/03/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Schizophrenia is well-known to be associated with hippocampal structural abnormalities. We used 1H-MR spectroscopy to test the hypothesis that these abnormalities are accompanied by NAA deficits, reflecting neuronal dysfunction, in patients compared with healthy controls. MATERIALS AND METHODS Nineteen patients with schizophrenia (11 men; mean age, 40.6 ± 10.1 years; mean disease duration, 19.5 ± 10.5 years) and 11 matched healthy controls (5 men; mean age, 33.7 ± 10.1 years) underwent MR imaging and multivoxel point-resolved spectroscopy (TE/TR, 35/1400 ms) 1H-MRS at 3T to obtain their hippocampal GM absolute NAA, Cr, Cho, and mIns concentrations. Unequal variance t tests and ANCOVA were used to compare patients with controls. Bilateral volumes from manually outlined hippocampal masks were compared by using unequal variance t tests. RESULTS Patients' average hippocampal GM Cr concentrations were 19% higher than that of controls, 8.7 ± 2.2 versus 7.4 ± 1.2 mmol/L (P < .05); showing no differences, concentrations in NAA were 8.8 ± 1.6 versus 8.7 ± 1.2 mmol/L; in Cho, 2.3 ± 0.7 versus 2.1 ± 0.3 mmol/L; and in mIns, 6.1 ± 1.5 versus 5.2 ± 0.9 (all P > .1). There was a positive correlation between mIns and Cr in patients (r = 0.57, P = .05) but not in controls. The mean bilateral hippocampal volume was ∼10% lower in patients: 7.5 ± 0.9 versus 8.4 ± 0.7 cm3 (P < .05). CONCLUSIONS These findings suggest that the hippocampal volume deficit in schizophrenia is not due to net loss of neurons, in agreement with histopathology studies but not with prior 1H-MR spectroscopy reports. Elevated Cr is consistent with hippocampal hypermetabolism, and its correlation with mIns may also suggest an inflammatory process affecting some cases; these findings may suggest treatment targets and markers to monitor them.
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Affiliation(s)
- E J Meyer
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
| | - I I Kirov
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
| | - A Tal
- Department of Chemical Physics (A.T.), Weizmann Institute of Science, Rehovot, Israel
| | - M S Davitz
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
| | - J S Babb
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
| | - M Lazar
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
| | - D Malaspina
- Department of Psychiatry (D.M.), Institute for Social and Psychiatric Initiatives, New York University School of Medicine, New York, New York
| | - O Gonen
- From the Department of Radiology (E.J.M., I.I.K., M.S.D., J.S.B., M.L., O.G.), Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging
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21
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Grace AA. Dysregulation of the dopamine system in the pathophysiology of schizophrenia and depression. Nat Rev Neurosci 2016; 17:524-32. [PMID: 27256556 PMCID: PMC5166560 DOI: 10.1038/nrn.2016.57] [Citation(s) in RCA: 629] [Impact Index Per Article: 78.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The dopamine system is unique among the brain's modulatory systems in that it has discrete projections to specific brain regions involved in motor behaviour, cognition and emotion. Dopamine neurons exhibit several activity patterns - including tonic and phasic firing - that are determined by a combination of endogenous pacemaker conductances and regulation by multiple afferent systems. Emerging evidence suggests that disruptions in these regulatory systems may underlie the pathophysiology of several psychiatric disorders, including schizophrenia and depression.
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Affiliation(s)
- Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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22
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Smucny J, Olincy A, Rojas DC, Tregellas JR. Neuronal effects of nicotine during auditory selective attention in schizophrenia. Hum Brain Mapp 2015; 37:410-21. [PMID: 26518728 DOI: 10.1002/hbm.23040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/29/2015] [Accepted: 10/18/2015] [Indexed: 12/11/2022] Open
Abstract
Although nicotine has been shown to improve attention deficits in schizophrenia, the neurobiological mechanisms underlying this effect are poorly understood. We hypothesized that nicotine would modulate attention-associated neuronal response in schizophrenia patients in the ventral parietal cortex (VPC), hippocampus, and anterior cingulate based on previous findings in control subjects. To test this hypothesis, the present study examined response in these regions in a cohort of nonsmoking patients and healthy control subjects using an auditory selective attention task with environmental noise distractors during placebo and nicotine administration. In agreement with our hypothesis, significant diagnosis (Control vs. Patient) X drug (Placebo vs. Nicotine) interactions were observed in the VPC and hippocampus. The interaction was driven by task-associated hyperactivity in patients (relative to healthy controls) during placebo administration, and decreased hyperactivity in patients after nicotine administration (relative to placebo). No significant interaction was observed in the anterior cingulate. Task-associated hyperactivity of the VPC predicted poor task performance in patients during placebo. Poor task performance also predicted symptoms in patients as measured by the Brief Psychiatric Rating Scale. These results are the first to suggest that nicotine may modulate brain activity in a selective attention-dependent manner in schizophrenia.
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Affiliation(s)
- Jason Smucny
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Ann Olincy
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Research Service, Denver VA Medical Center, Denver, Colorado
| | - Donald C Rojas
- Department of Psychology, Colorado State University, Fort Collins, Colorado
| | - Jason R Tregellas
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Research Service, Denver VA Medical Center, Denver, Colorado
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23
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Boley AM, Perez SM, Lodge DJ. A fundamental role for hippocampal parvalbumin in the dopamine hyperfunction associated with schizophrenia. Schizophr Res 2014; 157:238-43. [PMID: 24888524 PMCID: PMC4099272 DOI: 10.1016/j.schres.2014.05.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/06/2014] [Accepted: 05/09/2014] [Indexed: 11/16/2022]
Abstract
Postmortem studies in schizophrenia patients have demonstrated robust alterations in GABAergic markers throughout the neuraxis. It has been suggested that these alterations are restricted to subpopulations of interneurons, such as those containing the calcium binding protein parvalbumin. Indeed, a reduction in parvalbumin expression is a consistent observation in human postmortem studies, as well as, in a wide and diverse variety of animal models. However, it still remains to be determined whether this decrease in parvalbumin expression contributes to, or is a consequence of the disease. Here we utilize lentiviral delivered shRNA and demonstrate that a selective reduction in parvalbumin mRNA expression induces hyperactivity within the ventral hippocampus. In addition, we observe downstream increases in dopamine neuron population activity without changes in average firing rate or percent burst firing. These changes in dopamine neuron activity were associated with an enhanced locomotor response to amphetamine administration. These data therefore demonstrate that a reduction in ventral hippocampal parvalbumin expression is sufficient, in and of itself, to induce an augmented dopamine system function and behavioral hyper-responsivity to amphetamine, implicating a potential key role for parvalbumin in the pathophysiology of schizophrenia.
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Affiliation(s)
- Angela M Boley
- Department of Pharmacology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Stephanie M Perez
- Department of Pharmacology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Daniel J Lodge
- Department of Pharmacology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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24
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Tregellas JR. Neuroimaging biomarkers for early drug development in schizophrenia. Biol Psychiatry 2014; 76:111-9. [PMID: 24094513 PMCID: PMC4026337 DOI: 10.1016/j.biopsych.2013.08.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/18/2022]
Abstract
Given the relative inability of currently available antipsychotic treatments to adequately provide sustained recovery and improve quality of life for patients with schizophrenia, new treatment strategies are urgently needed. One way to improve the therapeutic development process may be an increased use of biomarkers in early clinical trials. Reliable biomarkers that reflect aspects of disease pathophysiology can be used to determine if potential treatment strategies are engaging their desired biological targets. This review evaluates three potential neuroimaging biomarkers: hippocampal hyperactivity, gamma-band deficits, and default network abnormalities. These deficits have been widely replicated in the illness, correlate with measures of positive symptoms, are consistent with models of disease pathology, and have shown initial promise as biomarkers of biological response in early studies of potential treatment strategies. Two key features of these deficits, and a guiding rationale for the focus of this review, are that the deficits are not dependent upon patients' performance of specific cognitive tasks and they have analogues in animal models of schizophrenia, greatly increasing their appeal for use as biomarkers. Using neuroimaging biomarkers such as those proposed here to establish early in the therapeutic development process if treatment strategies are having their intended biological effect in humans may facilitate development of new treatments for schizophrenia.
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Affiliation(s)
- Jason R Tregellas
- Research Service, Denver Veterans Affairs Medical Center, and Department of Psychiatry, University of Colorado Medical School, Aurora, Colorado.
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25
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Association of aberrant neural synchrony and altered GAD67 expression following exposure to maternal immune activation, a risk factor for schizophrenia. Transl Psychiatry 2014; 4:e418. [PMID: 25072323 PMCID: PMC4119228 DOI: 10.1038/tp.2014.64] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/15/2014] [Accepted: 06/16/2014] [Indexed: 12/31/2022] Open
Abstract
A failure of integrative processes within the brain, mediated via altered GABAergic inhibition, may underlie several features of schizophrenia. The present study examined, therefore, whether maternal immune activation (MIA), a risk factor for schizophrenia, altered inhibitory markers in the hippocampus and medial prefrontal cortex (mPFC), while also altering electroencephalogram (EEG) coherence between these regions. Pregnant rats were treated with saline or polyinosinic:polycytidylic acid mid-gestation. EEG depth recordings were made from the dorsal and ventral hippocampus and mPFC of male adult offspring. Glutamic decarboxylase (GAD67) levels were separately assayed in these regions using western blot. GAD67 expression was also assessed within parvalbumin-positive cells in the dorsal and ventral hippocampus using immunofluorescence alongside stereological analysis of parvalbumin-positive cell numbers. EEG coherence was reduced between the dorsal hippocampus and mPFC, but not the ventral hippocampus and mPFC, in MIA animals. Western blot and immunofluorescence analyses revealed that GAD67 expression within parvalbumin-positive cells was also reduced in the dorsal hippocampus relative to ventral hippocampus in MIA animals when compared with controls. This reduction was observed in the absence of parvalbumin-positive neuronal loss. Overall, MIA produced a selective reduction in EEG coherence between the dorsal hippocampus and mPFC that was paralleled by a similarly specific reduction in GAD67 within parvalbumin-positive cells of the dorsal hippocampus. These results suggest a link between altered inhibitory mechanisms and synchrony and, therefore point to potential mechanisms via which a disruption in neurodevelopmental processes might lead to pathophysiology associated with schizophrenia.
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Tregellas JR, Smucny J, Harris JG, Olincy A, Maharajh K, Kronberg E, Eichman LC, Lyons E, Freedman R. Intrinsic hippocampal activity as a biomarker for cognition and symptoms in schizophrenia. Am J Psychiatry 2014; 171:549-56. [PMID: 24435071 PMCID: PMC4085164 DOI: 10.1176/appi.ajp.2013.13070981] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Identification of biomarkers for cognitive dysfunction in schizophrenia is a priority for psychiatry research. Functional imaging studies suggest that intrinsic "resting state" hippocampal hyperactivity is a characteristic feature of schizophrenia. The relationships between this phenotype and symptoms of the illness, however, are largely unexplored. The authors examined resting hippocampal activity in schizophrenia patients and healthy comparison subjects and analyzed the relationship between intrinsic hippocampal activity and cognitive function in patients as measured by the MATRICS Consensus Cognitive Battery (MCCB). METHOD Twenty-eight schizophrenia patients and 28 age-matched healthy comparison subjects underwent functional "resting state" 3-T MR scanning. Hippocampal activity was extracted by group independent component analysis. Correlation analyses were used to examine the relationship between hippocampal activity and MCCB composite and domain scores in patients, as well as between hippocampal activity and positive and negative symptoms. RESULTS Greater activity of the right hippocampus at rest was observed in patients relative to comparison subjects. In patients, a significant negative correlation was observed between right hippocampal activity and composite MCCB T-score. The correlation was driven by the MCCB domains of attention/vigilance, working memory, and visual learning. Hippocampal activity was positively correlated with negative symptoms. MCCB scores were inversely correlated with negative symptoms. CONCLUSIONS These findings suggest that greater intrinsic hippocampal activity is a characteristic feature of schizophrenia that is broadly associated with cognitive dysfunction, and they support hippocampal activity as a candidate biomarker for therapeutic development.
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Belujon P, Patton MH, Grace AA. Role of the prefrontal cortex in altered hippocampal-accumbens synaptic plasticity in a developmental animal model of schizophrenia. Cereb Cortex 2014; 24:968-77. [PMID: 23236209 PMCID: PMC4047286 DOI: 10.1093/cercor/bhs380] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Schizophrenia is characterized by alterations in cortico-limbic processes believed to involve modifications in activity within the prefrontal cortex (PFC) and the hippocampus. The nucleus accumbens (NAc) integrates information from these 2 brain regions and is involved in cognitive and psychomotor functions that are disrupted in schizophrenia, indicating an important role for this structure in the pathophysiology of this disorder. In this study, we used in vivo electrophysiological recordings from the NAc and the PFC of adult rats and the MAM developmental disruption rodent model of schizophrenia to explore the influence of the medial PFC on the hippocampal-accumbens pathway. We found that, in MAM-treated rats, tetanization of hippocampal inputs to the NAc produce opposite synaptic plasticity compared with controls, which is a consequence of alterations in the hippocampal-mPFC pathway. Moreover, we show that administration of the D2-receptor-blocking antipsychotic drug sulpiride either systemically or directly into the mPFC reverses the alterations in the MAM rat. Therefore, specific disruptions in cortical and hippocampal inputs in the MAM-treated rat abnormally alter plasticity in subcortical structures. Moreover, our results suggest that, in the presence of antipsychotic drugs, the disrupted plasticities are normalized, supporting a role for this mechanism in antipsychotic drug action in schizophrenia.
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Affiliation(s)
- Pauline Belujon
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Mary H. Patton
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Chen L, Perez SM, Lodge DJ. An augmented dopamine system function is present prior to puberty in the methylazoxymethanol acetate rodent model of schizophrenia. Dev Neurobiol 2014; 74:907-17. [PMID: 24554310 DOI: 10.1002/dneu.22172] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 12/04/2013] [Accepted: 02/13/2014] [Indexed: 01/28/2023]
Abstract
Schizophrenia is a disease typically associated with an adolescent onset. Although there have been a considerable number of imaging studies investigating the transition to psychosis in prodromal patients, there are relatively few preclinical studies examining potential mechanisms that may contribute to adolescent onset. We have previously demonstrated, in the methylazoxymethanol acetate (MAM) rodent model of schizophrenia, that an enhanced activity within the ventral hippocampus may underlie the dopamine system hyperfunction, suggested to contribute to positive symptoms in patients. Here we demonstrate that the aberrant regulation of dopamine system function, in MAM-treated rats, is present prior to puberty. Furthermore, we now report that while the afferent regulation of ventral tegmental area dopamine neurons (from the hippocampus and pedunculopontine tegmental area) appears intact in preadolescent rats, the behavioral response to alterations in dopamine system function appears to be attenuated in preadolescent rats. Thus, we posit that the pathological alterations underlying psychosis may be present prior to symptom onset and that the "normal" development of the postsynaptic side of the dopamine system may underlie the transition to psychosis.
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Affiliation(s)
- Li Chen
- Department of Pharmacology & Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas; Department of Physiology, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi, China; Department of Pathophysiology, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi, China
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Evidence for impaired sound intensity processing during prepulse inhibition of the startle response in a rodent developmental disruption model of schizophrenia. J Psychiatr Res 2013; 47:1630-5. [PMID: 23932574 PMCID: PMC3786048 DOI: 10.1016/j.jpsychires.2013.07.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/21/2013] [Accepted: 07/18/2013] [Indexed: 01/01/2023]
Abstract
A number of studies have implicated disruptions in prepulse inhibition (PPI) of the startle response in both schizophrenia patients and animal models of this disorder. These disruptions are believed to reflect deficits in sensorimotor gating and are ascribed to aberrant filtering of sensory inputs leading to sensory overload and enhanced "noise" in neural structures. Here we examined auditory evoked potentials in a rodent model of schizophrenia (MAM-GD17) during an auditory PPI paradigm to better understand this phenomenon. MAM rats exhibited reductions in specific components of auditory evoked potentials in the orbitofrontal cortex and an abolition of the graded response to stimuli of differing intensities indicating deficient intensity processing in the orbitofrontal cortex. These data indicate that aberrant sensory information processing, rather than being attributable to enhanced noise in neural structures, may be better attributed to diminished evoked amplitudes resulting in a reduction in the "signal-to-noise" ratio. Therefore, the ability for sensory input to modulate the ongoing background activity may be severely disrupted in schizophrenia yielding an internal state which is insufficiently responsive to external input.
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Du Y, Grace AA. Peripubertal diazepam administration prevents the emergence of dopamine system hyperresponsivity in the MAM developmental disruption model of schizophrenia. Neuropsychopharmacology 2013; 38:1881-8. [PMID: 23612434 PMCID: PMC3746684 DOI: 10.1038/npp.2013.101] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/11/2013] [Accepted: 04/19/2013] [Indexed: 12/20/2022]
Abstract
Schizophrenia is believed to arise from an interaction of genetic predisposition and adverse environmental factors, with stress being a primary variable. We propose that alleviating anxiety produced in response to stress during a sensitive developmental period may circumvent the dopamine (DA) system alterations that may correspond to psychosis in adults. This was tested in a developmental rat model of schizophrenia based on prenatal administration of the mitotoxin methyl azoxymethanol acetate (MAM). MAM administration leads to a hyperdopaminergic state consisting of an increase in the number of DA neurons firing spontaneously, which correlates with an increased behavioral response to amphetamine. MAM-treated rats exhibited a heightened level of anxiety during adolescence. Peripubertal administration of the antianxiety agent diazepam was found to prevent the increase in DA neuron activity and blunt the behavioral hyperresponsivity to amphetamine in these rats. These data suggest that the pathophysiological factors leading to the onset of psychosis in early adulthood may be circumvented by controlling the response to stress during the peripubertal period.
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Affiliation(s)
- Yijuan Du
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Anthony A Grace
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA,Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA,Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
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Hippocampal deep brain stimulation reverses physiological and behavioural deficits in a rodent model of schizophrenia. Int J Neuropsychopharmacol 2013; 16. [PMID: 23190686 PMCID: PMC3685478 DOI: 10.1017/s1461145712001344] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Subcortical dopamine system dysregulation has been suggested to underlie the positive symptoms of schizophrenia. Recent preclinical investigations and human imaging studies have proposed that the augmented dopamine system function observed in schizophrenia patients may be secondary to aberrant hippocampal activity. Thus, we posit that the hippocampus represents a novel therapeutic target for the treatment of schizophrenia. Here we provide evidence of the effectiveness of a unique approach aimed at decreasing hippocampal function in a rodent model of schizophrenia. Specifically, in a rodent model of schizophrenia, we demonstrate that ventral hippocampal (vHipp) deep brain stimulation (DBS) can normalize aberrant dopamine neuron activity and behaviours associated with positive symptoms. In addition, we provide evidence that this approach may also be effective in restoring deficits in cognitive function, often left unaltered by conventional antipsychotic medications. Therefore, we have provided initial preclinical evidence demonstrating the feasibility of hippocampal DBS as a potential novel approach for the treatment of schizophrenia.
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Ewing SG, Winter C. The ventral portion of the CA1 region of the hippocampus and the prefrontal cortex as candidate regions for neuromodulation in schizophrenia. Med Hypotheses 2013; 80:827-32. [PMID: 23583328 DOI: 10.1016/j.mehy.2013.03.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 03/17/2013] [Indexed: 02/08/2023]
Abstract
Existing antipsychotic drugs are most effective in the treatment of the positive symptoms of schizophrenia. However, they are associated with considerable side effects and have relatively low efficacy. Diminished inhibitory control in the hippocampus has been suggested to lead to hyperactivation of the dopamine system thus underpinning the dopamine-dependent psychosis associated with schizophrenia. Similarly, diminished inhibitory control is thought to underpin the cortical disruption associated with the cognitive dysfunctions. Impairment of a specific class of parvalbumin-positive inhibitory interneuron has been consistently identified in the prefrontal cortex and hippocampus of schizophrenics. Thus, this impairment common to both regions, may subserve these distinct symptom domains. Deep brain stimulation has been suggested to act, at least in part, through the modulation of interneuron function and here we propose the prefrontal cortex and hippocampus as potential targets for neuromodulatory intervention in the treatment of schizophrenia. Further, we specifically consider whether multiple targets and multiple neuromodulatory approaches may be necessary in the treatment of this multi-faceted disease. Finally we propose that deep brain stimulation of the ventral protion of the CA1 region of the hippocampus may be the most promising single target for neuromodulation in schizophrenia.
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Affiliation(s)
- Samuel G Ewing
- Bereich Experimentelle Psychiatrie, Universitätsklinik Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.
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Smucny J, Rojas DC, Eichman LC, Tregellas JR. Neural effects of auditory distraction on visual attention in schizophrenia. PLoS One 2013; 8:e60606. [PMID: 23560100 PMCID: PMC3613360 DOI: 10.1371/journal.pone.0060606] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/28/2013] [Indexed: 11/19/2022] Open
Abstract
Sensory flooding, particularly during auditory stimulation, is a common problem for patients with schizophrenia. The functional consequences of this impairment during cross-modal attention tasks, however, are unclear. The purpose of this study was to examine how auditory distraction differentially affects task-associated response during visual attention in patients and healthy controls. To that end, 21 outpatients with schizophrenia and 23 healthy comparison subjects performed a visual attention task in the presence or absence of distracting, environmentally relevant "urban" noise while undergoing functional magnetic resonance imaging at 3T. The task had two conditions (difficult and easy); task-related neural activity was defined as difficult - easy. During task performance, a significant distraction (noise or silence) by group (patient or control) interaction was observed in the left dorsolateral prefrontal cortex, right hippocampus, left temporoparietal junction, and right fusiform gyrus, with patients showing relative hypoactivation during noise compared to controls. In patients, the ability to recruit the dorsolateral prefrontal cortex during the task in noise was negatively correlated with the effect of noise on reaction time. Clinically, the ability to recruit the fusiform gyrus during the task in noise was negatively correlated with SANS affective flattening score, and hippocampal recruitment during the task in noise was positively correlated with global functioning. In conclusion, schizophrenia may be associated with abnormalities in neural response during visual attention tasks in the presence of cross-modal noise distraction. These response differences may predict global functioning in the illness, and may serve as a biomarker for therapeutic development.
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Affiliation(s)
- Jason Smucny
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Donald C. Rojas
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Research Service, Denver VA Medical Center, Denver, Colorado, United States of America
| | - Lindsay C. Eichman
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Research Service, Denver VA Medical Center, Denver, Colorado, United States of America
| | - Jason R. Tregellas
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- Research Service, Denver VA Medical Center, Denver, Colorado, United States of America
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Ewing SG, Grace AA. Deep brain stimulation of the ventral hippocampus restores deficits in processing of auditory evoked potentials in a rodent developmental disruption model of schizophrenia. Schizophr Res 2013; 143:377-83. [PMID: 23269227 PMCID: PMC3547127 DOI: 10.1016/j.schres.2012.11.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/18/2012] [Accepted: 11/20/2012] [Indexed: 12/30/2022]
Abstract
Existing antipsychotic drugs are most effective at treating the positive symptoms of schizophrenia but their relative efficacy is low and they are associated with considerable side effects. In this study deep brain stimulation of the ventral hippocampus was performed in a rodent model of schizophrenia (MAM-E17) in an attempt to alleviate one set of neurophysiological alterations observed in this disorder. Bipolar stimulating electrodes were fabricated and implanted, bilaterally, into the ventral hippocampus of rats. High frequency stimulation was delivered bilaterally via a custom-made stimulation device and both spectral analysis (power and coherence) of resting state local field potentials and amplitude of auditory evoked potential components during a standard inhibitory gating paradigm were examined. MAM rats exhibited alterations in specific components of the auditory evoked potential in the infralimbic cortex, the core of the nucleus accumbens, mediodorsal thalamic nucleus, and ventral hippocampus in the left hemisphere only. DBS was effective in reversing these evoked deficits in the infralimbic cortex and the mediodorsal thalamic nucleus of MAM-treated rats to levels similar to those observed in control animals. In contrast stimulation did not alter evoked potentials in control rats. No deficits or stimulation-induced alterations were observed in the prelimbic and orbitofrontal cortices, the shell of the nucleus accumbens or ventral tegmental area. These data indicate a normalization of deficits in generating auditory evoked potentials induced by a developmental disruption by acute high frequency, electrical stimulation of the ventral hippocampus.
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Affiliation(s)
- Samuel G. Ewing
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA,Corresponding author (Samuel G. Ewing)
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA
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Sato K. Disruption of spine homeostasis causes dopaminergic compensatory up-regulation, resulting in schizophrenia. Med Hypotheses 2012; 79:304-7. [DOI: 10.1016/j.mehy.2012.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/03/2012] [Accepted: 05/10/2012] [Indexed: 10/28/2022]
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Antipsychotic drugs rapidly induce dopamine neuron depolarization block in a developmental rat model of schizophrenia. J Neurosci 2011; 31:12330-8. [PMID: 21865475 DOI: 10.1523/jneurosci.2808-11.2011] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Repeated administration of antipsychotic drugs to normal rats has been shown to induce a state of dopamine neuron inactivation known as depolarization block, which correlates with the ability of the drugs to exhibit antipsychotic efficacy and extrapyramidal side effects in schizophrenia patients. Nonetheless, in normal rats depolarization block requires weeks of antipsychotic drug administration, whereas schizophrenia patients exhibit initial effects soon after initiating antipsychotic drug treatment. We now report that, in a developmental disruption rat model of schizophrenia [methyl-azoxymethanol acetate (20 mg/kg, i.p.) injected into G17 pregnant female rats, with offspring tested as adults], the extant hyperdopaminergic state combines with the excitatory actions of a first- (haloperidol; 0.6 mg/kg, i.p.) and a second- (sertindole; 2.5 mg/kg, i.p.) generation antipsychotic drug to rapidly induce depolarization block in ventral tegmental area dopamine neurons. Acute injection of either antipsychotic drug induced an immediate reduction in the number of spontaneously active dopamine neurons (cells per electrode track; termed population activity). Repeated administration of either antipsychotic drug for 1, 3, 7, 15, and 21 d continued to reduce dopamine neuron population activity. Both acute and repeated effects on population activity were reversed by acute apomorphine injections, which is consistent with the reversal of dopamine neuron depolarization block. Although this action may account for the effects of D2 antagonist drugs on alleviating psychosis and the lack of development of tolerance in humans, the drugs appear to do so by inducing an offsetting deficit rather than attacking the primary pathology present in schizophrenia.
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37
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Lodge DJ, Grace AA. Hippocampal dysregulation of dopamine system function and the pathophysiology of schizophrenia. Trends Pharmacol Sci 2011; 32:507-13. [PMID: 21700346 DOI: 10.1016/j.tips.2011.05.001] [Citation(s) in RCA: 228] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 05/04/2011] [Accepted: 05/06/2011] [Indexed: 01/11/2023]
Abstract
Substantial evidence suggests that psychosis in schizophrenia is associated with dysregulation of subcortical dopamine system function. Here we examine evidence that this dysregulation is secondary to hyperactivity within hippocampal subfields. Enhanced hippocampal activity has been reported in preclinical models and in schizophrenia patients. Moreover, this hippocampal hyperactivity is correlated with enhanced dopamine neuron activity and positive symptoms, respectively. Thus, restoration of hippocampal function could provide a more effective therapeutic approach than current therapeutics based on blockade of dopamine D2 receptors. Indeed, initial studies demonstrate that allosteric modulation of the α5GABA(A) receptor can decrease aberrant dopamine signaling and associated behaviors in a verified rodent model of psychosis.
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Affiliation(s)
- Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Grace AA. Dopamine system dysregulation by the hippocampus: implications for the pathophysiology and treatment of schizophrenia. Neuropharmacology 2011; 62:1342-8. [PMID: 21621548 DOI: 10.1016/j.neuropharm.2011.05.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 05/11/2011] [Accepted: 05/13/2011] [Indexed: 11/19/2022]
Abstract
For decades, the predominant hypothesis of schizophrenia centered on dysfunctions of the dopamine system. However, recent evidence now suggests that the dopamine system may be "normal" in its configuration, but instead is regulated abnormally by modulatory processes. Convergent studies in animals and in humans have now focused on the hippocampus as a central component in the generation of psychosis and possibly other symptom states in schizophrenia. Thus, activity in the ventral hippocampus has been shown to regulate dopamine neuron responsivity by controlling the number of dopamine neurons that can be phasically activated by stimuli. In this way, this structure determines the gain of the dopamine signal in response to stimuli. However, in schizophrenia, the hippocampus appears to be hyper-active, possibly due to attenuation of function of inhibitory interneurons. As a result, the dopamine system is driven into an overly responsive state. Current medications have focused on blockade of overstimulated dopamine receptors; however, this now appears to be several synapses downstream from the pathological antecedent. Therapeutic approaches that focus on normalizing hippocampal function may prove to be more effective treatment avenues for the schizophrenia patient.
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Affiliation(s)
- Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, 458 Crawford Hall, Pittsburgh, PA 15260, USA.
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Poor visual fixation in children and its possible role in attention deficit disorder (ADD). ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.clch.2010.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
Dysfunction within the dopamine system has been the predominant hypothesized cause of schizophrenia for some time; however, there is little anatomical or postmortem evidence showing that the roots of this disorder are to be found within the dopaminergic neurons. Instead, the dopamine system appears to be dysregulated due to pathological influences from other structures. Recent postmortem and imaging studies have looked to the hippocampus as a potential site of this pathology. Our studies using a developmental animal model of schizophrenia found hyperactivity in the hippocampus likely drives the disruption in dopamine system function. This overactivity appears to be due to the functional loss of short axon interneurons that control the activity of the primary output neurons of the hippocampus. These data suggest that a more effective treatment of schizophrenia may be to normalize hippocampal function rather than block dopamine receptors. Moreover, given the high sensitivity of the hippocampus to stress-induced damage and the fact that stress is a risk factor for schizophrenia, controlling stress in the premorbid state may be an effective preventative measure to circumvent the transition to psychosis.
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Affiliation(s)
- Anthony A. Grace
- Departments of Neuroscience, Psychiatry, and Psychology,
University of Pittsburgh
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Abstract
3-(2,4-Dimethoxybenzylidene)-anabaseine (DMXB-A) is a partial agonist at alpha7-nicotinic acetylcholine receptors and is now in early clinical development for treatment of deficits in neurocognition and sensory gating in schizophrenia. During its initial phase 2 test, functional magnetic resonance imaging (fMRI) studies were conducted to determine whether the drug had its intended effect on hippocampal inhibitory interneurons. Increased hemodynamic activity in the hippocampus in schizophrenia is found during many tasks, including smooth pursuit eye movements, and may reflect inhibitory dysfunction. Placebo and two doses of drug were administered in a random, double-blind crossover design. After the morning drug/placebo ingestion, subjects underwent fMRI while performing a smooth pursuit eye movement task. Data were analyzed from 16 nonsmoking patients, including 7 women and 9 men. The 150-mg dose of DMXB-A, compared with placebo, diminished the activity of the hippocampus during pursuit eye movements, but the 75-mg dose was ineffective. The effect at the 150-mg dose was negatively correlated with plasma drug levels. The findings are consistent with the previously established function of alpha7-nicotinic receptors on inhibitory interneurons in the hippocampus and with genetic evidence for deficits in these receptors in schizophrenia. Imaging of drug response is useful in planning future clinical tests of this compound and other nicotinic agonists for schizophrenia.
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Dopamine system dysregulation by the ventral subiculum as the common pathophysiological basis for schizophrenia psychosis, psychostimulant abuse, and stress. Neurotox Res 2010; 18:367-76. [PMID: 20143199 DOI: 10.1007/s12640-010-9154-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/21/2010] [Accepted: 01/21/2010] [Indexed: 01/08/2023]
Abstract
The dopamine system is under multiple forms of regulation, and in turn provides effective modulation of system responses. Dopamine neurons are known to exist in several states of activity. The population activity, or the proportion of dopamine neurons firing spontaneously, is controlled by the ventral subiculum of the hippocampus. In contrast, burst firing, which is proposed to be the behaviorally salient output of the dopamine system, is driven by the brainstem pedunculopontine tegmentum (PPTg). When an animal is exposed to a behaviorally salient stimulus, the PPTg elicits a burst of action potentials in the dopamine neurons. However, this bursting only occurs in the portion of the dopamine neuron population that is firing spontaneously. This proportion is regulated by the ventral subiculum. Therefore, the ventral subiculum provides the gain, or the amplification factor, for the behaviorally salient stimulus. The ventral subiculum itself is proposed to carry information related to the environmental context. Thus, the ventral subiculum will adjust the responsivity of the dopamine system based on the needs of the organism and the characteristics of the environment. However, this finely tuned system can be disrupted in disease states. In schizophrenia, a disruption of interneuronal regulation of the ventral subiculum is proposed to lead to an overdrive of the dopamine system, rendering the system in a constant hypervigilant state. Moreover, amphetamine sensitization and stressors also appear to cause an abnormal dopaminergic drive. Such an interaction could underlie the risk factors of drug abuse and stress in the precipitation of a psychotic event. On the other hand, this could point to the ventral subiculum as an effective site of therapeutic intervention in the treatment or even the prevention of schizophrenia.
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Freedman R, Goldowitz D. Studies on the hippocampal formation: From basic development to clinical applications: Studies on schizophrenia. Prog Neurobiol 2009; 90:263-75. [PMID: 19853005 DOI: 10.1016/j.pneurobio.2009.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 07/31/2009] [Accepted: 10/09/2009] [Indexed: 10/20/2022]
Abstract
The hippocampal formation plays a critical role in cognitive function. The developmental events that shape the hippocampal formation are continuing to be elucidated and their implications for brain function are emerging as well as applying those advances to interventions that have important possibilities for the treatment of brain dysfunction. The story told in this chapter is about the use of the in oculo transplant method to illuminate intrinsic and extrinsic features that underlie the development of the dentate gyrus and adjacent hippocampus and the role of one molecule in the hippocampus and schizophrenia. Schizophrenia, originally conceptualized as a dysfunction in dopaminergic neurotransmission, is now known to involve multiple neuronal systems. Dysfunction of hippocampal neurons is emerging as one of its signature pathological features. Basic insights into the development and function of hippocampal interneurons form the basis of a new treatment initiative for this illness. Evidence for the role of the alpha 7-nicotinic acetylcholine receptor in the development and function of these neurons in rodents has led to human trials of nicotinic agonists for cognitive dysfunction in schizophrenia and the possibility of improving hippocampal development in children at risk for schizophrenia by perinatal supplementation with choline, which can act as an alpha 7-nicotinic acetylcholine receptor agonist.
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Affiliation(s)
- Robert Freedman
- Dept Psychiatry, University of Colorado at Denver and Health Sciences Center, 13001 E. 17th Pl., Campus Box F546, Aurora, CO 800045, USA
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Schobel SA, Kelly MA, Corcoran CM, Van Heertum K, Seckinger R, Goetz R, Friedman JH, Malaspina D. Anterior hippocampal and orbitofrontal cortical structural brain abnormalities in association with cognitive deficits in schizophrenia. Schizophr Res 2009; 114:110-8. [PMID: 19683896 PMCID: PMC2743795 DOI: 10.1016/j.schres.2009.07.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 07/16/2009] [Accepted: 07/20/2009] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Numerous studies have implicated the hippocampus and prefrontal cortex in schizophrenia. However, precisely which subregions of the hippocampus and prefrontal cortex are abnormal remain unknown. Our study goal was to investigate the structure of the anterior hippocampus, posterior hippocampus, dorsolateral prefrontal cortex (DLPFC), and orbitofrontal cortex (OFC) simultaneously in thirty-eight patients with schizophrenia and twenty-nine controls to determine which of these subregions are abnormal in schizophrenia. As an exploratory study goal, we investigated the relation of neurocognition to brain structure in schizophrenia patients. METHOD We generated detailed structural magnetic resonance imaging data and compared hippocampal and prefrontal subregional structural brain volumes between schizophrenia and control groups. We obtained a neurocognitive test battery in schizophrenia patients and studied the association of abnormal brain structures to neurocognition. RESULTS Structural brain abnormalities were pinpointed to the left anterior hippocampus and left OFC in schizophrenia patients, which were both significantly reduced in volume. The DLPFC and posterior hippocampus, though numerically decreased in volume, were not significantly decreased. Anterior hippocampal volumes were more strongly associated with OFC volumes in schizophrenia patients compared to controls. By contrast, DLPFC volume was unrelated to anterior or posterior hippocampal volume. Both the anterior hippocampus and OFC were independently related to cognitive abnormalities common in schizophrenia, including indices of verbal, language, and executive functions. The DLPFC and posterior hippocampal volumes were unrelated to cognitive measures. CONCLUSIONS These findings highlight related abnormalities of the anterior hippocampus and OFC in schizophrenia, which may shed light on the pathophysiology of the disorder.
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Affiliation(s)
- Scott A. Schobel
- Center for Prevention and Evaluation (COPE), New York State Psychiatric Institute, New York, N.Y.,Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y
| | - Meredith A. Kelly
- Center for Prevention and Evaluation (COPE), New York State Psychiatric Institute, New York, N.Y
| | - Cheryl M. Corcoran
- Center for Prevention and Evaluation (COPE), New York State Psychiatric Institute, New York, N.Y.,Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y
| | - Kristin Van Heertum
- Center for Prevention and Evaluation (COPE), New York State Psychiatric Institute, New York, N.Y.,Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y
| | - Regina Seckinger
- Center for Prevention and Evaluation (COPE), New York State Psychiatric Institute, New York, N.Y.,Department of Psychiatry, New York University, New York, N.Y
| | - Ray Goetz
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y.,Department of Psychiatry, New York University, New York, N.Y
| | - Jill Harkavy Friedman
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y
| | - Dolores Malaspina
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, N.Y.,Department of Psychiatry, New York University, New York, N.Y
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A loss of parvalbumin-containing interneurons is associated with diminished oscillatory activity in an animal model of schizophrenia. J Neurosci 2009; 29:2344-54. [PMID: 19244511 DOI: 10.1523/jneurosci.5419-08.2009] [Citation(s) in RCA: 360] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Decreased GABAergic signaling is among the more robust pathologies observed postmortem in schizophrenia; however, the functional consequences of this deficit are still largely unknown. Here, we demonstrate, in a verified animal model of schizophrenia, that a reduced expression of parvalbumin (PV)-containing interneurons is correlated with a reduction in coordinated neuronal activity during task performance in freely moving rats. More specifically, methylazoxymethanol acetate (MAM)-treated rats display a decreased density of parvalbumin-positive interneurons throughout the medial prefrontal cortex (mPFC) and ventral (but not dorsal) subiculum of the hippocampus. Furthermore, the reduction in interneuron functionality is correlated with a significantly reduced gamma-band response to a conditioned tone during a latent inhibition paradigm. Finally, deficits in mPFC and ventral hippocampal oscillatory activity are associated with an impaired behavioral expression of latent inhibition in MAM-treated rats. Thus, we propose that a decrease in intrinsic GABAergic signaling may be responsible, at least in part, for the prefrontal and hippocampal hypofunctionality observed during task performance, which is consistently observed in animal models as well as in schizophrenia in humans. In addition, a deficit in intrinsic GABAergic signaling may be the origin of the hippocampal hyperactivity purported to underlie the dopamine dysfunction in psychosis. Such information is central to gaining a better understanding of the disease pathophysiology and alternate pharmacotherapeutic approaches.
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Lodge DJ, Grace AA. Gestational methylazoxymethanol acetate administration: a developmental disruption model of schizophrenia. Behav Brain Res 2009; 204:306-12. [PMID: 19716984 DOI: 10.1016/j.bbr.2009.01.031] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/22/2009] [Accepted: 01/23/2009] [Indexed: 12/15/2022]
Abstract
Animal models are critical for the study of psychiatric disorders since they allow the use of invasive methods that cannot be used for ethical reasons in humans. Currently there are three general models of schizophrenia; (i) those produced with acute pharmacological intervention (i.e. MK-801, ketamine, PCP and amphetamine), (ii) genetic models (i.e. mutant DISC-1, D(2)-R over expression) and (iii) developmental disruption models (i.e. MAM, neonatal ventral hippocampal lesion, isolation rearing, maternal infection). Here we review evidence for the validity of gestational (day 17) MAM administration as a developmental disruption rodent model of schizophrenia. Offspring from MAM-treated dams are reported to display deficits consistent with those observed in schizophrenia patients, including anatomical changes, behavioral deficits and altered neuronal information processing. Thus gestational MAM administration has been demonstrated to induce a pathodevelopmental process leading to neuroanatomical and behavioral phenotypes consistent with that observed in schizophrenia in humans.
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Affiliation(s)
- Daniel J Lodge
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, A210 Langley Hall, Pittsburgh, PA 15260, USA.
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Shur S, Shamay-Tsoory SG, Levkovitz Y. Integration of emotional and cognitive aspects of theory of mind in schizophrenia and its relation to prefrontal neurocognitive performance. Cogn Neuropsychiatry 2008; 13:472-90. [PMID: 19048440 DOI: 10.1080/13546800802490034] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION There is substantial evidence that patients with schizophrenia present with impaired Theory of Mind (ToM). Whereas previous studies have focused on general ToM abilities, the present study is aimed at testing the underlying behavioural and neurocognitive mechanisms of the impaired integration of affective and cognitive aspects of ToM (the integration of emotional information with mentalising) in patients with schizophrenia. METHODS Twenty-six patients with schizophrenia and 35 healthy controls were tested on two ToM tasks involving the integration of affective and cognitive ToM abilities: "Faux Pas" and "reading the mind in the eyes" tasks. To assess the neurocognitive bases of impaired ToM, the ID/ED test (intradimensional/extradimensional shifting test from the CANTAB) was administered. RESULTS Patients performed poorly on both the cognitive-affective integration ToM tasks and the ID/ED task as compared to controls. Furthermore, patients' ToM scores were selectively correlated with the reversal trials, which are believed to be associated with orbitofrontal functioning. In addition, more than 50% of the variance in recognising and understanding Faux Pas could be explained by patients' symptomatology. Performance on orbitofrontal related tasks was correlated with subjects' Faux Pas scores in the patients group, but not in the healthy control group. CONCLUSIONS Schizophrenic patients appear to have considerable impairment in affective and cognitive ToM integration, which may be related to orbitofrontal dysfunction. These results are in line with previous findings regarding empathy and the importance of the orbitofrontal area in the integration of cognition and affect.
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Affiliation(s)
- Syvan Shur
- Department of Psychology and Brain and Behaviour Center, University of Haifa, Haifa, Israel.
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Summary of the 1st Schizophrenia International Research Society Conference oral sessions, Venice, Italy, June 21-25, 2008: the rapporteur reports. Schizophr Res 2008; 105:289-383. [PMID: 18819775 DOI: 10.1016/j.schres.2008.08.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Schizophrenia International Research Society held its first scientific conference in Venice, Italy, June 21 to 25th, 2008. A wide range of controversial topics were presented in overlapping and plenary oral sessions. These included new genetic studies, controversies about early detection of schizophrenia and the prodrome, treatment issues, clinical characteristics, cognition, neuropathology and neurophysiology, other etiological considerations, substance abuse co-morbidity, and animal models for investigating disease etiology and for use as targets in drug studies. Young investigators in the field were awarded travel grants to participate in the congress and one of their roles was to summarize the oral sessions and subsequent discussions. The reports that follow are the culmination of this work produced by 30 young investigators who attended the congress. It is hoped that these summaries will be useful synopses of what actually occurred at the congress for those who did not attend each session or were unable to be present. The abstracts of all presentations, as submitted by the authors a few months prior, were previously published as supplement 2 to volume 102/1-3, June 2008.
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Shamay-Tsoory SG, Shur S, Barcai-Goodman L, Medlovich S, Harari H, Levkovitz Y. Dissociation of cognitive from affective components of theory of mind in schizophrenia. Psychiatry Res 2007; 149:11-23. [PMID: 17107716 DOI: 10.1016/j.psychres.2005.10.018] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 09/15/2005] [Accepted: 10/21/2005] [Indexed: 11/23/2022]
Abstract
Patients suffering from schizophrenia show impaired emotional and social behavior, such as misinterpretation of social situations and lack of theory of mind. However, there is conflicting evidence regarding their ability to perform on theory of mind tasks. Based on previous findings with patients suffering from prefrontal damage, the present study suggests that the behavioral deficit of schizophrenic patients may be due to impaired 'affective theory of mind' abilities, rather than to a general impairment in theory of mind. To test this hypothesis we assessed the ability of 22 schizophrenic patients and 55 age-matched healthy controls, to judge first and second order affective vs. cognitive mental state attribution, based on eye gaze. The relationships between negative and positive symptoms of schizophrenia, and affective and cognitive theory of mind were also assessed. Results indicated that while healthy controls made fewer errors on affective as compared to cognitive theory of mind conditions, schizophrenic patients showed a less prominent trend. Although the pattern of reaction time did not differ significantly between groups, the patients made significantly more errors in the affective conditions, as compared to controls. Furthermore, correlation analysis indicated that impaired affective theory of mind in these patients correlated with their level of negative symptoms. These results indicate that individuals with high level of negative symptoms of schizophrenia may demonstrate selective impairment in their ability to attribute affective mental states. These findings offer new insight into the affective facets of social behavior that may underlie the profound behavioral disturbances observed in schizophrenia.
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Affiliation(s)
- Simone G Shamay-Tsoory
- Department of Psychology and Brain and Behavior Center, University of Haifa, Haifa 31905, Israel.
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Kohno T, Shiga T, Kusumi I, Matsuyama T, Kageyama H, Katoh C, Koyama T, Tamaki N. Left temporal perfusion associated with suspiciousness score on the Brief Psychiatric Rating Scale in schizophrenia. Psychiatry Res 2006; 147:163-71. [PMID: 16959474 DOI: 10.1016/j.pscychresns.2006.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/25/2006] [Accepted: 01/29/2006] [Indexed: 11/21/2022]
Abstract
We evaluated the relationship between regional cerebral blood flow (rCBF) and clinical symptoms in patients with schizophrenia. Single photon emission computed tomography with N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) was used to study 29 patients with schizophrenia. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). We examined the correlation between rCBF and each BPRS item score using Statistical Parametric Mapping software. Corrected P-values < 0.05 were considered as statistically significant. The suspiciousness score on the BPRS was positively correlated with rCBF in the left inferior temporal gyrus. There was no significant correlation between rCBF and any other items of the BPRS. There was no significant correlation between rCBF and chlorpromazine-equivalent dosage. This analysis permits the quantitative assessment of the severity of persecutory delusions in relation to left temporal perfusion in patients with schizophrenia.
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Affiliation(s)
- Tomoya Kohno
- Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo 060-8638, Japan.
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