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Damme KSF, Alloy LB, Young CB, Kelley NJ, Chein J, Ng TH, Titone MK, Black CL, Nusslock R. Amygdala subnuclei volume in bipolar spectrum disorders: Insights from diffusion-based subsegmentation and a high-risk design. Hum Brain Mapp 2020; 41:3358-3369. [PMID: 32386113 PMCID: PMC7375099 DOI: 10.1002/hbm.25021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 04/06/2020] [Accepted: 04/13/2020] [Indexed: 12/31/2022] Open
Abstract
Amygdala abnormalities are widely documented in bipolar spectrum disorders (BSD). Amygdala volume typically is measured after BSD onset; thus, it is not known whether amygdala abnormalities predict BSD risk or relate to the disorder. Additionally, past literature often treated the amygdala as a homogeneous structure, and did not consider its distinct subnuclei and their differential connectivity to other brain regions. To address these issues, we used a behavioral high‐risk design and diffusion‐based subsegmentation to examine amygdala subnuclei among medication‐free individuals with, and at risk for, BSD. The behavioral high‐risk design (N = 114) included low‐risk (N = 37), high‐risk (N = 47), and BSD groups (N = 30). Diffusion‐based subsegmentation of the amygdala was conducted to determine whether amygdala volume differences related to particular subnuclei. Individuals with a BSD diagnosis showed greater whole, bilateral amygdala volume compared to Low‐Risk individuals. Examination of subnuclei revealed that the BSD group had larger volumes compared to the High‐Risk group in both the left medial and central subnuclei, and showed larger volume in the right lateral subnucleus compared to the Low‐Risk group. Within the BSD group, specific amygdala subnuclei volumes related to time since first episode onset and number of lifetime episodes. Taken together, whole amygdala volume analyses replicated past findings of enlargement in BSD, but did not detect abnormalities in the high‐risk group. Examination of subnuclei volumes detected differences in volume between the high‐risk and BSD groups that were missed in the whole amygdala volume. Results have implications for understanding amygdala abnormalities among individuals with, and at risk for, a BSD.
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Affiliation(s)
| | - Lauren B Alloy
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
| | - Christina B Young
- Department of Psychology, Northwestern University, Evanston, Illinois, USA.,Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Nicholas J Kelley
- Department of Psychology, Northwestern University, Evanston, Illinois, USA.,School of Psychology, University of Southampton, Southampton, UK
| | - Jason Chein
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
| | - Tommy H Ng
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
| | - Madison K Titone
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
| | - Chelsea L Black
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA.,Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Robin Nusslock
- Department of Psychology, Northwestern University, Evanston, Illinois, USA
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2
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Bobilev AM, Perez JM, Tamminga CA. Molecular alterations in the medial temporal lobe in schizophrenia. Schizophr Res 2020; 217:71-85. [PMID: 31227207 DOI: 10.1016/j.schres.2019.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/29/2019] [Accepted: 06/01/2019] [Indexed: 11/30/2022]
Abstract
The medial temporal lobe (MTL) and its individual structures have been extensively implicated in schizophrenia pathophysiology, with considerable efforts aimed at identifying structural and functional differences in this brain region. The major structures of the MTL for which prominent differences have been revealed include the hippocampus, the amygdala and the superior temporal gyrus (STG). The different functions of each of these regions have been comprehensively characterized, and likely contribute differently to schizophrenia. While neuroimaging studies provide an essential framework for understanding the role of these MTL structures in various aspects of the disease, ongoing efforts have sought to employ molecular measurements in order to elucidate the biology underlying these macroscopic differences. This review provides a summary of the molecular findings in three major MTL structures, and discusses convergent findings in cellular architecture and inter-and intra-cellular networks. The findings of this effort have uncovered cell-type, network and gene-level specificity largely unique to each brain region, indicating distinct molecular origins of disease etiology. Future studies should test the functional implications of these molecular changes at the circuit level, and leverage new advances in sequencing technology to further refine our understanding of the differential contribution of MTL structures to schizophrenia.
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Affiliation(s)
- Anastasia M Bobilev
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
| | - Jessica M Perez
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
| | - Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
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3
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In vivo estimation of normal amygdala volume from structural MRI scans with anatomical-based segmentation. Surg Radiol Anat 2017; 40:145-157. [DOI: 10.1007/s00276-017-1915-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 08/23/2017] [Indexed: 01/23/2023]
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4
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Dynamic Changes in Amygdala Psychophysiological Connectivity Reveal Distinct Neural Networks for Facial Expressions of Basic Emotions. Sci Rep 2017; 7:45260. [PMID: 28345642 PMCID: PMC5366904 DOI: 10.1038/srep45260] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 02/23/2017] [Indexed: 12/12/2022] Open
Abstract
The quest to characterize the neural signature distinctive of different basic emotions has recently come under renewed scrutiny. Here we investigated whether facial expressions of different basic emotions modulate the functional connectivity of the amygdala with the rest of the brain. To this end, we presented seventeen healthy participants (8 females) with facial expressions of anger, disgust, fear, happiness, sadness and emotional neutrality and analyzed amygdala's psychophysiological interaction (PPI). In fact, PPI can reveal how inter-regional amygdala communications change dynamically depending on perception of various emotional expressions to recruit different brain networks, compared to the functional interactions it entertains during perception of neutral expressions. We found that for each emotion the amygdala recruited a distinctive and spatially distributed set of structures to interact with. These changes in amygdala connectional patters characterize the dynamic signature prototypical of individual emotion processing, and seemingly represent a neural mechanism that serves to implement the distinctive influence that each emotion exerts on perceptual, cognitive, and motor responses. Besides these differences, all emotions enhanced amygdala functional integration with premotor cortices compared to neutral faces. The present findings thus concur to reconceptualise the structure-function relation between brain-emotion from the traditional one-to-one mapping toward a network-based and dynamic perspective.
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5
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Aghamohammadi-Sereshki A, Huang Y, Olsen F, Malykhin NV. In vivo quantification of amygdala subnuclei using 4.7 T fast spin echo imaging. Neuroimage 2017; 170:151-163. [PMID: 28288907 DOI: 10.1016/j.neuroimage.2017.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 03/03/2017] [Accepted: 03/07/2017] [Indexed: 11/15/2022] Open
Abstract
The amygdala (AG) is an almond-shaped heterogeneous structure located in the medial temporal lobe. The majority of previous structural Magnetic Resonance Imaging (MRI) volumetric methods for AG measurement have so far only been able to examine this region as a whole. In order to understand the role of the AG in different neuropsychiatric disorders, it is necessary to understand the functional role of its subnuclei. The main goal of the present study was to develop a reliable volumetric method to delineate major AG subnuclei groups using ultra-high resolution high field MRI. 38 healthy volunteers (15 males and 23 females, 21-60 years of age) without any history of medical or neuropsychiatric disorders were recruited for this study. Structural MRI datasets were acquired at 4.7 T Varian Inova MRI system using a fast spin echo (FSE) sequence. The AG was manually segmented into its five major anatomical subdivisions: lateral (La), basal (B), accessory basal (AB) nuclei, and cortical (Co) and centromedial (CeM) groups. Inter-(intra-) rater reliability of our novel volumetric method was assessed using intra-class correlation coefficient (ICC) and Dice's Kappa. Our results suggest that reliable measurements of the AG subnuclei can be obtained by image analysts with experience in AG anatomy. We provided a step-by-step segmentation protocol and reported absolute and relative volumes for the AG subnuclei. Our results showed that the basolateral (BLA) complex occupies seventy-eight percent of the total AG volume, while CeM and Co groups occupy twenty-two percent of the total AG volume. Finally, we observed no hemispheric effects and no gender differences in the total AG volume and the volumes of its subnuclei. Future applications of this method will help to understand the selective vulnerability of the AG subnuclei in neurological and psychiatric disorders.
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Affiliation(s)
| | - Yushan Huang
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Fraser Olsen
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Nikolai V Malykhin
- Neuroscience and Mental Health Institute, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
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6
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Bernstein HG, Ortmann A, Dobrowolny H, Steiner J, Brisch R, Gos T, Bogerts B. Bilaterally reduced claustral volumes in schizophrenia and major depressive disorder: a morphometric postmortem study. Eur Arch Psychiatry Clin Neurosci 2016; 266:25-33. [PMID: 25822416 DOI: 10.1007/s00406-015-0597-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/23/2015] [Indexed: 12/27/2022]
Abstract
Multiple brain structural abnormalities have been reported in schizophrenia and major depressive disorder. A majority of disease-affected brain regions act as relay nodes within neural networks, which are known to be impaired in neuropsychiatric diseases. One of these regions is the claustrum, which has the highest connectivity in the human brain by regional volume. Its possible involvement in disturbed connectivity is yet incompletely explored, however. The present study aimed at searching for possible structural deviations of the claustrum in neuropsychiatric disorders. We found bilaterally reduced claustral volumes both in schizophrenia and in major depressive disorder. These structural impairments may have different, disease-related consequences: In patients with schizophrenia, they may contribute to sensory processing impairments, and in patients with major depressive disorder to disturbances in salience.
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Affiliation(s)
- Hans-Gert Bernstein
- Department of Psychiatry, Otto-von-Guericke-University, Leipziger Str. 44, 39120, Magdeburg, Germany.
| | - Anna Ortmann
- Department of Psychiatry, Otto-von-Guericke-University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Henrik Dobrowolny
- Department of Psychiatry, Otto-von-Guericke-University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Johann Steiner
- Department of Psychiatry, Otto-von-Guericke-University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Ralf Brisch
- Institute of Forensic Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Tomasz Gos
- Institute of Forensic Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Bernhard Bogerts
- Department of Psychiatry, Otto-von-Guericke-University, Leipziger Str. 44, 39120, Magdeburg, Germany
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7
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Williams MR, Pattni S, Pearce RK, Hirsch SR, Maier M. Basolateral but not corticomedial amygdala shows neuroarchitectural changes in schizophrenia. J Neurosci Res 2016; 94:544-7. [PMID: 26752074 DOI: 10.1002/jnr.23683] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/26/2015] [Accepted: 10/07/2015] [Indexed: 11/05/2022]
Affiliation(s)
| | - Seema Pattni
- Mersey Deanery for General Practice, Health Education North West; Liverpool United Kingdom
| | | | | | - Michael Maier
- Trust HQ, West London Mental Health NHS Trust; Southall Middlesex United Kingdom
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8
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Bakhshi K, Chance S. The neuropathology of schizophrenia: A selective review of past studies and emerging themes in brain structure and cytoarchitecture. Neuroscience 2015; 303:82-102. [DOI: 10.1016/j.neuroscience.2015.06.028] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 01/12/2023]
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9
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Deletion of Rapgef6, a candidate schizophrenia susceptibility gene, disrupts amygdala function in mice. Transl Psychiatry 2015; 5:e577. [PMID: 26057047 PMCID: PMC4490285 DOI: 10.1038/tp.2015.75] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/22/2015] [Accepted: 04/23/2015] [Indexed: 02/01/2023] Open
Abstract
In human genetic studies of schizophrenia, we uncovered copy-number variants in RAPGEF6 and RAPGEF2 genes. To discern the effects of RAPGEF6 deletion in humans, we investigated the behavior and neural functions of a mouse lacking Rapgef6. Rapgef6 deletion resulted in impaired amygdala function measured as reduced fear conditioning and anxiolysis. Hippocampal-dependent spatial memory and prefrontal cortex-dependent working memory tasks were intact. Neural activation measured by cFOS phosphorylation demonstrated a reduction in hippocampal and amygdala activation after fear conditioning, while neural morphology assessment uncovered reduced spine density and primary dendrite number in pyramidal neurons of the CA3 hippocampal region of knockout mice. Electrophysiological analysis showed enhanced long-term potentiation at cortico-amygdala synapses. Rapgef6 deletion mice were most impaired in hippocampal and amygdalar function, brain regions implicated in schizophrenia pathophysiology. The results provide a deeper understanding of the role of the amygdala in schizophrenia and suggest that RAPGEF6 may be a novel therapeutic target in schizophrenia.
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10
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Differentiating between self and others: an ALE meta-analysis of fMRI studies of self-recognition and theory of mind. Brain Imaging Behav 2014; 8:24-38. [PMID: 24535033 DOI: 10.1007/s11682-013-9266-8] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The perception of self and others is a key aspect of social cognition. In order to investigate the neurobiological basis of this distinction we reviewed two classes of task that study self-awareness and awareness of others (theory of mind, ToM). A reliable task to measure self-awareness is the recognition of one's own face in contrast to the recognition of others' faces. False-belief tasks are widely used to identify neural correlates of ToM as a measure of awareness of others. We performed an activation likelihood estimation meta-analysis, using the fMRI literature on self-face recognition and false-belief tasks. The brain areas involved in performing false-belief tasks were the medial prefrontal cortex (MPFC), bilateral temporo-parietal junction, precuneus, and the bilateral middle temporal gyrus. Distinct self-face recognition regions were the right superior temporal gyrus, the right parahippocampal gyrus, the right inferior frontal gyrus/anterior cingulate cortex, and the left inferior parietal lobe. Overlapping brain areas were the superior temporal gyrus, and the more ventral parts of the MPFC. We confirmed that self-recognition in contrast to recognition of others' faces, and awareness of others involves a network that consists of separate, distinct neural pathways, but also includes overlapping regions of higher order prefrontal cortex where these processes may be combined. Insights derived from the neurobiology of disorders such as autism and schizophrenia are consistent with this notion.
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11
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Patrick RE, Rastogi A, Christensen BK. Effortful versus automatic emotional processing in schizophrenia: Insights from a face-vignette task. Cogn Emot 2014; 29:767-83. [DOI: 10.1080/02699931.2014.935297] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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12
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Crow TJ, Chance SA, Priddle TH, Radua J, James AC. Laterality interacts with sex across the schizophrenia/bipolarity continuum: an interpretation of meta-analyses of structural MRI. Psychiatry Res 2013; 210:1232-44. [PMID: 24011847 DOI: 10.1016/j.psychres.2013.07.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 06/29/2013] [Accepted: 07/31/2013] [Indexed: 12/30/2022]
Abstract
Review of the first comprehensive meta-analysis of VBM (voxel-based morphometry) studies in schizophrenia indicates asymmetrical reductions of anterior cingulate gyrus to the right, and medial temporal lobe (including the uncus) and para-hippocampal gyrus to the left. In subsequent meta-analyses of schizophrenia and bipolar disorder change in these limbic structures is systematically related to change in the insula. Deficits in insula (and para-hippocampal gyrus) to the left, and dorsal anterior cingulate gyrus to the right are greater in schizophrenic psychoses whereas deficits in anterior cingulate to the left and insula to the right are greater in bipolar illness. Thus (1) brain structures implicated in schizophrenia include those implicated in bipolar disorder, (2) the variation that separates the prototypical psychoses may be a subset of that relating to the structural asymmetry (the "torque") characteristic of the human brain, and (3) the meta-analysis of Bora et al. (2012) indicates that laterality of involvement of the insula and cingulate gyrus across the spectrum of bipolar and schizophrenic psychoses is critically dependent upon the sex ratio. Thus structural change underlying the continuum of psychosis relates to the interaction of laterality and sex.
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Affiliation(s)
- Timothy J Crow
- SANE POWIC, University Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX, UK.
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13
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Bansal R, Hao X, Liu F, Xu D, Liu J, Peterson BS. The effects of changing water content, relaxation times, and tissue contrast on tissue segmentation and measures of cortical anatomy in MR images. Magn Reson Imaging 2013; 31:1709-30. [PMID: 24055410 PMCID: PMC4241465 DOI: 10.1016/j.mri.2013.07.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/24/2013] [Accepted: 07/26/2013] [Indexed: 11/23/2022]
Abstract
Water content is the dominant chemical compound in the brain and it is the primary determinant of tissue contrast in magnetic resonance (MR) images. Water content varies greatly between individuals, and it changes dramatically over time from birth through senescence of the human life span. We hypothesize that the effects that individual- and age-related variations in water content have on contrast of the brain in MR images also have important, systematic effects on in vivo, MRI-based measures of regional brain volumes. We also hypothesize that changes in water content and tissue contrast across time may account for age-related changes in regional volumes, and that differences in water content or tissue contrast across differing neuropsychiatric diagnoses may account for differences in regional volumes across diagnostic groups. We demonstrate in several complementary ways that subtle variations in water content across age and tissue compartments alter tissue contrast, and that changing tissue contrast in turn alters measures of the thickness and volume of the cortical mantle: (1) We derive analytic relations describing how age-related changes in tissue relaxation times produce age-related changes in tissue gray-scale intensity values and tissue contrast; (2) We vary tissue contrast in computer-generated images to assess its effects on tissue segmentation and volumes of gray matter and white matter; and (3) We use real-world imaging data from adults with either Schizophrenia or Bipolar Disorder and age- and sex-matched healthy adults to assess the ways in which variations in tissue contrast across diagnoses affects group differences in tissue segmentation and associated volumes. We conclude that in vivo MRI-based morphological measures of the brain, including regional volumes and measures of cortical thickness, are a product of, or at least are confounded by, differences in tissue contrast across individuals, ages, and diagnostic groups, and that differences in tissue contrast in turn likely derive from corresponding differences in water content of the brain across individuals, ages, and diagnostic groups.
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Affiliation(s)
- Ravi Bansal
- Department of Psychiatry, Columbia College of Physicians and Surgeons and the New York State Psychiatric Institute, New York, NY 10032.
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14
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Zimmerman EC, Bellaire M, Ewing SG, Grace AA. Abnormal stress responsivity in a rodent developmental disruption model of schizophrenia. Neuropsychopharmacology 2013; 38:2131-9. [PMID: 23652286 PMCID: PMC3773662 DOI: 10.1038/npp.2013.110] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 05/01/2013] [Accepted: 05/03/2013] [Indexed: 12/22/2022]
Abstract
Although numerous studies have implicated stress in the pathophysiology of schizophrenia, less is known about how the effects of stress interact with genetic, developmental, and/or environmental determinants to promote disease progression. In particular, it has been proposed that in humans, stress exposure in adolescence could combine with a predisposition towards increased stress sensitivity, leading to prodromal symptoms and eventually psychosis. However, the neurobiological substrates for this interaction are not fully characterized. Previous work in our lab has demonstrated that rats born to dams administered with the DNA-methylating agent methylazoxymethanol acetate (MAM) at gestational day 17 exhibit as adults behavioral and anatomical abnormalities consistent with those observed in patients with schizophrenia. Here, we examined behavioral and neuroendocrine responses to stress in the MAM model of schizophrenia. MAM-treated male rats were exposed to acute and repeated footshock stress at prepubertal, peripubteral, and adult ages. Ultrasonic vocalizations (USVs), freezing, and corticosterone responses were quantified. We found that juvenile MAM-treated rats emitted significantly more calls, spent more time vocalizing, emitted calls at a higher rate, and showed more freezing in response to acute footshock stress when compared with their saline (SAL) treated counterparts, and that this difference is not present in older animals. In addition, adolescent MAM-treated animals displayed a blunted HPA axis corticosterone response to acute footshock that did not adapt after 10 days of stress exposure. These data demonstrate abnormal stress responsivity in the MAM model of schizophrenia and suggest that these animals are more sensitive to the effects of stress in youth.
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Affiliation(s)
- Eric C Zimmerman
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA,Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh School of Medicine, Medical Scientist Training Program, 526 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA, Tel: +1 262 893 8186, Fax: +1 412 624 9198, E-mail:
| | - Mark Bellaire
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Samuel G Ewing
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
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15
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Stjepanović D, Lorenzetti V, Yücel M, Hawi Z, Bellgrove MA. Human amygdala volume is predicted by common DNA variation in the stathmin and serotonin transporter genes. Transl Psychiatry 2013; 3:e283. [PMID: 23860484 PMCID: PMC3731781 DOI: 10.1038/tp.2013.41] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 12/16/2022] Open
Abstract
Despite the relevance of changes in amygdala volume to psychiatric illnesses and its heritability in both health and disease, the influence of common genetic variation on amygdala morphology remains largely unexplored. In the present study, we investigated the influence of a number of novel genetic variants on amygdala volume in 139 neurologically healthy individuals of European descent. Amygdala volume was significantly associated with allelic variation in the stathmin (STMN1) and serotonin transporter (SLC6A4) genes, which have been linked to healthy and disordered affective processing. These results were replicated across both manual and automated methods of amygdala parcellation, although manual tracing showed stronger effects, providing a cautionary note to studies relying on automated parcellation methods. Future studies will need to determine whether amygdala volume mediates the impact of stathmin and serotonin transporter gene variants on normal and dysfunctional emotion processing.
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Affiliation(s)
- D Stjepanović
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.
| | - V Lorenzetti
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne and Melbourne Health, Melbourne, Victoria, Australia,School of Psychology and Psychiatry, Monash University, Melbourne, Victoria, Australia
| | - M Yücel
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne and Melbourne Health, Melbourne, Victoria, Australia,School of Psychology and Psychiatry, Monash University, Melbourne, Victoria, Australia
| | - Z Hawi
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia,School of Psychology and Psychiatry, Monash University, Melbourne, Victoria, Australia
| | - M A Bellgrove
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia,School of Psychology and Psychiatry, Monash University, Melbourne, Victoria, Australia
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16
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Weisinger B, Greenstein D, Mattai A, Clasen L, Lalonde F, Feldman S, Miller R, Tossell JW, Vyas NS, Stidd R, David C, Gogtay N. Lack of gender influence on cortical and subcortical gray matter development in childhood-onset schizophrenia. Schizophr Bull 2013; 39:52-8. [PMID: 21613381 PMCID: PMC3523910 DOI: 10.1093/schbul/sbr049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Progressive cortical gray matter (GM) abnormalities are an established feature of schizophrenia and are more pronounced in rare, severe, and treatment refractory childhood-onset schizophrenia (COS) cases. The effect of sex on brain development in schizophrenia is poorly understood and studies to date have produced inconsistent results. METHODS Using the largest to date longitudinal sample of COS cases (n = 104, scans = 249, Male/Female [M/F] = 57/47), we compared COS sex differences with sex differences in a sample of matched typically developing children (n = 104, scans = 244, M/F = 57/47), to determine whether or not sex had differential effects on cortical and subcortical brain development in COS. RESULTS Our results showed no significant differential sex effects in COS for either GM cortical thickness or subcortical volume development (sex × diagnosis × age interaction; false discovery rate q = 0.05). CONCLUSION Sex appears to play a similar role in cortical and subcortical GM development in COS as it does in normally developing children.
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Affiliation(s)
- Brian Weisinger
- Child Psychiatry Branch, National Institutes of Mental Health, 10/3N202, 10 Center Drive, Bethesda, MD, USA.
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17
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Olabi B, Ellison-Wright I, Bullmore E, Lawrie SM. Structural brain changes in First Episode Schizophrenia compared with Fronto-Temporal Lobar Degeneration: a meta-analysis. BMC Psychiatry 2012; 12:104. [PMID: 22870896 PMCID: PMC3492014 DOI: 10.1186/1471-244x-12-104] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 07/31/2012] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The authors sought to compare gray matter changes in First Episode Schizophrenia (FES) compared with Fronto-Temporal Lobar Degeneration (FTLD) using meta-analytic methods applied to neuro-imaging studies. METHODS A systematic search was conducted for published, structural voxel-based morphometric MRI studies in patients with FES or FTLD. Data were combined using anatomical likelihood estimation (ALE) to determine the extent of gray matter decreases and analysed to ascertain the degree of overlap in the spatial distribution of brain changes in both diseases. RESULTS Data were extracted from 18 FES studies (including a total of 555 patients and 621 comparison subjects) and 20 studies of FTLD or related disorders (including a total of 311 patients and 431 comparison subjects). The similarity in spatial overlap of brain changes in the two disorders was significant (p = 0.001). Gray matter deficits common to both disorders included bilateral caudate, left insula and bilateral uncus regions. CONCLUSIONS There is a significant overlap in the distribution of structural brain changes in First Episode Schizophrenia and Fronto-Temporal Lobar Degeneration. This may reflect overlapping aetiologies, or a common vulnerability of these regions to the distinct aetio-pathological processes in the two disorders.
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Affiliation(s)
- Bayanne Olabi
- Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, EH10 5HF, UK.
| | | | - Ed Bullmore
- Department of Psychiatry, Behavioral & Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK,Cambridgeshire & Peterborough NHS Foundation Trust, Cambridge, UK
| | - Stephen M Lawrie
- Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, EH10 5HF, UK
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García-Amado M, Prensa L. Stereological analysis of neuron, glial and endothelial cell numbers in the human amygdaloid complex. PLoS One 2012; 7:e38692. [PMID: 22719923 PMCID: PMC3374818 DOI: 10.1371/journal.pone.0038692] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 05/09/2012] [Indexed: 02/02/2023] Open
Abstract
Cell number alterations in the amygdaloid complex (AC) might coincide with neurological and psychiatric pathologies with anxiety imbalances as well as with changes in brain functionality during aging. This stereological study focused on estimating, in samples from 7 control individuals aged 20 to 75 years old, the number and density of neurons, glia and endothelial cells in the entire AC and in its 5 nuclear groups (including the basolateral (BL), corticomedial and central groups), 5 nuclei and 13 nuclear subdivisions. The volume and total cell number in these territories were determined on Nissl-stained sections with the Cavalieri principle and the optical fractionator. The AC mean volume was 956 mm3 and mean cell numbers (x106) were: 15.3 neurons, 60 glial cells and 16.8 endothelial cells. The numbers of endothelial cells and neurons were similar in each AC region and were one fourth the number of glial cells. Analysis of the influence of the individuals’ age at death on volume, cell number and density in each of these 24 AC regions suggested that aging does not affect regional size or the amount of glial cells, but that neuron and endothelial cell numbers respectively tended to decrease and increase in territories such as AC or BL. These accurate stereological measures of volume and total cell numbers and densities in the AC of control individuals could serve as appropriate reference values to evaluate subtle alterations in this structure in pathological conditions.
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Affiliation(s)
- María García-Amado
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lucía Prensa
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- * E-mail:
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19
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Watson DR, Bai F, Barrett SL, Turkington A, Rushe TM, Mulholland CC, Cooper SJ. Structural changes in the hippocampus and amygdala at first episode of psychosis. Brain Imaging Behav 2012; 6:49-60. [PMID: 22045236 DOI: 10.1007/s11682-011-9141-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hippocampus and amygdala changes have been implicated in the pathophysiology and symptomatology of both schizophrenia (SCZ) and bipolar disorder (BD). However relationships between illness course, neuropathological changes and variations in symptomatology remain unclear. This investigation examined the associations between hippocampus and amygdala volumes and symptom dimensions in schizophrenia and bipolar disorder patients after their first episode of psychosis. Symptom severity was associated with decreases in hippocampus/amygdala complex volume across groups. In keeping with previous work bilateral hippocampus and amygdala volume reductions were also identified in the SCZ patients while in BD patients only evidence of amygdala inflation reached significance. The study concludes that there appear to be important relationships between volume changes in the hippocampus and amygdala and dimensions and severity of symptomatology in psychosis. Structural alterations are apparent in both SCZ and BD after first episode of psychosis but present differently in each illness and are more severe in SCZ.
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Affiliation(s)
- David R Watson
- Computational Neuroscience, ISRC, University of Ulster (Magee), Northland Road, Londonderry BT48 7JL, UK.
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Lepage M, Sergerie K, Benoit A, Czechowska Y, Dickie E, Armony JL. Emotional face processing and flat affect in schizophrenia: functional and structural neural correlates. Psychol Med 2011; 41:1833-1844. [PMID: 21284912 DOI: 10.1017/s0033291711000031] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND There is a general consensus in the literature that schizophrenia causes difficulties with facial emotion perception and discrimination. Functional brain imaging studies have observed reduced limbic activity during facial emotion perception but few studies have examined the relation to flat affect severity. METHOD A total of 26 people with schizophrenia and 26 healthy controls took part in this event-related functional magnetic resonance imaging study. Sad, happy and neutral faces were presented in a pseudo-random order and participants indicated the gender of the face presented. Manual segmentation of the amygdala was performed on a structural T1 image. RESULTS Both the schizophrenia group and the healthy control group rated the emotional valence of facial expressions similarly. Both groups exhibited increased brain activity during the perception of emotional faces relative to neutral ones in multiple brain regions, including multiple prefrontal regions bilaterally, the right amygdala, right cingulate cortex and cuneus. Group comparisons, however, revealed increased activity in the healthy group in the anterior cingulate, right parahippocampal gyrus and multiple visual areas. In schizophrenia, the severity of flat affect correlated significantly with neural activity in several brain areas including the amygdala and parahippocampal region bilaterally. CONCLUSIONS These results suggest that many of the brain regions involved in emotional face perception, including the amygdala, are equally recruited in both schizophrenia and controls, but flat affect can also moderate activity in some other brain regions, notably in the left amygdala and parahippocampal gyrus bilaterally. There were no significant group differences in the volume of the amygdala.
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Affiliation(s)
- M Lepage
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Verdun, Québec, Canada.
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21
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Saygin ZM, Osher DE, Augustinack J, Fischl B, Gabrieli JDE. Connectivity-based segmentation of human amygdala nuclei using probabilistic tractography. Neuroimage 2011; 56:1353-61. [PMID: 21396459 DOI: 10.1016/j.neuroimage.2011.03.006] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/25/2011] [Accepted: 03/02/2011] [Indexed: 11/30/2022] Open
Abstract
The amygdala plays an important role in emotional and social functions, and amygdala dysfunction has been associated with multiple neuropsychiatric disorders, including autism, anxiety, and depression. Although the amygdala is composed of multiple anatomically and functionally distinct nuclei, typical structural magnetic resonance imaging (MRI) sequences are unable to discern them. Thus, functional MRI (fMRI) studies typically average the BOLD response over the entire structure, which reveals some aspects of amygdala function as a whole but does not distinguish the separate roles of specific nuclei in humans. We developed a method to segment the human amygdala into its four major nuclei using only diffusion-weighted imaging and connectivity patterns derived mainly from animal studies. We refer to this new method as Tractography-based Segmentation, or TractSeg. The segmentations derived from TractSeg were topographically similar to their corresponding amygdaloid nuclei, and were validated against a high-resolution scan in which the nucleic boundaries were visible. In addition, nuclei topography was consistent across subjects. TractSeg relies on short scan acquisitions and widely accessible software packages, making it attractive for use in healthy populations to explore normal amygdala nucleus function, as well as in clinical and pediatric populations. Finally, it paves the way for implementing this method in other anatomical regions which are also composed of functional subunits that are difficult to distinguish with standard structural MRI.
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Affiliation(s)
- Zeynep M Saygin
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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22
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Tomasino B, Bellani M, Perlini C, Rambaldelli G, Cerini R, Isola M, Balestrieri M, Calì S, Versace A, Pozzi Mucelli R, Gasparini A, Tansella M, Brambilla P. Altered microstructure integrity of the amygdala in schizophrenia: a bimodal MRI and DWI study. Psychol Med 2011; 41:301-311. [PMID: 20459886 DOI: 10.1017/s0033291710000875] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The amygdala plays a central role in the fronto-limbic network involved in the processing of emotions. Structural and functional abnormalities of the amygdala have recently been found in schizophrenia, although there are still contradictory results about its reduced or preserved volumes. METHOD In order to address these contradictory findings and to further elucidate the possibly underlying pathophysiological process of the amygdala, we employed structural magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI), exploring amygdalar volume and microstructural changes in 69 patients with schizophrenia and 72 matched healthy subjects, relating these indices to psychopathological measures. RESULTS Measuring water diffusivity, the apparent diffusion coefficients (ADCs) for the right amygdala were found to be significantly greater in patients with schizophrenia compared with healthy controls, with a trend for abnormally reduced volumes. Also, significant correlations between mood symptoms and amygdalar volumes were found in schizophrenia. CONCLUSIONS We therefore provide evidence that schizophrenia is associated with disrupted tissue organization of the right amygdala, despite partially preserved size, which may ultimately lead to abnormal emotional processing in schizophrenia. This result confirms the major role of the amygdala in the pathophysiology of schizophrenia and is discussed with respect to amygdalar structural and functional abnormalities found in patients suffering from this illness.
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Affiliation(s)
- B Tomasino
- Scientific Institute IRCCS E. Medea, Udine, Italy
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Stereological approaches to identifying neuropathology in psychosis. Biol Psychiatry 2011; 69:113-26. [PMID: 20678756 PMCID: PMC2974031 DOI: 10.1016/j.biopsych.2010.04.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 04/28/2010] [Accepted: 04/30/2010] [Indexed: 12/12/2022]
Abstract
The challenges involved in identifying the neuropathological substrates of the clinical syndrome recognized as schizophrenia are well known. Stereological sampling provides a means to obtain accurate and precise quantitative estimates of components of neural circuits and thus offers promise of an enhanced capacity to detect subtle alterations in brain structure associated with schizophrenia. In this review, we 1) consider the importance and rationale for robust quantitative measures of brain abnormalities in postmortem studies of schizophrenia; 2) provide a brief overview of stereological methods for obtaining such measures; 3) discuss the methodological details that should be reported to document the robustness of a stereological study; 4) given the constraints of postmortem human studies, suggest how to approach the limitations of less robust designs; and 5) present an overview of methodologically sound stereological estimates from postmortem studies of schizophrenia.
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Schumann CM, Bauman MD, Amaral DG. Abnormal structure or function of the amygdala is a common component of neurodevelopmental disorders. Neuropsychologia 2010; 49:745-59. [PMID: 20950634 DOI: 10.1016/j.neuropsychologia.2010.09.028] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 08/25/2010] [Accepted: 09/22/2010] [Indexed: 12/22/2022]
Abstract
The amygdala, perhaps more than any other brain region, has been implicated in numerous neuropsychiatric and neurodevelopmental disorders. It is part of a system initially evolved to detect dangers in the environment and modulate subsequent responses, which can profoundly influence human behavior. If its threshold is set too low, normally benign aspects of the environment are perceived as dangers, interactions are limited, and anxiety may arise. If set too high, risk taking increases and inappropriate sociality may occur. Given that many neurodevelopmental disorders involve too little or too much anxiety or too little of too much social interaction, it is not surprising that the amygdala has been implicated in many of them. In this chapter, we begin by providing a brief overview of the phylogeny, ontogeny, and function of the amygdala and then appraise data from neurodevelopmental disorders which suggest amygdala dysregulation. We focus on neurodevelopmental disorders where there is evidence of amygdala dysregulation from postmortem studies, structural MRI analyses or functional MRI. However, the results are often disparate and it is not totally clear whether this is due to inherent heterogeneity or differences in methodology. Nonetheless, the amygdala is a common site for neuropathology in neurodevelopmental disorders and is therefore a potential target for therapeutics to alleviate associated symptoms.
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Affiliation(s)
- Cynthia M Schumann
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA 95618, USA.
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25
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Welch KA, Stanfield AC, Moorhead TW, Haga K, Owens DCG, Lawrie SM, Johnstone EC. Amygdala volume in a population with special educational needs at high risk of schizophrenia. Psychol Med 2010; 40:945-954. [PMID: 19732477 DOI: 10.1017/s0033291709990870] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The mildly learning disabled population has a three-fold elevated risk for schizophrenia. It has been proposed that in some individuals this cognitive limitation is a pre-psychotic manifestation of early onset schizophrenia. We examined clinical and neuroanatomical measures of a putative extended phenotype of schizophrenia in an adolescent population receiving special educational assistance. We predicted that people with intellectual impairment and schizotypal features would exhibit amygdala volume reduction as one of the neuroanatomical abnormalities associated with schizophrenia. METHOD Assessment by clinical interview, neuropsychological assessment and magnetic resonance imaging scanning was carried out in 28 intellectually impaired individuals identified as being at elevated risk of schizophrenia due to the presence of schizotypal traits, 39 intellectually impaired controls and 29 non-intellectually impaired controls. Amygdala volume was compared in these three groups and the relationship between symptomatology and amygdala volume investigated. RESULTS Right amygdala volume was significantly increased in the elevated risk group compared with the intellectually impaired controls (p=0.05). A significant negative correlation was seen between left amygdala volume and severity of negative symptoms within this group (p<0.05), but not in either control group. CONCLUSIONS Intellectually impaired subjects judged to be at elevated risk of schizophrenia on the basis of clinical assessment exhibit structural imaging findings which distinguish them from the generality of learning disabled subjects. Within this population reduced amygdala volume may be associated with negative-type symptoms and be part of an extended phenotype that reflects particularly elevated risk and/or early manifestations of the development of psychosis.
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Affiliation(s)
- K A Welch
- Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh EH10 5HF, UK.
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26
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Abstract
In the etymology of schizophrenia, the genetic component seems to play an essential role. Studies have shown more than 130 genes of susceptibility for schizophrenia: the majority of these studies, however, has yet to be confirmed- they are searching for more definition on the relevant functions of the genetic variation of schizophrenia. Recent studies suggest that a cluster of candidate genes in the interconnected network pathways are implicated in transmission of the glutamate the plasticity of the synapses, in oxidative stress, myelination and the profitability of oligodendrocytes. Previous neuropathological studies on schizophrenia did not identify specific neurodegenerative characteristics of this disease. Scientific evidence suggests that the physiopathology of schizophrenia involves alterations of the intracellular transmission pathway, those which are associated with reduced cerebral volume in some structures of white and gray matter. In particular, in schizophrenia, a reduction of medium cerebral volume has been observed, as has a reduction of the cortical regional volumes with reference to the frontal, temporal, and parietal areas of the brain - this is all in addition to a reduction of the prefrontal cortex, hippocampus, amygdala, thalamus, and the cerebellum. The cytoarchitectonic alterations in schizophrenia may be an expression of the pathology's processing, as are axonal damage and loss, reduction of myelination, and loss of neuropil. These all contribute to the reduction of the volume of the cerebral parenchima, and the corresponding augmentation of the cerebral spinal fluid. The inheritance of schizophrenia may appear high/elevated, but not a certain eventuality. In analysis of subtype specifics. However, this statistics remains significant in all studies. The role of the environmental factors in the development of schizophrenia is highlighted by studies which have been conducted on monozygotic patients affected by schizophrenia. While their genetic code is 100% similar, that is to say, entirely identical, one of the pair can be diagnosed as schizophrenic, while the other of the monozygotic pair has the 50% of the possibility not to contract schizophrenia. It is well known that genetic and environmental factors influence multiple aspects of human behavior, they can increase the susceptibility towards a mental disturbance. The reciprocal effects of these factors are placed in two distinct and diverse categories: gene environment interaction, which expresses the terminal genetic variations of susceptibility to environmental risk, and environmental gene correlations, where the genetic variability can increase or reduce the likelihood of the exposure to environmental determinant risk, includes early stressful events of life.
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Affiliation(s)
- C.M.V. Conti
- Department of Biomedical Science, Clinical Psychology Division, University of Chieti, Italy
| | - M. Fulcheri
- Department of Biomedical Science, Clinical Psychology Division, University of Chieti, Italy
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Brabec J, Rulseh A, Hoyt B, Vizek M, Horinek D, Hort J, Petrovicky P. Volumetry of the human amygdala - an anatomical study. Psychiatry Res 2010; 182:67-72. [PMID: 20227858 DOI: 10.1016/j.pscychresns.2009.11.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 10/13/2009] [Accepted: 11/11/2009] [Indexed: 11/17/2022]
Abstract
A striking feature of the studies that have addressed the measurement of the amygdala is the wide range of volumes encountered, with reports of volumes ranging from 1 to almost 4 cm(3). Another striking feature is the number of discrepancies in the landmarks adopted for manual tracing in magnetic resonance imaging (MRI). The goal of our study was to assess the anatomical volume of the amygdala on the basis of its cytoarchitecture while comparing the differences in age and sex. This study was performed on 21 normal male brains (mean age of 56.8 years) and 9 normal female brains (mean age of 61.2 years). The volume of the amygdala was measured by planimetry of Nissl-stained serial sections using ImageJ software. To address the complexity of the amygdala, we elected to use two types of amygdalar measurement that differ mainly in the definition of anterior pole boundaries. The average size of the classic amygdala was 1.24 cm(3) (S.D.=0.14), while the average size of the amygdala with wider borders was 1.63 cm(3) (S.D.=0.2). No interhemispheric or intersexual differences were observed for either type of amygdalar measurement. Neither sex revealed any statistically important relationship between volume of the amygdala and age. Our study was concerned exclusively with the anatomical volume of the amygdala rather than the MRI volume. Nevertheless, our results may have important implications for MRI studies because as of yet there is no gold standard for manual volumetry of the amygdala.
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Affiliation(s)
- Jiri Brabec
- Institute of Anatomy, First Faculty of Medicine, Charles University in Prague, Czech Republic.
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28
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Matricon J, Bellon A, Frieling H, Kebir O, Le Pen G, Beuvon F, Daumas-Duport C, Jay TM, Krebs MO. Neuropathological and Reelin deficiencies in the hippocampal formation of rats exposed to MAM; differences and similarities with schizophrenia. PLoS One 2010; 5:e10291. [PMID: 20421980 PMCID: PMC2858661 DOI: 10.1371/journal.pone.0010291] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 03/15/2010] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Adult rats exposed to methylazoxymethanol (MAM) at embryonic day 17 (E17) consistently display behavioral characteristics similar to that observed in patients with schizophrenia and replicate neuropathological findings from the prefrontal cortex of psychotic individuals. However, a systematic neuropathological analysis of the hippocampal formation and the thalamus in these rats is lacking. It is also unclear if reelin, a protein consistently associated with schizophrenia and potentially involved in the mechanism of action of MAM, participates in the neuropathological effects of this compound. Therefore, a thorough assessment including cytoarchitectural and neuromorphometric measurements of eleven brain regions was conducted. Numbers of reelin positive cells and reelin expression and methylation levels were also studied. PRINCIPAL FINDINGS Compared to untreated rats, MAM-exposed animals showed a reduction in the volume of entorhinal cortex, hippocampus and mediodorsal thalamus associated with decreased neuronal soma. The entorhinal cortex also showed laminar disorganization and neuronal clusters. Reelin methylation in the hippocampus was decreased whereas reelin positive neurons and reelin expression were unchanged. CONCLUSIONS Our results indicate that E17-MAM exposure reproduces findings from the hippocampal formation and the mediodorsal thalamus of patients with schizophrenia while providing little support for reelin's involvement. Moreover, these results strongly suggest MAM-treated animals have a diminished neuropil, which likely arises from abnormal neurite formation; this supports a recently proposed pathophysiological hypothesis for schizophrenia.
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Affiliation(s)
- Julien Matricon
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
| | - Alfredo Bellon
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
- * E-mail: (AB); (MOK)
| | - Helge Frieling
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Department of Psychiatry, Socialpsychiatry and Psychotherapy, Hannover Medical School, Hannover, Germany
| | - Oussama Kebir
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
| | - Gwenaëlle Le Pen
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
| | - Frédéric Beuvon
- Neuropathology unit, Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
- INSERM U894, Laboratoire de Plasticité gliale et tumeurs cérébrales, Centre de Psychiatrie et Neurosciences, Paris, France
| | - Catherine Daumas-Duport
- Neuropathology unit, Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
- INSERM U894, Laboratoire de Plasticité gliale et tumeurs cérébrales, Centre de Psychiatrie et Neurosciences, Paris, France
| | - Thérèse M. Jay
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
| | - Marie-Odile Krebs
- INSERM U894, Laboratoire de Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, Paris, France
- Université Paris Descartes, Faculté de Médecine Paris Descartes, Hôpital Sainte-Anne, Paris, France
- * E-mail: (AB); (MOK)
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Berretta S, Pantazopoulos H, Lange N. Neuron numbers and volume of the amygdala in subjects diagnosed with bipolar disorder or schizophrenia. Biol Psychiatry 2007; 62:884-93. [PMID: 17698040 DOI: 10.1016/j.biopsych.2007.04.023] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2006] [Revised: 03/08/2007] [Accepted: 04/03/2007] [Indexed: 01/24/2023]
Abstract
BACKGROUND Growing evidence supports a pivotal role for the amygdala in the pathogenesis of bipolar disorder (BD) and schizophrenia (SZ). However, the occurrence of morphologic changes in the amygdala is currently controversial. METHODS Total number and numeric density of neurons, neuronal somata size, and volume of the lateral (LN), basal (BN), accessory basal (ABN), and cortical (CO) nuclei of the amygdala were measured in 12 normal control, 10 BD, and 16 SZ subjects. RESULTS In BD subjects, reductions of total numbers (41.1%; p = .01) and numeric densities of neurons (14.5%, p = .01), as well as volume (29.0%; p = .01), were detected in LN. Density of neurons was also decreased in ABN of the same subjects (20.8%; p = .0005). These changes were not related to antipsychotics or lithium salt exposure. In SZ subjects, a decrease of total numbers of neurons was detected in LN (23.6%; p = .04). This effect was no longer significant once exposure to antipsychotics was taken into account. CONCLUSIONS These findings offer structural evidence for an involvement of the amygdala in BD. Consequent loss of amygdalar function may account for abnormalities in emotion processing typical of BD subjects. In contrast, changes in SZ were limited and may have been induced by pharmacologic treatment.
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Affiliation(s)
- Sabina Berretta
- Translational Neuroscience Laboratory, McLean Hospital, Belmont, Massachusetts 02478, USA.
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Malykhin NV, Bouchard TP, Ogilvie CJ, Coupland NJ, Seres P, Camicioli R. Three-dimensional volumetric analysis and reconstruction of amygdala and hippocampal head, body and tail. Psychiatry Res 2007; 155:155-65. [PMID: 17493789 DOI: 10.1016/j.pscychresns.2006.11.011] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 09/14/2006] [Accepted: 11/26/2006] [Indexed: 11/28/2022]
Abstract
Volumetric changes in the amygdala and hippocampus are relevant to many disorders, but their close proximity makes it difficult to separate these structures by magnetic resonance imaging, leading many volumetric protocols to exclude problematic slices from analysis, or to analyze the amygdalo-hippocampal complex conjointly. The hippocampus tail is also often excluded, because of the difficulty in separating it from the thalamus. We have developed a reliable protocol for volumetric analysis and 3-D reconstruction of the amygdala and hippocampus (as a whole and in its anatomical parts). Twenty volunteers from clinical and healthy populations were recruited. T1-weighted images were acquired at 1.5 Tesla with native spatial resolution of 1.5 mm x 1.0 mm x 1.0 mm. Volumetric analyses were performed blind to diagnosis, using the interactive software package DISPLAY. Inter-rater (intrarater) intraclass correlations for the method were: 0.95 (0.88) for hippocampus tail, 0.83 (0.93) for hippocampus body, 0.95 (0.92) for hippocampus head, 0.96 (0.86) for total hippocampus and 0.86 (0.94) for amygdala. Volumes (mean+/-S.D.) corrected for intracranial volume for this mixed group were for the hippocampal tail: 0.325+/-0.087 cm(3); hippocampal body: 0.662+/-0.120 cm(3); hippocampal head: 1.23+/-0.174 cm(3); total hippocampus: 2.218+/-0.217 cm(3), and amygdala: 0.808+/-0.185 cm(3). In conclusion, the study demonstrates that the amygdala and hippocampal parts can be quantified reliably.
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Affiliation(s)
- Nikolai V Malykhin
- Department of Psychiatry, University of Alberta, Walter MacKenzie Centre, 8440-112 Street, Edmonton, Alberta, Canada
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31
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Sachdev PS, Chen X, Joscelyne A, Wen W, Brodaty H. Amygdala in stroke/transient ischemic attack patients and its relationship to cognitive impairment and psychopathology: the Sydney Stroke Study. Am J Geriatr Psychiatry 2007; 15:487-96. [PMID: 17545449 DOI: 10.1097/jgp.0b013e3180581fe6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To examine the structural abnormalities in the amygdala in stroke patients and see what contribution the amygdala may make to psychopathology and cognitive dysfunction related to stroke, because the amygdala has important roles in the processing of emotions, cognitive function, and psychiatric disorders. METHODS The authors assessed 47 stroke/transient ischemic attack (TIA) patients 3-6 months after the event and 54 comparison healthy subjects, using neuropsychological tests, medical and psychiatric examination and magnetic resonance imaging (MRI) brain scans. Volumetric T1-weighted MRI was used to obtain amygdala volumes by manual tracing. RESULTS Stroke/TIA patients had smaller right amygdalar volume, more white matter hyperintensities (WMHs), and larger lateral ventricles. The amygdala was smaller in stroke/TIA patients with cognitive impairment compared to those without impairment. The right amygdala volume was negatively correlated with visual new learning and not related to depression, anxiety, irritability, agitation or apathy at baseline or 12-month follow-up. However, baseline amygdala volume was negatively correlated with Hamilton depression scores at 12 months in healthy comparison subjects. Hypertension and atrial fibrillation, and to a lesser extent WMHs, were predictors of amygdala volume. CONCLUSION The amygdala is smaller in stroke/TIA patients, especially in those with cognitive impairment. This may partly be accounted for by hypertension, white matter lesions, and atrial fibrillation. It is not related to psychopathology except that small amygdalae may increase vulnerability to depression.
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Affiliation(s)
- Perminder S Sachdev
- School of Psychiatry, University of New South Wales, Academic Department for Old Age Psychiatry the Prince of Wales Hospital, Randwick, NSW, Australia.
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McHugh TL, Saykin AJ, Wishart HA, Flashman LA, Cleavinger HB, Rabin LA, Mamourian AC, Shen L. Hippocampal volume and shape analysis in an older adult population. Clin Neuropsychol 2007; 21:130-45. [PMID: 17366281 PMCID: PMC3482482 DOI: 10.1080/13854040601064534] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This report presents a manual segmentation protocol for the hippocampus that yields a reliable and comprehensive measure of volume, a goal that has proven difficult with prior methods. Key features of this method include alignment of the images in the long axis of the hippocampus and the use of a three-dimensional image visualization function to disambiguate anterior and posterior hippocampal boundaries. We describe procedures for hippocampal volumetry and shape analysis, provide inter- and intra-rater reliability data, and examine correlates of hippocampal volume in a sample of healthy older adults. Participants were 40 healthy older adults with no significant cognitive complaints, no evidence of mild cognitive impairment or dementia, and no other neurological or psychiatric disorder. Using a 1.5 T GE Signa scanner, three-dimensional spoiled gradient recalled acquisition in a steady state (SPGR) sequences were acquired for each participant. Images were resampled into 1 mm isotropic voxels, and realigned along the interhemispheric fissure in the axial and coronal planes, and the long axis of the hippocampus in the sagittal plane. Using the BRAINS program (Andreasen et al., 1993), the boundaries of the hippocampus were visualized in the three orthogonal views, and boundary demarcations were transferred to the coronal plane for tracing. Hippocampal volumes were calculated after adjusting for intracranial volume (ICV). Intra- and inter-rater reliabilities, measured using the intraclass correlation coefficient, exceeded .94 for both the left and right hippocampus. Total ICV-adjusted volumes were 3.48 (+/-0.43) cc for the left hippocampus and 3.68 (+/-0.42) for the right. There were no significant hippocampal volume differences between males and females (p > .05). In addition to providing a comprehensive volumetric measurement of the hippocampus, the refinements included in our tracing protocol permit analysis of changes in hippocampal shape. Shape analyses may yield novel information about structural brain changes in aging and dementia that are not reflected in volumetric measurements alone. These and other novel directions in research on hippocampal function and dysfunction will be facilitated by the use of reliable, comprehensive, and consistent segmentation and measurement methods.
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Affiliation(s)
- Tara L. McHugh
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Andrew J. Saykin
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
- Department of Radiology, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
- Department of Computer Science, Dartmouth College, Hanover, NH
| | - Heather A. Wishart
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Laura A. Flashman
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Howard B. Cleavinger
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Laura A. Rabin
- Department of Psychiatry, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Alexander C. Mamourian
- Department of Radiology, Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH
| | - Li Shen
- Department of Computer and Information Science, University of Massachusetts Dartmouth, MA, USA
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Kreczmanski P, Heinsen H, Mantua V, Woltersdorf F, Masson T, Ulfig N, Schmidt-Kastner R, Korr H, Steinbusch HWM, Hof PR, Schmitz C. Volume, neuron density and total neuron number in five subcortical regions in schizophrenia. ACTA ACUST UNITED AC 2007; 130:678-92. [PMID: 17303593 DOI: 10.1093/brain/awl386] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Several studies have pointed to alterations in mean volumes, neuron densities and total neuron numbers in the caudate nucleus (CN), putamen, nucleus accumbens (NA), mediodorsal nucleus of the thalamus (MDNT) and lateral nucleus of the amygdala (LNA) in schizophrenia. However, the results of these studies are conflicting and no clear pattern of alterations has yet been established in these subcortical regions, possibly due to differences in quantitative histological methods used as well as differences in the investigated case series. The present study investigates these subcortical regions in both hemispheres of the same post-mortem brains for volume, neuron density and total neuron number with high-precision design-based stereology. The analysed case series consisted of 13 post-mortem brains from male schizophrenic patients [age range: 22-64 years; mean age 51.5 +/- 3.3 years (mean +/- SEM)] and 13 age-matched male controls (age range: 25-65 years; mean age 51.9 +/- 3.1 years). A general linear model multivariate analysis of variance with diagnosis and hemisphere as fixed factors and illness duration (schizophrenic patients) or age (controls), post-mortem interval and fixation time as covariates showed a number of statistically significant alterations in the brains from schizophrenic patients compared with the controls. There was a reduced mean volume of the putamen [-5.0% on the left side (l) and -4.1% on the right side (r)] and the LNA (l: -12.1%, r: -17.6%), and a reduced mean total neuron number in the CN (l: -10.4%, r: -10.2%), putamen (l: -8.1%, r: -11.6%) and the LNA (l: -15.9%, r: -16.2%). These data show a previously unreported, distinct pattern of alterations in mean total neuron numbers in identified subcortical brain regions in a carefully selected sample of brains from schizophrenic patients. The rigorous quantitative analysis of several regions in brains from schizophrenic patients and matched controls is crucial to provide reliable information on the neuropathology of schizophrenia as well as insights about its pathogenesis.
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Affiliation(s)
- Pawel Kreczmanski
- Department of Psychiatry and Neuropsychology, Division of Cellular Neuroscience, Maastricht University, Maastricht, The Netherlands
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Job DE, Whalley HC, Johnstone EC, Lawrie SM. Grey matter changes over time in high risk subjects developing schizophrenia. Neuroimage 2005; 25:1023-30. [PMID: 15850721 DOI: 10.1016/j.neuroimage.2005.01.006] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 12/21/2004] [Accepted: 01/06/2005] [Indexed: 10/25/2022] Open
Abstract
Schizophrenia affects approximately 1% of the population and is associated with reductions in brain volume, but when these are first evident is unknown. Magnetic resonance imaging (MRI) has demonstrated abnormalities of brain structure, particularly of the temporal lobes, in schizophrenia. A study of brain structure in individuals destined to develop schizophrenia, before they do so, is crucial to understanding the illness. We used Voxel Based Morphometry (VBM) to map changes in Grey Matter Density (GMD) in 65 young adults at high risk of schizophrenia, for familial reasons, and 19 healthy young adults, over a period of approximately 2 years. All subjects were anti-psychotic naive at both scans. No increases in GMD were found in any of the groups. Within the high-risk group significant declines in GMD were found in the temporal lobes, the right frontal lobe and right parietal lobe. In the control group a decline was found in the right gyrus rectus. No significant differences over time were found between any of the groups. Those individuals at high risk who had transient or isolated psychotic symptoms showed a different spatial pattern of reductions in GMD than those who did not in within group comparisons. In addition, those individuals at high risk who later developed schizophrenia also showed a different spatial pattern of reductions in GMD in the left temporal lobe and right cerebellum, from 2 to 3 years before they were diagnosed. These particular reductions may therefore be able to predict the later onset of schizophrenia.
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Affiliation(s)
- Dominic E Job
- Division of Psychiatry, University of Edinburgh, The Royal Edinburgh Hospital, Morningside Park, Edinburgh EH10 5HF, Scotland, UK.
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35
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Tanskanen P, Veijola JM, Piippo UK, Haapea M, Miettunen JA, Pyhtinen J, Bullmore ET, Jones PB, Isohanni MK. Hippocampus and amygdala volumes in schizophrenia and other psychoses in the Northern Finland 1966 birth cohort. Schizophr Res 2005; 75:283-94. [PMID: 15885519 DOI: 10.1016/j.schres.2004.09.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 09/13/2004] [Accepted: 09/20/2004] [Indexed: 11/19/2022]
Abstract
Structural brain differences have been reported in many studies with schizophrenia, but few have involved a general population birth cohort. We investigated differences in volume, shape and laterality of hippocampus and amygdala in patients with schizophrenia, all psychoses and comparison subjects within a large general birth cohort sample, and explored effects of family history of psychosis, perinatal risk and age-at-onset of illness. All subjects with psychosis from the Northern Finland 1966 birth cohort were invited to a survey including MRI scan of the brain, conducted in 1999-2001. Comparison subjects not known to have psychosis were randomly selected from the same cohort. Volumes of hippocampus and amygdala were measured in 56 subjects with DSM-III-R schizophrenia, 26 patients with other psychoses and 104 comparison subjects. Small hippocampal volume reductions in schizophrenia (2%) and all psychoses (3%) were not significant when adjusted for total brain volume. The shape of hippocampus in schizophrenia did not differ significantly from comparison subjects. Right hippocampus and amygdala were significantly larger than the left in all groups. Mean amygdala volume in schizophrenia or all psychoses did not differ from comparison subjects. Patients with family history of psychosis had larger hippocampus than patients without. Neither perinatal risk nor age-at-onset of illness had any effect on hippocampal or amygdala volumes. Small hippocampal volume reduction in schizophrenia and all psychoses was not disproportionate to reduced whole brain volume in this population-based sample. Perinatal events that have been suggested as of etiological importance in structural pathology of psychosis had no effect.
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Affiliation(s)
- Päivikki Tanskanen
- University of Oulu, Department of Radiology, P.O. Box 50, FIN-90029 Oys, Finland.
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36
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Abstract
Neuroimaging probes of brain regions implicated in emotion represent an important research strategy for understanding emotional dysfunction in schizophrenia. Anterior limbic structures, such as the ventral striatum and the amygdala, have been implicated in the pathophysiology of schizophrenia and the generation of emotional responses, although few studies to date have used emotion probes to target these areas in schizophrenia. With this goal in mind, emotionally salient visual images were used in a simple, nondemanding task. In all, 13 medicated, schizophrenic patients, five unmedicated patients, and 10 healthy volunteers viewed complex visual pictures and a nonsalient, blank screen while regional cerebral blood flow was measured with the [O-15] water technique. Pictures consisted of real world scenes with aversive, positive, and nonaversive content. Eye movements were recorded simultaneous with scan acquisition. Positron emission tomography images were analyzed for baseline, tonic activity, in addition to phasic changes ('activation') to salient stimuli. Lateral eye movement measures and on-line ratings showed good behavioral compliance with the task. Patients with schizophrenia showed impaired neural responses to salient stimuli in the right ventral striatum (VS), and they exhibited elevated tonic activity levels in the right VS and bilateral amygdala, inversely correlated with overall symptom severity. The patients also showed reduced modulation of visual cortex by salient stimuli. The results show that patients with schizophrenia exhibit impaired neural responses to emotionally salient stimuli in the VS, supporting a role for this structure in the pathophysiology of the illness. Reduced modulation of visual cortex by emotionally salient stimuli also suggests a failure to organize cerebral activity at a global level.
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Affiliation(s)
- Stephan F Taylor
- Department of Psychiatry, University of Michigan, Ann Arbor, MI 48109, USA.
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Kalus P, Slotboom J, Gallinat J, Wiest R, Ozdoba C, Federspiel A, Strik WK, Buri C, Schroth G, Kiefer C. The amygdala in schizophrenia: a trimodal magnetic resonance imaging study. Neurosci Lett 2005; 375:151-6. [PMID: 15694250 DOI: 10.1016/j.neulet.2004.11.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2004] [Revised: 10/31/2004] [Accepted: 11/02/2004] [Indexed: 11/29/2022]
Abstract
In schizophrenic psychoses, structural and functional alterations of the amygdala have been demonstrated by several neuroimaging studies. However, postmortem examinations on the brains of schizophrenics did not confirm the volume changes reported by volumetric magnetic resonance imaging (MRI) studies. In order to address these contradictory findings and to further elucidate the possibly underlying pathophysiological process of the amygdala, we employed a trimodal MRI design including high-resolution volumetry, diffusion tensor imaging (DTI), and quantitative magnetization transfer imaging (qMTI) in a sample of 14 schizophrenic patients and 14 matched controls. Three-dimensional MRI volumetry revealed a significant reduction of amygdala raw volumes in the patient group, while amygdala volumes normalized for intracranial volume did not differ between the two groups. The regional diffusional anisotropy of the amygdala, expressed as inter-voxel coherence (COH), showed a marked and significant reduction in schizophrenics. Assessment of qMTI parameters yielded significant group differences for the T2 time of the bound proton pool and the T1 time of the free proton pool, while the semi-quantitative magnetization transfer ratio (MTR) did not differ between the groups. The application of multimodal MRI protocols is diagnostically relevant for the differentiation between schizophrenic patients and controls and provides a new strategy for the detection and characterization of subtle structural alterations in defined regions of the living brain.
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Affiliation(s)
- Peter Kalus
- Clinic for Psychiatry and Psychotherapy, Charité University Medicine, Campus Mitte, Psychiatrische Universitätsklinik der Charité im St. Hedwig-Krankenhaus, Turmstrasse 21, D-10559, Berlin, Germany.
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Murray RM, Sham P, Van Os J, Zanelli J, Cannon M, McDonald C. A developmental model for similarities and dissimilarities between schizophrenia and bipolar disorder. Schizophr Res 2004; 71:405-16. [PMID: 15474912 DOI: 10.1016/j.schres.2004.03.002] [Citation(s) in RCA: 347] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Revised: 03/08/2004] [Accepted: 03/10/2004] [Indexed: 02/04/2023]
Abstract
Schizophrenia and mania have a number of symptoms and epidemiological characteristics in common, and both respond to dopamine blockade. Family, twin and molecular genetic studies suggest that the reason for these similarities may be that the two conditions share certain susceptibility genes. On the other hand, individuals with schizophrenia have more obvious brain structural and neuropsychological abnormalities than those with bipolar disorder; and pre-schizophrenic children are characterised by cognitive and neuromotor impairments, which are not shared by children who later develop bipolar disorder. Furthermore, the risk-increasing effect of obstetric complications has been demonstrated for schizophrenia but not for bipolar disorder. Perinatal complications such as hypoxia are known to result in smaller volume of the amygdala and hippocampus, which have been frequently reported to be reduced in schizophrenia; familial predisposition to schizophrenia is also associated with decreased volume of these structures. We suggest a model to explain the similarities and differences between the disorders and propose that, on a background of shared genetic predisposition to psychosis, schizophrenia, but not bipolar disorder, is subject to additional genes or early insults, which impair neurodevelopment, especially of the medial temporal lobe.
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Affiliation(s)
- Robin M Murray
- Institute of Psychiatry, Psychological Medicine, Denmark Hill, DeCrespigny Park, London SE5 8AF, UK.
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39
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Niu L, Matsui M, Zhou SY, Hagino H, Takahashi T, Yoneyama E, Kawasaki Y, Suzuki M, Seto H, Ono T, Kurachi M. Volume reduction of the amygdala in patients with schizophrenia: a magnetic resonance imaging study. Psychiatry Res 2004; 132:41-51. [PMID: 15546702 DOI: 10.1016/j.pscychresns.2004.06.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Revised: 05/24/2004] [Accepted: 06/10/2004] [Indexed: 11/23/2022]
Abstract
The amygdala is known to be involved in the pathology of schizophrenia. While only a limited number of studies in schizophrenia have measured the amygdala as a single structure. The aim of this study was to examine the hypothesis that patients with schizophrenia would show reduced volumes in the amygdala compared with normal controls. We investigated amygdala volume in 40 patients with schizophrenia (20 males, 20 females) and 40 age- and gender-matched normal controls using three-dimensional magnetic resonance imaging (MRI). Whole volumes of both the amygdala and the temporal lobe were measured on consecutive coronal 1-mm slices. The amygdala volume was significantly smaller in schizophrenia patients than in controls. Considering gender differences, male patients had significantly smaller volumes in the bilateral amygdala than male controls; female patients had a significantly reduced right amygdala compared with female controls. Furthermore, a significant left-smaller-than-right volumetric asymmetry of the amygdala was detected in male patients with schizophrenia. The results may be important for understanding the role of the amygdala in the pathophysiology of schizophrenia and the anatomical substrates of gender difference in the expressions of the illness.
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Affiliation(s)
- Lisha Niu
- Department of Psychology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
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Kröner S, Rosenkranz JA, Grace AA, Barrionuevo G. Dopamine modulates excitability of basolateral amygdala neurons in vitro. J Neurophysiol 2004; 93:1598-610. [PMID: 15537813 DOI: 10.1152/jn.00843.2004] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The amygdala plays a role in affective behaviors, which are modulated by the dopamine (DA) innervation of the basolateral amygdala complex (BLA). Although in vivo studies indicate that activation of DA receptors alters BLA neuronal activity, it is unclear whether DA exerts direct effects on BLA neurons or whether it acts via indirect effects on BLA afferents. Using whole cell patch-clamp recordings in rat brain slices, we investigated the site and mechanisms through which DA regulates the excitability of BLA neurons. Dopamine enhanced the excitability of BLA projection neurons in response to somatic current injections via a postsynaptic effect. Dopamine D1 receptor activation increased excitability and evoked firing, whereas D2 receptor activation increased input resistance. Current- and voltage-clamp experiments in projection neurons showed that D1 receptor activation enhanced excitability by modulating a 4-aminopyridine- and alpha-dendrotoxin-sensitive, slowly inactivating K+ current. Furthermore, DA and D1 receptor activation increased evoked firing in fast-spiking BLA interneurons. Consistent with a postsynaptic modulation of interneuron excitability, DA also increased the frequency of spontaneous inhibitory postsynaptic currents recorded in projection neurons without changing release of GABA. These data demonstrate that DA exerts direct effects on BLA projection neurons and indirect actions via modulation of interneurons that may work in concert to enhance the neuronal response to large, suprathreshold inputs, while suppressing weaker inputs.
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Affiliation(s)
- Sven Kröner
- Center for Neural Basics Cognition, Deptartment of Neuroscience, University of Pittsburgh, Pittsburgh, Penssylvania.
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41
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The prefrontal cortex regulates lateral amygdala neuronal plasticity and responses to previously conditioned stimuli. J Neurosci 2003. [PMID: 14657162 DOI: 10.1523/jneurosci.23-35-11054.2003] [Citation(s) in RCA: 231] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The amygdala plays a role in learning and memory processes that involve an emotional component. However, neural structures that regulate these amygdala-dependent processes are unknown. Previous studies indicate that regulation of affect may be imposed by the prefrontal cortex (PFC) and its efferents to the amygdala. The presentation of conditioned affective stimuli enhances activity of neurons in the lateral nucleus of the amygdala (LAT), which is thought to drive conditioned affective responses. Moreover, plasticity of LAT neuronal responses to stimuli during the course of conditioning is believed to underlie affective learning. This study examines the role of the PFC in the regulation of affective behaviors by evaluating how the PFC affects LAT neuronal plasticity and activity that is evoked by previously conditioned stimuli. In vivo intracellular recordings were performed from the LAT of anesthetized rats during pavlovian conditioning and during the presentation of stimuli that were conditioned in the awake rat before recording. Train stimulation of the PFC suppressed LAT neuronal activity that was evoked by both previously conditioned and neutral stimuli. In addition, PFC stimulation blocked LAT neuronal plasticity associated with an affective conditioning procedure. These results indicate that the PFC has the potential to regulate affective processes by inhibition of the LAT. Patients with disruptions of the PFC-LAT interaction often display an inability to regulate affective responses. This may be attributable to the loss of PFC-imposed inhibition of the emotional response to a stimulus but may also include the formation or diminished extinction of inappropriate associations.
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Job DE, Whalley HC, McConnell S, Glabus M, Johnstone EC, Lawrie SM. Voxel-based morphometry of grey matter densities in subjects at high risk of schizophrenia. Schizophr Res 2003; 64:1-13. [PMID: 14511796 DOI: 10.1016/s0920-9964(03)00158-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The grey matter (GM) segments from T1 structural magnetic resonance (MR) images of the brain in subjects at high risk of schizophrenia (n=146) were compared with normal control subjects (n=36) and first episode schizophrenic subjects (n=34) using automated voxel-based morphometry (VBM). The subjects were recruited for the Edinburgh High Risk Study (EHRS) and regional brain volumes had previously been measured using a semi-automated volumetric region of interest (ROI) method of analysis. For the current report, the images were processed using a study specific template and statistically analysed using the SPM99 program. The small volume correction tool in SPM was also used to restrict the analyses to specific voxels. Reductions in the probability of grey matter (GM) density were seen bilaterally in the anterior cingulate, and as a trend in the left parahippocampal gyrus for the high-risk vs. control subjects. In contrast, first episode schizophrenia subjects had less GM than high-risk subjects in several frontal and temporal regions. These results are compatible with the findings of our previous volumetric ROI analysis.
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Affiliation(s)
- Dominic E Job
- Department of Psychiatry, University of Edinburgh, Kennedy Tower, Royal Edinburgh Hospital, Morningside Park, Edinburgh EH10 5HF, Scotland, UK.
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Phillips ML, Drevets WC, Rauch SL, Lane R. Neurobiology of emotion perception II: Implications for major psychiatric disorders. Biol Psychiatry 2003; 54:515-28. [PMID: 12946880 DOI: 10.1016/s0006-3223(03)00171-9] [Citation(s) in RCA: 1221] [Impact Index Per Article: 58.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
To date, there has been little investigation of the neurobiological basis of emotion processing abnormalities in psychiatric populations. We have previously discussed two neural systems: 1) a ventral system, including the amygdala, insula, ventral striatum, ventral anterior cingulate gyrus, and prefrontal cortex, for identification of the emotional significance of a stimulus, production of affective states, and automatic regulation of emotional responses; and 2) a dorsal system, including the hippocampus, dorsal anterior cingulate gyrus, and prefrontal cortex, for the effortful regulation of affective states and subsequent behavior. In this critical review, we have examined evidence from studies employing a variety of techniques for distinct patterns of structural and functional abnormalities in these neural systems in schizophrenia, bipolar disorder, and major depressive disorder. In each psychiatric disorder, the pattern of abnormalities may be associated with specific symptoms, including emotional flattening, anhedonia, and persecutory delusions in schizophrenia, prominent mood swings, emotional lability, and distractibility in bipolar disorder during depression and mania, and with depressed mood and anhedonia in major depressive disorder. We suggest that distinct patterns of structural and functional abnormalities in neural systems important for emotion processing are associated with specific symptoms of schizophrenia and bipolar and major depressive disorder.
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Affiliation(s)
- Mary L Phillips
- Division of Psychological Medicine, Institute of Psychiatry, London, United Kingdom
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Abstract
BACKGROUND The anatomical origin of the enlargement of the cerebral ventricles in schizophrenia is obscure. METHODS In this study, the volumes of the hemispheres and lateral ventricles were assessed in MRI scans of 43 formalin-fixed brains (23 from patients and 19 comparison subjects) using a spline 'snake' segmentation method. RESULTS A bilateral ventricular volume increase was found in schizophrenia. Whereas enlargement of the lateral ventricle (mean: 54%) as a whole was related to age of onset and was greater in females than in males, enlargement of the temporal horn (mean: 54%) was not strongly related to age of onset or sex. Lateral ventricle volume was negatively correlated with STG, fusiform and parahippocampal volume in schizophrenia. Hemispheric volumes were unchanged. CONCLUSIONS The differing correlates of the components of ventricular enlargement suggest a degree of selectivity of the disease process with a focus in the temporal lobe.
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45
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Andorn AC, Bennett TL, Gallagher KK, Hogan D. Antipsychotic drug interactions with specific [3H]ketanserin binding sites in membrane fragments derived from human prefrontal cortex and human amygdala. Brain Res 2003; 971:66-72. [PMID: 12691838 DOI: 10.1016/s0006-8993(03)02356-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two regions of the brain potentially significant for psychopathology in schizophrenia are the prefrontal cortex and the amygdala. Antipsychotic compounds bind at serotonin receptors in human prefrontal cortex. We hypothesized that the serotoninergic antagonist [3H]ketanserin would label similar sets of binding sites in these two brain regions. Further, we hypothesized that all antipsychotic compounds would show appreciable affinity for binding sites labeled by [3H]ketanserin in the prefrontal cortex. Our findings indicate some differences in [3H]ketanserin binding between prefrontal cortex and amygdala. We also observed that several antipsychotic compounds had very high affinity for the [3H]ketanserin binding sites in prefrontal cortex.
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Affiliation(s)
- Anne C Andorn
- Department of Psychiatry and Behavioral Sciences, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0431, USA.
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Fallon JH, Opole IO, Potkin SG. The neuroanatomy of schizophrenia: circuitry and neurotransmitter systems. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1566-2772(03)00022-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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47
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48
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Brierley B, Shaw P, David AS. The human amygdala: a systematic review and meta-analysis of volumetric magnetic resonance imaging. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2002; 39:84-105. [PMID: 12086710 DOI: 10.1016/s0165-0173(02)00160-1] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The structure and function of the human amygdala is attracting increasing attention in the scientific literature, particularly since the advent of high resolution magnetic resonance imaging (MRI). We carried out a systematic review of the published literature reporting left and right amygdala volumes from MRI in non-clinical subjects. Our aim was to estimate the normal range of the volume of the amygdala and to account for heterogeneity of the measures. The factors we considered included the detail given regarding various subject factors, the plane of scan acquisition, slice thickness and contiguity, magnet strength, positional and volume correction, and the reliability of measurement. Thirty-nine studies with 51 data sets fulfilled selection criteria. The mean+/-95% confidence interval for the left amygdala volume was 1726.7 mm(3)+/-35.1, and right was 1691.7 mm(3)+/-37.2. The left-right difference did not reach statistical significance. The overall range of reported volumes was 1050 mm(3) to 3880 mm(3). The amygdala is significantly larger in men and shows an inverse correlation with age. The main methodological factor found to influence amygdala measurement was anatomical definition. Studies using 'Watson's criteria' (Neurology 42 (1992) 1743) produced significantly larger volumes than the remainder. An index of study quality revealed an inverse relationship with volume-the higher the quality the smaller the volume. This reflected such factors as slice thickness, correction for brain volume, positional correction and number of subjects. We conclude by putting forward a detailed operationalized anatomical delineation of the amygdala, based on Watson's criteria. This work should guide future research in obtaining accurate and reliable amygdala volume measures which in turn will aid comparisons with clinical groups and the specification of structural-functional relationships.
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Affiliation(s)
- B Brierley
- Section of Cognitive Neuropsychiatry, Institute of Psychiatry, DeCrespigny Park, London SE5 8AF, UK
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