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Zhang TY, Keown CL, Wen X, Li J, Vousden DA, Anacker C, Bhattacharyya U, Ryan R, Diorio J, O'Toole N, Lerch JP, Mukamel EA, Meaney MJ. Environmental enrichment increases transcriptional and epigenetic differentiation between mouse dorsal and ventral dentate gyrus. Nat Commun 2018; 9:298. [PMID: 29352183 PMCID: PMC5775256 DOI: 10.1038/s41467-017-02748-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/19/2017] [Indexed: 01/01/2023] Open
Abstract
Early life experience influences stress reactivity and mental health through effects on cognitive-emotional functions that are, in part, linked to gene expression in the dorsal and ventral hippocampus. The hippocampal dentate gyrus (DG) is a major site for experience-dependent plasticity associated with sustained transcriptional alterations, potentially mediated by epigenetic modifications. Here, we report comprehensive DNA methylome, hydroxymethylome and transcriptome data sets from mouse dorsal and ventral DG. We find genome-wide transcriptional and methylation differences between dorsal and ventral DG, including at key developmental transcriptional factors. Peripubertal environmental enrichment increases hippocampal volume and enhances dorsal DG-specific differences in gene expression. Enrichment also enhances dorsal-ventral differences in DNA methylation, including at binding sites of the transcription factor NeuroD1, a regulator of adult neurogenesis. These results indicate a dorsal-ventral asymmetry in transcription and methylation that parallels well-known functional and anatomical differences, and that may be enhanced by environmental enrichment.
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Affiliation(s)
- Tie-Yuan Zhang
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada.
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada.
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada.
| | - Christopher L Keown
- Department of Cognitive Science, University of California, 9500 Gilman Dr., La Jolla, San Diego, 92093, CA, USA
| | - Xianglan Wen
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
| | - Junhao Li
- Department of Cognitive Science, University of California, 9500 Gilman Dr., La Jolla, San Diego, 92093, CA, USA
| | - Dulcie A Vousden
- Department of Medical Biophysics, The Hospital for Sick Children, University of Toronto, Toronto, M5G 1X8, Canada
| | - Christoph Anacker
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
| | - Urvashi Bhattacharyya
- Department of Cognitive Science, University of California, 9500 Gilman Dr., La Jolla, San Diego, 92093, CA, USA
| | - Richard Ryan
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
| | - Josie Diorio
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
| | - Nicholas O'Toole
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
| | - Jason P Lerch
- Department of Medical Biophysics, The Hospital for Sick Children, University of Toronto, Toronto, M5G 1X8, Canada
| | - Eran A Mukamel
- Department of Cognitive Science, University of California, 9500 Gilman Dr., La Jolla, San Diego, 92093, CA, USA.
| | - Michael J Meaney
- Sackler Program for Epigenetics and Psychobiology, McGill University, Montréal, H4H 1R3, Canada
- Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montréal, H4H 1R3, Canada
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, 6875 boul. Lasalle, Montréal, H4H 1R3, Canada
- Singapore Institute for Clinical Sciences, Singapore, 117609, Singapore
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Abbott AE, Linke AC, Nair A, Jahedi A, Alba LA, Keown CL, Fishman I, Müller RA. Repetitive behaviors in autism are linked to imbalance of corticostriatal connectivity: a functional connectivity MRI study. Soc Cogn Affect Neurosci 2018; 13:32-42. [PMID: 29177509 PMCID: PMC5793718 DOI: 10.1093/scan/nsx129] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 10/03/2017] [Accepted: 10/23/2017] [Indexed: 01/17/2023] Open
Abstract
The neural underpinnings of repetitive behaviors (RBs) in autism spectrum disorders (ASDs), ranging from cognitive to motor characteristics, remain unknown. We assessed RB symptomatology in 50 ASD and 52 typically developing (TD) children and adolescents (ages 8-17 years), examining intrinsic functional connectivity (iFC) of corticostriatal circuitry, which is important for reward-based learning and integration of emotional, cognitive and motor processing, and considered impaired in ASDs. Connectivity analyses were performed for three functionally distinct striatal seeds (limbic, frontoparietal and motor). Functional connectivity with cortical regions of interest was assessed for corticostriatal circuit connectivity indices and ratios, testing the balance of connectivity between circuits. Results showed corticostriatal overconnectivity of limbic and frontoparietal seeds, but underconnectivity of motor seeds. Correlations with RBs were found for connectivity between the striatal motor seeds and cortical motor clusters from the whole-brain analysis, and for frontoparietal/limbic and motor/limbic connectivity ratios. Division of ASD participants into high (n = 17) and low RB subgroups (n = 19) showed reduced frontoparietal/limbic and motor/limbic circuit ratios for high RB compared to low RB and TD groups in the right hemisphere. Results suggest an association between RBs and an imbalance of corticostriatal iFC in ASD, being increased for limbic, but reduced for frontoparietal and motor circuits.
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Affiliation(s)
- Angela E Abbott
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
| | - Annika C Linke
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
| | - Aarti Nair
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
- Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, San Diego, CA, USA
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, USA
| | - Afrooz Jahedi
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
- Computational Science Research Center, San Diego State University
| | - Laura A Alba
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
| | - Christopher L Keown
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
- Computational Science Research Center, San Diego State University
- Department of Cognitive Science, University of California, San Diego, CA, USA
| | - Inna Fishman
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
- Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, San Diego, CA, USA
| | - Ralph-Axel Müller
- Department of Psychology, Brain Development Imaging Laboratories, San Diego State University
- Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, San Diego, CA, USA
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3
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Luo C, Keown CL, Kurihara L, Zhou J, He Y, Li J, Castanon R, Lucero J, Nery JR, Sandoval JP, Bui B, Sejnowski TJ, Harkins TT, Mukamel EA, Behrens MM, Ecker JR. Single-cell methylomes identify neuronal subtypes and regulatory elements in mammalian cortex. Science 2017; 357:600-604. [PMID: 28798132 DOI: 10.1126/science.aan3351] [Citation(s) in RCA: 311] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/13/2017] [Indexed: 12/22/2022]
Abstract
The mammalian brain contains diverse neuronal types, yet we lack single-cell epigenomic assays that are able to identify and characterize them. DNA methylation is a stable epigenetic mark that distinguishes cell types and marks regulatory elements. We generated >6000 methylomes from single neuronal nuclei and used them to identify 16 mouse and 21 human neuronal subpopulations in the frontal cortex. CG and non-CG methylation exhibited cell type-specific distributions, and we identified regulatory elements with differential methylation across neuron types. Methylation signatures identified a layer 6 excitatory neuron subtype and a unique human parvalbumin-expressing inhibitory neuron subtype. We observed stronger cross-species conservation of regulatory elements in inhibitory neurons than in excitatory neurons. Single-nucleus methylomes expand the atlas of brain cell types and identify regulatory elements that drive conserved brain cell diversity.
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Affiliation(s)
- Chongyuan Luo
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.,Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Christopher L Keown
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92037, USA
| | - Laurie Kurihara
- Swift Biosciences Inc., 58 Parkland Plaza, Suite 100, Ann Arbor, MI 48103, USA
| | - Jingtian Zhou
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.,Bioinformatics and Systems Biology Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yupeng He
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.,Bioinformatics and Systems Biology Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Junhao Li
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92037, USA
| | - Rosa Castanon
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Jacinta Lucero
- Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Joseph R Nery
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Justin P Sandoval
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Brian Bui
- Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Terrence J Sejnowski
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.,Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy T Harkins
- Swift Biosciences Inc., 58 Parkland Plaza, Suite 100, Ann Arbor, MI 48103, USA
| | - Eran A Mukamel
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92037, USA.
| | - M Margarita Behrens
- Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Joseph R Ecker
- Genomic Analysis Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA. .,Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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Keown CL, Datko MC, Chen CP, Maximo JO, Jahedi A, Müller RA. Network organization is globally atypical in autism: A graph theory study of intrinsic functional connectivity. Biol Psychiatry Cogn Neurosci Neuroimaging 2017; 2:66-75. [PMID: 28944305 DOI: 10.1016/j.bpsc.2016.07.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Despite abundant evidence of brain network anomalies in autism spectrum disorder (ASD), findings have varied from broad functional underconnectivity to broad overconnectivity. Rather than pursuing overly simplifying general hypotheses ('under' vs. 'over'), we tested the hypothesis of atypical network distribution in ASD (i.e., participation of unusual loci in distributed functional networks). METHODS We used a selective high-quality data subset from the ABIDE datashare (including 111 ASD and 174 typically developing [TD] participants) and several graph theory metrics. Resting state functional MRI data were preprocessed and analyzed for detection of low-frequency intrinsic signal correlations. Groups were tightly matched for available demographics and head motion. RESULTS As hypothesized, the Rand Index (reflecting how similar network organization was to a normative set of networks) was significantly lower in ASD than TD participants. This was accounted for by globally reduced cohesion and density, but increased dispersion of networks. While differences in hub architecture did not survive correction, rich club connectivity (among the hubs) was increased in the ASD group. CONCLUSIONS Our findings support the model of reduced network integration (connectivity with networks) and differentiation (or segregation; based on connectivity outside network boundaries) in ASD. While the findings applied at the global level, they were not equally robust across all networks and in one case (greater cohesion within ventral attention network in ASD) even reversed.
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Affiliation(s)
- Christopher L Keown
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States.,Department of Cognitive Science, University of California, San Diego, CA
| | - Michael C Datko
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States.,Department of Cognitive Science, University of California, San Diego, CA
| | - Colleen P Chen
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States.,Computational Science Research Center, San Diego State University, San Diego, CA
| | - José Omar Maximo
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States
| | - Afrooz Jahedi
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States.,Department of Mathematics and Statistics, San Diego State University, San Diego, CA, United States
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States
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Abbott AE, Nair A, Keown CL, Datko M, Jahedi A, Fishman I, Müller RA. Patterns of Atypical Functional Connectivity and Behavioral Links in Autism Differ Between Default, Salience, and Executive Networks. Cereb Cortex 2016; 26:4034-45. [PMID: 26351318 PMCID: PMC5027998 DOI: 10.1093/cercor/bhv191] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is characterized by atypical brain network organization, but findings have been inconsistent. While methodological and maturational factors have been considered, the network specificity of connectivity abnormalities remains incompletely understood. We investigated intrinsic functional connectivity (iFC) for four "core" functional networks-default-mode (DMN), salience (SN), and left (lECN) and right executive control (rECN). Resting-state functional MRI data from 75 children and adolescents (37 ASD, 38 typically developing [TD]) were included. Functional connectivity within and between networks was analyzed for regions of interest (ROIs) and whole brain, compared between groups, and correlated with behavioral scores. ROI analyses showed overconnectivity (ASD > TD), especially between DMN and ECN. Whole-brain results were mixed. While predominant overconnectivity was found for DMN (posterior cingulate seed) and rECN (right inferior parietal seed), predominant underconnectivity was found for SN (right anterior insula seed) and lECN (left inferior parietal seed). In the ASD group, reduced SN integrity was associated with sensory and sociocommunicative symptoms. In conclusion, atypical connectivity in ASD is network-specific, ranging from extensive overconnectivity (DMN, rECN) to extensive underconnectivity (SN, lECN). Links between iFC and behavior differed between groups. Core symptomatology in the ASD group was predominantly related to connectivity within the salience network.
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Affiliation(s)
- Angela E. Abbott
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Aarti Nair
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
- Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, CA, USA
| | - Christopher L. Keown
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
- Department of Cognitive Science, University of California, San Diego, CA, USA
| | - Michael Datko
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
- Department of Cognitive Science, University of California, San Diego, CA, USA
| | - Afrooz Jahedi
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
| | - Inna Fishman
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA
- Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, CA, USA
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Shen MD, Li DD, Keown CL, Lee A, Johnson RT, Angkustsiri K, Rogers SJ, Müller RA, Amaral DG, Nordahl CW. Functional Connectivity of the Amygdala Is Disrupted in Preschool-Aged Children With Autism Spectrum Disorder. J Am Acad Child Adolesc Psychiatry 2016; 55:817-24. [PMID: 27566123 PMCID: PMC5003422 DOI: 10.1016/j.jaac.2016.05.020] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/15/2016] [Accepted: 06/22/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE The objective of this study was to determine whether functional connectivity of the amygdala is altered in preschool-age children with autism spectrum disorder (ASD) and to assess the clinical relevance of observed alterations in amygdala connectivity. METHOD A resting-state functional connectivity magnetic resonance imaging study of the amygdala (and a parallel study of primary visual cortex) was conducted in 72 boys (mean age 3.5 years; n = 43 with ASD; n = 29 age-matched controls). RESULTS The ASD group showed significantly weaker connectivity between the amygdala and several brain regions involved in social communication and repetitive behaviors, including bilateral medial prefrontal cortex, temporal lobes, and striatum (p < .05, corrected). Weaker connectivity between the amygdala and frontal and temporal lobes was significantly correlated with increased autism severity in the ASD group (p < .05). In a parallel analysis examining the functional connectivity of primary visual cortex, the ASD group showed significantly weaker connectivity between visual cortex and sensorimotor regions (p < .05, corrected). Weaker connectivity between visual cortex and sensorimotor regions was not correlated with core autism symptoms, but instead was correlated with increased sensory hypersensitivity in the visual/auditory domain (p < .05). CONCLUSION These findings indicate that preschool-age children with ASD have disrupted functional connectivity between the amygdala and regions of the brain important for social communication and language, which might be clinically relevant because weaker connectivity was associated with increased autism severity. Moreover, although amygdala connectivity was associated with behavioral domains that are diagnostic of ASD, altered connectivity of primary visual cortex was related to sensory hypersensitivity.
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Affiliation(s)
- Mark D. Shen
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Deana D. Li
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Christopher L. Keown
- Brain Development Imaging Laboratory at San Diego State University, San Diego, CA.,University of California, San Diego, La Jolla, CA
| | - Aaron Lee
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Ryan T. Johnson
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Kathleen Angkustsiri
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Sally J. Rogers
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory at San Diego State University, San Diego, CA
| | - David G. Amaral
- MIND Institute and the University of California at Davis School of Medicine in Sacramento, CA
| | - Christine Wu Nordahl
- MIND Institute and the University of California Davis School of Medicine in Sacramento.
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Khan AJ, Nair A, Keown CL, Datko MC, Lincoln AJ, Müller RA. Cerebro-cerebellar Resting-State Functional Connectivity in Children and Adolescents with Autism Spectrum Disorder. Biol Psychiatry 2015; 78:625-34. [PMID: 25959247 PMCID: PMC5708535 DOI: 10.1016/j.biopsych.2015.03.024] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 03/17/2015] [Accepted: 03/20/2015] [Indexed: 12/28/2022]
Abstract
BACKGROUND The cerebellum plays important roles in sensori-motor and supramodal cognitive functions. Cellular, volumetric, and functional abnormalities of the cerebellum have been found in autism spectrum disorders (ASD), but no comprehensive investigation of cerebro-cerebellar connectivity in ASD is available. METHODS We used resting-state functional connectivity magnetic resonance imaging in 56 children and adolescents (28 subjects with ASD, 28 typically developing subjects) 8-17 years old. Partial and total correlation analyses were performed for unilateral regions of interest (ROIs), distinguished in two broad domains as sensori-motor (premotor/primary motor, somatosensory, superior temporal, and occipital) and supramodal (prefrontal, posterior parietal, and inferior and middle temporal). RESULTS There were three main findings: 1) Total correlation analyses showed predominant cerebro-cerebellar functional overconnectivity in the ASD group; 2) partial correlation analyses that emphasized domain specificity (sensori-motor vs. supramodal) indicated a pattern of robustly increased connectivity in the ASD group (compared with the typically developing group) for sensori-motor ROIs but predominantly reduced connectivity for supramodal ROIs; and 3) this atypical pattern of connectivity was supported by significantly increased noncanonical connections (between sensori-motor cerebral and supramodal cerebellar ROIs and vice versa) in the ASD group. CONCLUSIONS Our findings indicate that sensori-motor intrinsic functional connectivity is atypically increased in ASD, at the expense of connectivity supporting cerebellar participation in supramodal cognition.
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Affiliation(s)
- Amanda J Khan
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California
| | - Aarti Nair
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.; Joint Doctoral Program in Language and Communicative Disorders, San Diego State University and University of California, San Diego, California
| | - Christopher L Keown
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.; Department of Cognitive Science, University of California, San Diego, California
| | - Michael C Datko
- Department of Cognitive Science, University of California, San Diego, California
| | - Alan J Lincoln
- Department of Clinical Psychology, Alliant International University, San Diego, California
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California..
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Abstract
IMPORTANCE Converging evidence indicates that brain abnormalities in autism spectrum disorder (ASD) involve atypical network connectivity, but it is unclear whether altered connectivity is especially prominent in brain networks that participate in social cognition. OBJECTIVE To investigate whether adolescents with ASD show altered functional connectivity in 2 brain networks putatively impaired in ASD and involved in social processing, theory of mind (ToM) and mirror neuron system (MNS). DESIGN, SETTING, AND PARTICIPANTS Cross-sectional study using resting-state functional magnetic resonance imaging involving 25 adolescents with ASD between the ages of 11 and 18 years and 25 typically developing adolescents matched for age, handedness, and nonverbal IQ. MAIN OUTCOMES AND MEASURES Statistical parametric maps testing the degree of whole-brain functional connectivity and social functioning measures. RESULTS Relative to typically developing controls, participants with ASD showed a mixed pattern of both over- and underconnectivity in the ToM network, which was associated with greater social impairment. Increased connectivity in the ASD group was detected primarily between the regions of the MNS and ToM, and was correlated with sociocommunicative measures, suggesting that excessive ToM-MNS cross talk might be associated with social impairment. In a secondary analysis comparing a subset of the 15 participants with ASD with the most severe symptomology and a tightly matched subset of 15 typically developing controls, participants with ASD showed exclusive overconnectivity effects in both ToM and MNS networks, which were also associated with greater social dysfunction. CONCLUSIONS AND RELEVANCE Adolescents with ASD showed atypically increased functional connectivity involving the mentalizing and mirror neuron systems, largely reflecting greater cross talk between the 2. This finding is consistent with emerging evidence of reduced network segregation in ASD and challenges the prevailing theory of general long-distance underconnectivity in ASD. This excess ToM-MNS connectivity may reflect immature or aberrant developmental processes in 2 brain networks involved in understanding of others, a domain of impairment in ASD. Further, robust links with sociocommunicative symptoms of ASD implicate atypically increased ToM-MNS connectivity in social deficits observed in ASD.
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Affiliation(s)
- Inna Fishman
- San Diego State University, San Diego, California
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Nair A, Keown CL, Datko M, Shih P, Keehn B, Müller RA. Impact of methodological variables on functional connectivity findings in autism spectrum disorders. Hum Brain Mapp 2014; 35:4035-48. [PMID: 24452854 DOI: 10.1002/hbm.22456] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/26/2013] [Accepted: 12/12/2013] [Indexed: 11/10/2022] Open
Abstract
Growing evidence suggests that Autism Spectrum Disorder (ASD) involves abnormalities of multiple functional networks. Neuroimaging studies of ASD have therefore increasingly focused on connectivity. Many functional connectivity (fcMRI) studies have reported network underconnectivity in children and adults with ASD. However, there are notable inconsistencies, with some studies reporting overconnectivity. A previous literature survey suggested that a few methodological factors play a crucial role in differential fcMRI outcomes. Using three ASD data sets (two task-related, one resting state) from 54 ASD and 51 typically developing (TD) participants (ages 9-18 years), we examined the impact of four methodological factors: type of pipeline (co-activation vs. intrinsic analysis, related to temporal filtering and removal of task-related effects), seed selection, field of view (whole brain vs. limited ROIs), and dataset. Significant effects were found for type of pipeline, field of view, and dataset. Notably, for each dataset results ranging from robust underconnectivity to robust overconnectivity were detected, depending on the type of pipeline, with intrinsic fcMRI analyses (low bandpass filter and task regressor) predominantly yielding overconnectivity in ASD, but co-activation analyses (no low bandpass filter or task removal) mostly generating underconnectivity findings. These results suggest that methodological variables have dramatic impact on group differences reported in fcMRI studies. Improved awareness of their implications appears indispensible in fcMRI studies when inferences about "underconnectivity" or "overconnectivity" in ASD are made. In the absence of a gold standard for functional connectivity, the combination of different methodological approaches promises a more comprehensive understanding of connectivity in ASD.
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Affiliation(s)
- Aarti Nair
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California; Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, California
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10
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Maximo JO, Keown CL, Nair A, Müller RA. Approaches to local connectivity in autism using resting state functional connectivity MRI. Front Hum Neurosci 2013; 7:605. [PMID: 24155702 PMCID: PMC3792552 DOI: 10.3389/fnhum.2013.00605] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/05/2013] [Indexed: 11/13/2022] Open
Abstract
While the literature on aberrant long-distance connectivity in autism spectrum disorder (ASD) has grown fast over the past decade, little is known about local connectivity. We used regional homogeneity and local density approaches at different spatial scales to examine local connectivity in 29 children and adolescents with ASD and 29 matched typically developing participants, using resting state functional magnetic resonance imaging data. Across a total of 12 analysis pipelines, the gross pattern of between-group findings was overall stable, with local overconnectivity in the ASD group in occipital and posterior temporal regions and underconnectivity in middle/posterior cingulate, and medial prefrontal regions. This general pattern was confirmed in secondary analyses for low-motion subsamples (n = 20 per group), in which time series segments with >0.25 mm head motion were censored, as well as in an analysis including global signal regression. Local overconnectivity in visual regions appears consistent with preference for local over global visual processing previously reported in ASD, whereas cingulate and medial frontal underconnectivity may relate to aberrant function within the default mode network.
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Affiliation(s)
- Jose O Maximo
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University San Diego, CA, USA
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Müller RA, Shih P, Keown CL. A functional connectivity-based classification approach to autism spectrum disorder: only as good (or bad) as available diagnostic criteria. Future Neurology 2012. [DOI: 10.2217/fnl.12.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Evaluation of: Anderson JS, Nielsen JA, Froehlich AL et al. Functional connectivity magnetic resonance imaging classification of autism. Brain 134, 3742–3754 (2011). This study used functional connectivity detected from low-frequency fluctuations in functional MRI time series acquired during a resting state. Participants were adolescents and adults with autism spectrum disorder (ASD) and typically developing controls. Classification scores were used to predict group membership based on functional connectivity for a large number of regions of interest across the whole brain. Diagnostic prediction accuracy was approximately 75% overall. The results contribute to current knowledge of functional connectivity abnormalities in ASD, generally in support of underconnectivity theories. They are also promising with respect to the search for biomarkers of ASD that are needed to replace current behavior-based diagnostic criteria. While data from young children were not available for this study, findings appear to suggest that functional connectivity signatures may be more distinctively abnormal in children compared to adults with ASD.
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Affiliation(s)
- Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA; Department of Psychology, San Diego State University, 6363 Alvarado Ct., Suite 200, San Diego, CA 92120, USA
| | - Patricia Shih
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Christopher L Keown
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, USA; Department of Psychology, San Diego State University, 6363 Alvarado Ct., Suite 200, San Diego, CA 92120, USA
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
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Shih P, Keehn B, Oram JK, Leyden KM, Keown CL, Müller RA. Functional differentiation of posterior superior temporal sulcus in autism: a functional connectivity magnetic resonance imaging study. Biol Psychiatry 2011; 70:270-7. [PMID: 21601832 PMCID: PMC3335267 DOI: 10.1016/j.biopsych.2011.03.040] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 03/04/2011] [Accepted: 03/22/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Socio-communicative impairments are salient features of autism spectrum disorder (ASD). Abnormal development of posterior superior temporal sulcus (pSTS)--a key processing area for language, biological motion, and social context--could play a role in these deficits. METHODS Functional connectivity magnetic resonance imaging was used to examine the synchronization of low-frequency blood oxygen level-dependent fluctuations during continuous performance on a visual search task. Twenty-one children and adolescents with ASD and 26 typically developing individuals-matched on age and IQ-participated in the study. Three subregions of pSTS were delineated with a data-driven approach, and differentiation of pSTS was examined by comparing the connectivity of each subregion. RESULTS In typically developing individuals, differentiation of networks was positively associated with age and anatomical maturation (cortical thinning in pSTS, greater white matter volume). In the ASD group, differentiation of pSTS connectivity was significantly reduced, and correlations with anatomical measures were weak or absent. Moreover, pSTS differentiation was inversely correlated with autism symptom severity. CONCLUSIONS Atypical maturation of pSTS suggests altered trajectories for functional segregation and integration of networks in ASD, potentially related to impaired cognitive and sensorimotor development. Furthermore, our findings provide a novel explanation for atypically increased connectivity in ASD that has been observed in some functional connectivity magnetic resonance imaging studies.
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Affiliation(s)
- Patricia Shih
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, USA
| | - Brandon Keehn
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, USA,Joint Doctoral Program in Language and Communicative Disorders, San Diego State University, San Diego, CA 92120 and University of California, San Diego, La Jolla, CA 92093, USA
| | - Jessica K. Oram
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, USA
| | - Kelly M. Leyden
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, USA
| | - Christopher L. Keown
- Computational Sciences Program, San Diego State University, San Diego, CA 92120, USA
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, USA,Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92093, USA
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