401
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Abstract
Atypical trajectory of brain growth in autism spectrum disorders (ASDs) has been recognized as a potential etiology of an atypical course of behavioral development. Numerous neuroimaging studies have focused on childhood to investigate atypical age-related change of brain structure and function, because it is a period of neuron and synapse maturation. Recent studies, however, have shown that the atypical age-related structural change of autistic brain expands beyond childhood and constitutes neural underpinnings for lifelong difficulty to behavioral adaptation. Thus, we examined effects of aging on neurochemical aspects of brain maturation using 3-T proton magnetic resonance spectroscopy ((1)H-MRS) with single voxel in the medial prefrontal cortex (PFC) in 24 adult men with non-medicated high-functioning ASDs and 25 age-, IQ- and parental-socioeconomic-background-matched men with typical development (TD). Multivariate analyses of covariance demonstrated significantly high N-acetylaspartate (NAA) level in the ASD subjects compared with the TD subjects (F=4.83, P=0.033). The low NAA level showed a significant positive correlation with advanced age in the TD group (r=-0.618, P=0.001), but was not evident among the ASD individuals (r=0.258, P=0.223). Fisher's r-to-z transformation showed a significant difference in the correlations between the ASD and TD groups (Z=-3.23, P=0.001), which indicated that the age-NAA relationship was significantly specific to people with TD. The current (1)H-MRS study provided new evidence that atypical age-related change of neurochemical aspects of brain maturation in ASD individuals expands beyond childhood and persists during adulthood.
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402
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Jordan I, Robertson D, Catani M, Craig M, Murphy D. Aripiprazole in the treatment of challenging behaviour in adults with autism spectrum disorder. Psychopharmacology (Berl) 2012; 223:357-60. [PMID: 22535309 DOI: 10.1007/s00213-012-2723-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 04/09/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Autism spectrum disorders (ASD) are associated with repetitive behaviours and often also with hyperactivity, aggression, self-injurious behaviour, irritability and lability of mood. There is emerging evidence that aripiprazole, an antipsychotic with partial agonist dopaminergic effect, may be effective in the treatment of these challenging behaviours. Nevertheless, there is little evidence for their efficacy in adults with ASD. OBJECTIVES The aim of this article is to present preliminary data on the use of aripiprazole in the treatment of challenging behaviour in the setting of ASD. METHODS We present a consecutive series of five inpatients of normal intelligence with challenging behaviour associated with ASD, diagnosed according to ICD-10 criteria, which was resistant to treatment with other medical and behavioural interventions and which was treated with aripiprazole. RESULTS Four out of five patients were classified as "much improved" or "very much improved" according to the Clinical Global Impression-Improvement scale. Aripiprazole caused akathisia, at a dose of 30 mg in the one patient who was not classified as a responder but was otherwise well tolerated. CONCLUSIONS This is the first case series of adults with ASD presenting with challenging behaviour who have been treated with aripiprazole. While the results are promising, controlled trials are required to confirm the findings.
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Affiliation(s)
- Iain Jordan
- Department of Forensic and Neurodevelopmental Science, Institute of Psychiatry, 16 De Crespigny Park, London, SE5 8AF, UK.
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403
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Smith JM, Xu J, Powell EM. Age dependent forebrain structural changes in mice deficient in the autism associated gene Met tyrosine kinase. Neuroimage Clin 2012; 1:66-74. [PMID: 24179738 PMCID: PMC3757733 DOI: 10.1016/j.nicl.2012.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/13/2012] [Accepted: 09/03/2012] [Indexed: 01/06/2023]
Abstract
The MET tyrosine kinase has been identified as a susceptibility gene in patients with autism spectrum disorders. MET is expressed in the forebrain during prenatal and postnatal development. After birth, MET participates in dendritic outgrowth and circuit formation. Alterations in neuronal development, particularly in the cerebral cortex, may contribute to the pathology of developmental disorders, including autism. Patients with autism can exhibit abnormal cortical volumes and head circumferences. We tested the hypothesis that impaired Met signaling during development alters forebrain structure. We have utilized a conditional mutant mouse line which expresses a kinase-dead Met restricted to the cerebral cortex and hippocampal structures. In these mice, we have used magnetic resonance imaging (MRI) to analyze the structure of the cerebral cortex and related structures across postnatal development. We found that the rostral cortex, caudal hippocampus, dorsal striatum, thalamus, and corpus callosum were all larger in adult, but not juvenile, mutant mice relative to control mice. The specificity of the changes suggests that aberrant expansion of the forebrain is consistent with continued axonal and dendritic growth, potentially leading to improper circuit formation and maintenance.
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Key Words
- ANOVA, analysis of variance
- Autism
- CC, corpus callosum
- Corpus callosum
- Frontal cortex
- H,hipp, hippocampus
- HGF, hepatocyte growth factor
- K–S, Kolmogorov–Smirnov
- MRI
- MRI, magnetic resonance imaging
- Met tyrosine kinase
- Mouse
- P, postnatal day
- PCR, polymerase chain reaction
- RARE, rapid acquisition relaxation enhancement
- SEM, standard error of the mean
- bp, base pairs
- ctx, cerebral cortex
- mm, millimeter
- str, striatum
- th,thal, thalamus
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Affiliation(s)
- Jacob M. Smith
- Program in Neuroscience, Graduate Program in Life Sciences, Graduate School, University of Maryland, Baltimore, MD, USA
| | - Jennifer Xu
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Elizabeth M. Powell
- Program in Neuroscience, Graduate Program in Life Sciences, Graduate School, University of Maryland, Baltimore, MD, USA
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
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404
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Foley AG, Gannon S, Rombach-Mullan N, Prendergast A, Barry C, Cassidy AW, Regan CM. Class I histone deacetylase inhibition ameliorates social cognition and cell adhesion molecule plasticity deficits in a rodent model of autism spectrum disorder. Neuropharmacology 2012; 63:750-60. [DOI: 10.1016/j.neuropharm.2012.05.042] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 05/24/2012] [Accepted: 05/25/2012] [Indexed: 12/19/2022]
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405
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Brown TT, Kuperman JM, Chung Y, Erhart M, McCabe C, Hagler DJ, Venkatraman VK, Akshoomoff N, Amaral DG, Bloss CS, Casey BJ, Chang L, Ernst TM, Frazier JA, Gruen JR, Kaufmann WE, Kenet T, Kennedy DN, Murray SS, Sowell ER, Jernigan TL, Dale AM. Neuroanatomical assessment of biological maturity. Curr Biol 2012; 22:1693-8. [PMID: 22902750 DOI: 10.1016/j.cub.2012.07.002] [Citation(s) in RCA: 250] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/20/2012] [Accepted: 07/02/2012] [Indexed: 11/25/2022]
Abstract
Structural MRI allows unparalleled in vivo study of the anatomy of the developing human brain. For more than two decades, MRI research has revealed many new aspects of this multifaceted maturation process, significantly augmenting scientific knowledge gathered from postmortem studies. Postnatal brain development is notably protracted and involves considerable changes in cerebral cortical, subcortical, and cerebellar structures, as well as significant architectural changes in white matter fiber tracts (see [12]). Although much work has described isolated features of neuroanatomical development, it remains a critical challenge to characterize the multidimensional nature of brain anatomy, capturing different phases of development among individuals. Capitalizing on key advances in multisite, multimodal MRI, and using cross-validated nonlinear modeling, we demonstrate that developmental brain phase can be assessed with much greater precision than has been possible using other biological measures, accounting for more than 92% of the variance in age. Further, our composite metric of morphology, diffusivity, and signal intensity shows that the average difference in phase among children of the same age is only about 1 year, revealing for the first time a latent phenotype in the human brain for which maturation timing is tightly controlled.
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Affiliation(s)
- Timothy T Brown
- Multimodal Imaging Laboratory, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA.
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406
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Meyza KZ, Defensor EB, Jensen AL, Corley MJ, Pearson BL, Pobbe RLH, Bolivar VJ, Blanchard DC, Blanchard RJ. The BTBR T+ tf/J mouse model for autism spectrum disorders-in search of biomarkers. Behav Brain Res 2012; 251:25-34. [PMID: 22958973 DOI: 10.1016/j.bbr.2012.07.021] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 07/11/2012] [Accepted: 07/12/2012] [Indexed: 12/28/2022]
Abstract
Autism spectrum disorders (ASD) form a common group of neurodevelopmental disorders appearing to be under polygenic control, but also strongly influenced by multiple environmental factors. The brain mechanisms responsible for ASD are not understood and animal models paralleling related emotional and cognitive impairments may prove helpful in unraveling them. BTBR T+ tf/J (BTBR) mice display behaviors consistent with the three diagnostic categories for ASD. They show impaired social interaction and communication as well as increased repetitive behaviors. This review covers much of the data available to date on BTBR behavior, neuroanatomy and physiology in search for candidate biomarkers, which could both serve as diagnostic tools and help to design effective treatments for the behavioral symptoms of ASD.
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Affiliation(s)
- Ksenia Z Meyza
- Pacific Biosciences Research Center, University of Hawaii, 1993 East-west Road, Honolulu, HI 96822, USA
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407
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Deoni SCL, Dean DC, O'Muircheartaigh J, Dirks H, Jerskey BA. Investigating white matter development in infancy and early childhood using myelin water faction and relaxation time mapping. Neuroimage 2012; 63:1038-53. [PMID: 22884937 PMCID: PMC3711836 DOI: 10.1016/j.neuroimage.2012.07.037] [Citation(s) in RCA: 257] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 07/13/2012] [Accepted: 07/19/2012] [Indexed: 01/08/2023] Open
Abstract
The elaboration of the myelinated white matter is essential for normal neurodevelopment, establishing and mediating rapid communication pathways throughout the brain. These pathways facilitate the synchronized communication required for higher order behavioral and cognitive functioning. Altered neural messaging (or ‘disconnectivity’) arising from abnormal white matter and myelin development may underlie a number of neurodevelopmental psychiatric disorders. Despite the vital role myelin plays, few imaging studies have specifically examined its maturation throughout early infancy and childhood. Thus, direct investigations of the relationship(s) between evolving behavioral and cognitive functions and the myelination of the supporting neural systems have been sparse. Further, without knowledge of the ‘normative’ developmental time-course, identification of early abnormalities associated with developmental disorders remains challenging. In this work, we examined the use of longitudinal (T1) and transverse (T2) relaxation time mapping, and myelin water fraction (MWF) imaging to investigate white matter and myelin development in 153 healthy male and female children, 3 months through 60 months in age. Optimized age-specific acquisition protocols were developed using the DESPOT and mcDESPOT imaging techniques; and mean T1, T2 and MWF trajectories were determined for frontal, temporal, occipital, parietal and cerebellar white matter, and genu, body and splenium of the corpus callosum. MWF results provided a spatio-temporal pattern in-line with prior histological studies of myelination. Comparison of T1, T2 and MWF measurements demonstrates dissimilar sensitivity to tissue changes associated with neurodevelopment, with each providing differential but complementary information.
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Affiliation(s)
- Sean C L Deoni
- Advanced Baby Imaging Lab, School of Engineering, Brown University, Providence, RI, USA.
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408
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Abstract
The autistic spectrum disorders have a significant male bias in incidence, which is unexplained. The Sertoli cells of the immature testes secrete supra-adult levels of Müllerian-inhibiting substance/anti-Müllerian hormone (AMH) and inhibin B (InhB), with both hormones being putative regulators of brain development. We report here, that 82 boys with an autism spectrum disorder have normal levels of InhB and AMH. However, the boys' level of InhB correlated with their autism diagnostic interview-revised (ADI-R) scores for the social interaction (R=0.29, P=0.009, N=82) and communication domains (R=0.29, P=0.022, N=63), and with the number of autistic traits the boys exhibited (R=0.34 and 0.27, respectively). The strengths of the abovementioned correlates were stronger in the boys with milder autism (R=0.42 and 0.50, respectively), with AMH exhibiting a significant negative correlation to the ADI-R score in these boys (R=-0.44 and R=-0.39, respectively). Neither hormone correlated to the incidence of stereotyped and repetitive behaviours. This suggests that the male bias in the autistic spectrum has multiple determinants, which modulate the effects of an otherwise non-dimorphic pathology. Furthermore, AMH and InhB have opposing effects on the SMAD1/5/8 pathway, and opposing correlates to autistic traits, implicating the SMAD pathways as a putative point of molecular convergence for the autistic spectrum.
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409
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Kerin T, Ramanathan A, Rivas K, Grepo N, Coetzee GA, Campbell DB. A noncoding RNA antisense to moesin at 5p14.1 in autism. Sci Transl Med 2012; 4:128ra40. [PMID: 22491950 DOI: 10.1126/scitranslmed.3003479] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
People with autism spectrum disorder (ASD) are characterized by deficits in social interaction, language, and behavioral flexibility. Rare mutations and copy number variations have been identified in individuals with ASD, but in most patients, the causal variants remain unknown. A genome-wide association study (GWAS), designed to identify genes and pathways that contribute to ASD, indicated a genome-wide significant association of ASD with the single-nucleotide polymorphism (SNP) rs4307059 (P = 10⁻¹⁰), which is located in a gene-poor region of chromosome 5p14.1. We describe here a 3.9-kb noncoding RNA that is transcribed from the region of the chromosome 5p14.1 ASD GWAS association SNP. The noncoding RNA was encoded by the opposite (antisense) strand of moesin pseudogene 1 (MSNP1), and we therefore designated it as MSNP1AS (moesin pseudogene 1, antisense). Chromosome 5p14.1 MSNP1AS was 94% identical and antisense to the X chromosome transcript of MSN, which encodes a protein (moesin) that regulates neuronal architecture. Individuals who carry the ASD-associated rs4307059 T allele showed increased expression of MSNP1AS. The MSNP1AS noncoding RNA bound to MSN, was highly overexpressed (12.7-fold) in postmortem cerebral cortex of individuals with ASD, and could regulate levels of moesin protein in human cell lines. These data reveal a biologically functional element that may contribute to ASD risk.
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Affiliation(s)
- Tara Kerin
- Program in Biomedical and Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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410
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Jacot-Descombes S, Uppal N, Wicinski B, Santos M, Schmeidler J, Giannakopoulos P, Heinsen H, Schmitz C, Hof PR. Decreased pyramidal neuron size in Brodmann areas 44 and 45 in patients with autism. Acta Neuropathol 2012; 124:67-79. [PMID: 22467063 DOI: 10.1007/s00401-012-0976-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 03/22/2012] [Indexed: 11/28/2022]
Abstract
Autism is a neurodevelopmental disorder characterized by deficits in social interaction and social communication, as well as by the presence of repetitive and stereotyped behaviors and interests. Brodmann areas 44 and 45 in the inferior frontal cortex, which are involved in language processing, imitation function, and sociality processing networks, have been implicated in this complex disorder. Using a stereologic approach, this study aims to explore the presence of neuropathological differences in areas 44 and 45 in patients with autism compared to age- and hemisphere-matched controls. Based on previous evidence in the fusiform gyrus, we expected to find a decrease in the number and size of pyramidal neurons as well as an increase in volume of layers III, V, and VI in patients with autism. We observed significantly smaller pyramidal neurons in patients with autism compared to controls, although there was no difference in pyramidal neuron numbers or layer volumes. The reduced pyramidal neuron size suggests that a certain degree of dysfunction of areas 44 and 45 plays a role in the pathology of autism. Our results also support previous studies that have shown specific cellular neuropathology in autism with regionally specific reduction in neuron size, and provide further evidence for the possible involvement of the mirror neuron system, as well as impairment of neuronal networks relevant to communication and social behaviors, in this disorder.
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Affiliation(s)
- Sarah Jacot-Descombes
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1065, New York, NY 10029, USA
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411
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Enticott PG, Kennedy HA, Rinehart NJ, Tonge BJ, Bradshaw JL, Fitzgerald PB. GABAergic activity in autism spectrum disorders: an investigation of cortical inhibition via transcranial magnetic stimulation. Neuropharmacology 2012; 68:202-9. [PMID: 22727823 DOI: 10.1016/j.neuropharm.2012.06.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 05/11/2012] [Accepted: 06/11/2012] [Indexed: 10/28/2022]
Abstract
Mounting evidence suggests a possible role for γ-aminobutyric acid (GABA) in the neuropathophysiology of autism spectrum disorders (ASD), but the extent of this impairment is unclear. A non-invasive, in vivo measure of GABA involves transcranial magnetic stimulation (TMS) of the primary motor cortex to probe cortical inhibition. Individuals diagnosed with ASD (high-functioning autism or Asperger's disorder) (n = 36 [28 male]; mean age: 26.00 years) and a group of healthy individuals (n = 34 [23 male]; mean age: 26.21 years) (matched for age, gender, and cognitive function) were administered motor cortical TMS paradigms putatively measuring activity at GABAA and GABAB receptors (i.e., short and long interval paired pulse TMS, cortical silent period). All cortical inhibition paradigms yielded no difference between ASD and control groups. There was, however, evidence for short interval cortical inhibition (SICI) deficits among those ASD participants who had experienced early language delay, suggesting that GABA may be implicated in an ASD subtype. The current findings do not support a broad role for GABA in the neuropathophysiology of ASD, but provide further indication that GABAA could be involved in ASD where there is a delay in language acquisition. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.
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Affiliation(s)
- Peter G Enticott
- Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, St. Kilda Road, Melbourne, Victoria 3004, Australia.
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412
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Hazlett HC, Gu H, McKinstry RC, Shaw DW, Botteron KN, Dager S, Styner M, Vachet C, Gerig G, Paterson S, Schultz RT, Estes AM, Evans AC, Piven J. Brain volume findings in 6-month-old infants at high familial risk for autism. Am J Psychiatry 2012; 169:601-8. [PMID: 22684595 PMCID: PMC3744332 DOI: 10.1176/appi.ajp.2012.11091425] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Individuals with autism as young as 2 years have been observed to have larger brains than healthy comparison subjects. Studies using head circumference suggest that brain enlargement is a postnatal event that occurs around the latter part of the first year. To the authors' knowledge, no previous brain imaging studies have systematically examined the period prior to age 2. In this study they used magnetic resonance imaging (MRI) to measure brain volume in 6-month-olds at high familial risk for autism. METHOD The Infant Brain Imaging Study (IBIS) is a longitudinal imaging study of infants at high risk for autism. This cross-sectional analysis compared brain volumes at 6 months of age in high-risk infants (N=98) and infants without family members with autism (N=36). MRI scans were also examined for radiologic abnormalities RESULTS No group differences were observed for intracranial, cerebrum, cerebellum, or lateral ventricle volume or for head circumference. CONCLUSIONS The authors did not observe significant group differences for head circumference, brain volume, or abnormalities in radiologic findings from a group of 6-month-old infants at high risk for autism. The authors are unable to conclude that these abnormalities are not present in infants who later go on to receive a diagnosis of autism; rather, abnormalities were not detected in a large group at high familial risk. Future longitudinal studies of the IBIS study group will examine whether brain volume differs in infants who go on to develop autism.
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Affiliation(s)
- Heather Cody Hazlett
- Carolina Institute for Developmental Disabilities and the Department of Psychiatry, University of North Carolina, Chapel Hill, USA.
| | | | | | | | | | | | | | | | - Guido Gerig
- Scientific Computing Institute University of Utah
| | - Sarah Paterson
- Children’s Hospital of Philadelphia, University of Pennsylvania
| | | | | | | | - Joseph Piven
- University of North Carolina,Carolina Institute for Developmental Disabilities
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413
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Wolff JJ, Gu H, Gerig G, Elison JT, Styner M, Gouttard S, Botteron KN, Dager SR, Dawson G, Estes AM, Evans A, Hazlett HC, Kostopoulos P, McKinstry RC, Paterson SJ, Schultz RT, Zwaigenbaum L, Piven J. Differences in white matter fiber tract development present from 6 to 24 months in infants with autism. Am J Psychiatry 2012; 169:589-600. [PMID: 22362397 PMCID: PMC3377782 DOI: 10.1176/appi.ajp.2011.11091447] [Citation(s) in RCA: 459] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Evidence from prospective studies of high-risk infants suggests that early symptoms of autism usually emerge late in the first or early in the second year of life after a period of relatively typical development. The authors prospectively examined white matter fiber tract organization from 6 to 24 months in high-risk infants who developed autism spectrum disorders (ASDs) by 24 months. METHOD The participants were 92 high-risk infant siblings from an ongoing imaging study of autism. All participants had diffusion tensor imaging at 6 months and behavioral assessments at 24 months; a majority contributed additional imaging data at 12 and/or 24 months. At 24 months, 28 infants met criteria for ASDs and 64 infants did not. Microstructural properties of white matter fiber tracts reported to be associated with ASDs or related behaviors were characterized by fractional anisotropy and radial and axial diffusivity. RESULTS The fractional anisotropy trajectories for 12 of 15 fiber tracts differed significantly between the infants who developed ASDs and those who did not. Development for most fiber tracts in the infants with ASDs was characterized by higher fractional anisotropy values at 6 months followed by slower change over time relative to infants without ASDs. Thus, by 24 months of age, those with ASDs had lower values. CONCLUSIONS These results suggest that aberrant development of white matter pathways may precede the manifestation of autistic symptoms in the first year of life. Longitudinal data are critical to characterizing the dynamic age-related brain and behavior changes underlying this neurodevelopmental disorder.
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Affiliation(s)
- Jason J. Wolff
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC
| | - Hongbin Gu
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Department of Psychiatry, University of North Carolina, Chapel Hill, NC
| | - Guido Gerig
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Jed T. Elison
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, CA
| | - Martin Styner
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Department of Psychiatry, University of North Carolina, Chapel Hill, NC
| | - Sylvain Gouttard
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Kelly N. Botteron
- Department of Psychiatry, Washington University, St. Louis, MO,Department of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | | | - Geraldine Dawson
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC,Autism Speaks, New York, NY
| | - Annette M. Estes
- Department of Speech and Hearing Sciences, University of Washington, Seattle, WA
| | - Alan Evans
- Montreal Neurological Institute, McGill University, Montreal, QC
| | - Heather C. Hazlett
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Department of Psychiatry, University of North Carolina, Chapel Hill, NC
| | | | - Robert C. McKinstry
- Department of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | - Sarah J. Paterson
- Center for Autism Research, Children’s Hospital of Philadelphia, and University of Pennsylvania PA
| | - Robert T. Schultz
- Center for Autism Research, Children’s Hospital of Philadelphia, and University of Pennsylvania PA
| | | | - Joe Piven
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC,Department of Psychiatry, University of North Carolina, Chapel Hill, NC
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414
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Janušonis S. Direct interaction with no correlation: An experimental pitfall in neural systems. J Neurosci Methods 2012; 206:151-7. [DOI: 10.1016/j.jneumeth.2012.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/11/2012] [Accepted: 02/14/2012] [Indexed: 12/11/2022]
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415
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Longitudinal in-vivo diffusion tensor imaging for assessing brain developmental changes in BALB/cJ mice, a model of reduced sociability relevant to autism. Brain Res 2012; 1455:56-67. [PMID: 22513103 DOI: 10.1016/j.brainres.2012.03.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 02/17/2012] [Accepted: 03/18/2012] [Indexed: 11/24/2022]
Abstract
Diffusion tensor imaging (DTI) is highly sensitive in detecting brain structure and connectivity phenotypes in autism spectrum disorders (ASD). Since one of the core symptoms of ASD is reduced sociability (reduced tendency to seek social interaction), we hypothesized that DTI will be sensitive in detecting neural phenotypes that correlate with decreased sociability in mouse models. Relative to C57BL/6J (B6) mice, juvenile BALB/cJ mice show reduced sociability. We performed social approach test in a three-chambered apparatus and in-vivo longitudinal DTI at post-natal days 30, 50 and 70 days-of-age in BALB/cJ (n=32) and B6 (n=15) mice to assess the correlation between DTI and sociability and to evaluate differences in DTI parameters between these two strains. Fractional anisotropy (FA) and mean diffusivity (MD) values from in-vivo DTI data were analyzed from white matter (corpus callosum, internal and external capsule) and gray matter (cerebral cortex, frontal motor cortex, hippocampus, thalamus and amygdaloid) regions based on their relevance to ASD. A moderate but significant (p<0.05) negative correlation between sociability and FA in hippocampus and frontal motor cortex was noted for BALB/cJ mice at 30 days-of-age. Significant differences in FA and MD values between BALB/cJ and B6 mice were observed in most white and gray matter areas at all three time points. Significant differences in developmental trajectories of FA and MD values from thalamus and frontal motor cortex were also observed between BALB/cJ and B6, indicating relative under-connectivity in BALB/cJ mice. These results indicate that DTI may be used as an in-vivo, non-invasive imaging method to assess developmental trajectories of brain connectivity in mouse models of neurodevelopmental and behavioral disorders.
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416
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Chow ML, Pramparo T, Winn ME, Barnes CC, Li HR, Weiss L, Fan JB, Murray S, April C, Belinson H, Fu XD, Wynshaw-Boris A, Schork NJ, Courchesne E. Age-dependent brain gene expression and copy number anomalies in autism suggest distinct pathological processes at young versus mature ages. PLoS Genet 2012; 8:e1002592. [PMID: 22457638 PMCID: PMC3310790 DOI: 10.1371/journal.pgen.1002592] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 01/22/2012] [Indexed: 01/09/2023] Open
Abstract
Autism is a highly heritable neurodevelopmental disorder, yet the genetic underpinnings of the disorder are largely unknown. Aberrant brain overgrowth is a well-replicated observation in the autism literature; but association, linkage, and expression studies have not identified genetic factors that explain this trajectory. Few studies have had sufficient statistical power to investigate whole-genome gene expression and genotypic variation in the autistic brain, especially in regions that display the greatest growth abnormality. Previous functional genomic studies have identified possible alterations in transcript levels of genes related to neurodevelopment and immune function. Thus, there is a need for genetic studies involving key brain regions to replicate these findings and solidify the role of particular functional pathways in autism pathogenesis. We therefore sought to identify abnormal brain gene expression patterns via whole-genome analysis of mRNA levels and copy number variations (CNVs) in autistic and control postmortem brain samples. We focused on prefrontal cortex tissue where excess neuron numbers and cortical overgrowth are pronounced in the majority of autism cases. We found evidence for dysregulation in pathways governing cell number, cortical patterning, and differentiation in young autistic prefrontal cortex. In contrast, adult autistic prefrontal cortex showed dysregulation of signaling and repair pathways. Genes regulating cell cycle also exhibited autism-specific CNVs in DNA derived from prefrontal cortex, and these genes were significantly associated with autism in genome-wide association study datasets. Our results suggest that CNVs and age-dependent gene expression changes in autism may reflect distinct pathological processes in the developing versus the mature autistic prefrontal cortex. Our results raise the hypothesis that genetic dysregulation in the developing brain leads to abnormal regional patterning, excess prefrontal neurons, cortical overgrowth, and neural dysfunction in autism. Autism is a disorder characterized by aberrant social, communication, and restricted and repetitive behaviors. It develops clinically in the first years of life. Toddlers and children with autism often exhibit early brain enlargement and excess neuron numbers in the prefrontal cortex. Adults with autism generally do not display enlargement but instead may have a smaller brain size. Thus, we investigated DNA and mRNA patterns in prefrontal cortex from young versus adult postmortem individuals with autism to identify age-related gene expression differences as well as possible genetic correlates of abnormal brain enlargement, excess neuron numbers, and abnormal functioning in this disorder. We found abnormalities in genetic pathways governing cell number, neurodevelopment, and cortical lateralization in autism. We also found that the key pathways associated with autism are different between younger and older autistic individuals. These findings suggest that dysregulated gene pathways in the early stages of neurodevelopment could lead to later behavioral and cognitive deficits associated with autism.
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Affiliation(s)
- Maggie L. Chow
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Tiziano Pramparo
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Mary E. Winn
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
- Graduate Program in Biomedical Sciences, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Cynthia Carter Barnes
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Hai-Ri Li
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Lauren Weiss
- Department of Psychiatry, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Jian-Bing Fan
- Illumina, San Diego, California, United States of America
| | - Sarah Murray
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
| | - Craig April
- Illumina, San Diego, California, United States of America
| | - Haim Belinson
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Anthony Wynshaw-Boris
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Nicholas J. Schork
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
- * E-mail: (NJS); (EC)
| | - Eric Courchesne
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (NJS); (EC)
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417
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Flood ZC, Engel DLJ, Simon CC, Negherbon KR, Murphy LJ, Tamavimok W, Anderson GM, Janušonis S. Brain growth trajectories in mouse strains with central and peripheral serotonin differences: relevance to autism models. Neuroscience 2012; 210:286-95. [PMID: 22450231 DOI: 10.1016/j.neuroscience.2012.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 03/01/2012] [Accepted: 03/03/2012] [Indexed: 10/28/2022]
Abstract
The genetic heterogeneity of autism spectrum disorders (ASDs) suggests that their underlying neurobiology involves dysfunction at the neural network level. Understanding these neural networks will require a major collaborative effort and will depend on validated and widely accepted animal models. Many mouse models have been proposed in autism research, but the assessment of their validity often has been limited to measuring social interactions. However, two other well-replicated findings have been reported in ASDs: transient brain overgrowth in early postnatal life and elevated 5-HT (serotonin) levels in blood platelets (platelet hyperserotonemia). We examined two inbred mouse strains (C57BL/6 and BALB/c) with respect to these phenomena. The BALB/c strain is less social and exhibits some other autistic-like behaviors. In addition, it has a lower 5-HT synthesis rate in the central nervous system due to a single-nucleotide polymorphism in the tryptophan hydroxylase 2 (Tph2) gene. The postnatal growth of brain mass was analyzed with mixed-effects models that included litter effects. The volume of the hippocampal complex and the thickness of the somatosensory cortex were measured in 3D-brain reconstructions from serial sections. The postnatal whole-blood 5-HT levels were assessed with high-performance liquid chromatography. With respect to the BALB/c strain, the C57BL/6 strain showed transient brain overgrowth and persistent blood hyperserotonemia. The hippocampal volume was permanently enlarged in the C57BL/6 strain, with no change in the adult brain mass. These results indicate that, in mice, autistic-like shifts in the brain and periphery may be associated with less autistic-like behaviors. Importantly, they suggest that consistency among behavioral, anatomical, and physiological measures may expedite the validation of new and previously proposed mouse models of autism, and that the construct validity of models should be demonstrated when these measures are inconsistent.
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Affiliation(s)
- Z C Flood
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA
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418
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Meyza KZ, Blanchard DC, Pearson BL, Pobbe RL, Blanchard RJ. Fractone-associated N-sulfated heparan sulfate shows reduced quantity in BTBR T+tf/J mice: a strong model of autism. Behav Brain Res 2012; 228:247-53. [PMID: 22101175 PMCID: PMC3268836 DOI: 10.1016/j.bbr.2011.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 11/01/2011] [Accepted: 11/03/2011] [Indexed: 12/20/2022]
Abstract
BTBR T+tf/J (BTBR) mice show abnormal social, communicatory, and repetitive/stereotyped behaviors paralleling many of the symptoms of autism spectrum disorders. BTBR also show agenesis of the corpus callosum (CC) suggesting major perturbations of growth or guidance factors in the dorsal forebrain [1]. Heparan sulfate (HS) is a polysaccaride found in the brain and other animal tissues. It binds to a wide variety of ligands and through these ligands modulates a number of biological processes, including cell proliferation and differentiation, migration and guidance. It is aggregated on fractal-like structures (fractones) in the subventricular zone (SVZ), that may be visualized by laminin immunoreactivity (LAM-ir), as well as by HS immunoreactivity (HS-ir). We report that the lateral ventricles of BTBR mice were drastically reduced in area compared to C57BL/6J (B6) mice while the BTBR SVZ was significantly shorter than that of B6. In addition to much smaller fractones for BTBR, both HS and LAM-ir associated with fractones were significantly reduced in BTBR, and their anterior-posterior distributions were also altered. Finally, the ratio of HS to LAM in individual fractones was significantly higher in BTBR than in B6 mice. These data, in agreement with other findings linking HS to callosal development, suggest that variations in the quantity and distribution of HS in the SVZ of the lateral ventricles may be important modulators of the brain structural abnormalities of BTBR mice, and, potentially, contribute to the behavioral pathologies of these animals.
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Affiliation(s)
- Ksenia Z. Meyza
- Pacific Biosciences Research Center, University of Hawaii, 1993 East-West Road, Honolulu, HI 96822, USA
| | - D. Caroline Blanchard
- Pacific Biosciences Research Center, University of Hawaii, 1993 East-West Road, Honolulu, HI 96822, USA
| | - Brandon L. Pearson
- Department of Psychology, University of Hawaii, 2430 Campus Road, Honolulu, HI 96822, USA
| | - Roger L.H. Pobbe
- Pacific Biosciences Research Center, University of Hawaii, 1993 East-West Road, Honolulu, HI 96822, USA
| | - Robert J. Blanchard
- Department of Psychology, University of Hawaii, 2430 Campus Road, Honolulu, HI 96822, USA
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419
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Cheng Y, Thomas A, Mardini F, Bianchi SL, Tang JX, Peng J, Wei H, Eckenhoff MF, Eckenhoff RG, Levy RJ. Neurodevelopmental consequences of sub-clinical carbon monoxide exposure in newborn mice. PLoS One 2012; 7:e32029. [PMID: 22348142 PMCID: PMC3277503 DOI: 10.1371/journal.pone.0032029] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 01/18/2012] [Indexed: 12/13/2022] Open
Abstract
Carbon monoxide (CO) exposure at high concentrations results in overt neurotoxicity. Exposure to low CO concentrations occurs commonly yet is usually sub-clinical. Infants are uniquely vulnerable to a variety of toxins, however, the effects of postnatal sub-clinical CO exposure on the developing brain are unknown. Apoptosis occurs normally within the brain during development and is critical for synaptogenesis. Here we demonstrate that brief, postnatal sub-clinical CO exposure inhibits developmental neuroapoptosis resulting in impaired learning, memory, and social behavior. Three hour exposure to 5 ppm or 100 ppm CO impaired cytochrome c release, caspase-3 activation, and apoptosis in neocortex and hippocampus of 10 day old CD-1 mice. CO increased NeuN protein, neuronal numbers, and resulted in megalencephaly. CO-exposed mice demonstrated impaired memory and learning and reduced socialization following exposure. Thus, CO-mediated inhibition of neuroapoptosis might represent an important etiology of acquired neurocognitive impairment and behavioral disorders in children.
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Affiliation(s)
- Ying Cheng
- Division of Anesthesiology and Pain Medicine, Children's National Medical Center, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
| | - Adia Thomas
- Division of Anesthesiology and Pain Medicine, Children's National Medical Center, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
| | - Feras Mardini
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Shannon L. Bianchi
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Junxia X. Tang
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jun Peng
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Huafeng Wei
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Maryellen F. Eckenhoff
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Roderic G. Eckenhoff
- Department of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Richard J. Levy
- Division of Anesthesiology and Pain Medicine, Children's National Medical Center, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
- * E-mail:
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420
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Abstract
Autism (autism spectrum disorders) is a complex, strongly genetically influenced, behaviorally defined disorder of the immature brain associated with very uneven intellectual abilities. Among its most salient and potentially treatable neurologic features that this article focuses on are epilepsy, disorganized sleep patterns, and sensory and motor deficits. Its many causes and wide range of severity means that there is no symptom, no pathology, imaging, electroencephalography, or other biologic feature, and no biologic treatment that is universal or diagnostic of this developmental syndrome.
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Affiliation(s)
- Wendy G Silver
- Saul R Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA.
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421
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de Sousa A, Cunha E. Hominins and the emergence of the modern human brain. PROGRESS IN BRAIN RESEARCH 2012; 195:293-322. [DOI: 10.1016/b978-0-444-53860-4.00014-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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422
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Ellegood J, Henkelman RM, Lerch JP. Neuroanatomical Assessment of the Integrin β3 Mouse Model Related to Autism and the Serotonin System Using High Resolution MRI. Front Psychiatry 2012; 3:37. [PMID: 22557981 PMCID: PMC3337465 DOI: 10.3389/fpsyt.2012.00037] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/09/2012] [Indexed: 12/02/2022] Open
Abstract
The integrinβ3 (ITGβ3) gene has been associated with both autism and the serotonin system. The purpose of this study was to examine the volumetric differences in the brain of an ITGβ3 homozygous knockout mouse model compared with a corresponding wild-type mouse using high resolution magnetic resonance imaging and detailed statistical analyses. The most striking difference found was an 11% reduction in total brain volume. Moreover, 32 different regions were found to have significantly different relative volumes (percentage total brain volume) in the ITGβ3 mouse. A number of interesting differences relevant to autism were discovered including a smaller corpus callosum volume and bilateral decreases in the hippocampus, striatum, and cerebellum. Relative volume increases were also found in the frontal and parieto-temporal lobes as well as in the amygdala. Particularly intriguing were the changes in the lateral wings of the dorsal raphe nuclei since that nucleus is so integral to the development of many different brain regions and the serotonin system in general.
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Affiliation(s)
- Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children Toronto, ON, Canada
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423
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Charvet CJ, Finlay BL. Embracing covariation in brain evolution: large brains, extended development, and flexible primate social systems. PROGRESS IN BRAIN RESEARCH 2012; 195:71-87. [PMID: 22230623 PMCID: PMC3327164 DOI: 10.1016/b978-0-444-53860-4.00004-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Brain size, body size, developmental length, life span, costs of raising offspring, behavioral complexity, and social structures are correlated in mammals due to intrinsic life-history requirements. Dissecting variation and direction of causation in this web of relationships often draw attention away from the factors that correlate with basic life parameters. We consider the "social brain hypothesis," which postulates that overall brain and the isocortex are selectively enlarged to confer social abilities in primates, as an example of this enterprise and pitfalls. We consider patterns of brain scaling, modularity, flexibility of brain organization, the "leverage," and direction of selection on proposed dimensions. We conclude that the evidence supporting selective changes in isocortex or brain size for the isolated ability to manage social relationships is poor. Strong covariation in size and developmental duration coupled with flexible brains allow organisms to adapt in variable social and ecological environments across the life span and in evolution.
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Affiliation(s)
- Christine J Charvet
- Behavioral and Evolutionary Neuroscience Group, Department of Psychology, Cornell University, Ithaca NY, USA.
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424
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Veenstra-VanderWeele J, Blakely RD. Networking in autism: leveraging genetic, biomarker and model system findings in the search for new treatments. Neuropsychopharmacology 2012; 37:196-212. [PMID: 21937981 PMCID: PMC3238072 DOI: 10.1038/npp.2011.185] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/05/2011] [Accepted: 08/06/2011] [Indexed: 12/20/2022]
Abstract
Autism Spectrum Disorder (ASD) is a common neurodevelopmental disorder affecting approximately 1% of children. ASD is defined by core symptoms in two domains: negative symptoms of impairment in social and communication function, and positive symptoms of restricted and repetitive behaviors. Available treatments are inadequate for treating both core symptoms and associated conditions. Twin studies indicate that ASD susceptibility has a large heritable component. Genetic studies have identified promising leads, with converging insights emerging from single-gene disorders that bear ASD features, with particular interest in mammalian target of rapamycin (mTOR)-linked synaptic plasticity mechanisms. Mouse models of these disorders are revealing not only opportunities to model behavioral perturbations across species, but also evidence of postnatal rescue of brain and behavioral phenotypes. An intense search for ASD biomarkers has consistently pointed to elevated platelet serotonin (5-HT) levels and a surge in brain growth in the first 2 years of life. Following a review of the diversity of ASD phenotypes and its genetic origins and biomarkers, we discuss opportunities for translation of these findings into novel ASD treatments, focusing on mTor- and 5-HT-signaling pathways, and their possible intersection. Paralleling the progress made in understanding the root causes of rare genetic syndromes that affect cognitive development, we anticipate progress in models systems using bona fide ASD-associated molecular changes that have the potential to accelerate the development of ASD diagnostics and therapeutics.
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Affiliation(s)
- Jeremy Veenstra-VanderWeele
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Center for Molecular Neuroscience, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Randy D Blakely
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Center for Molecular Neuroscience, Vanderbilt University School of Medicine, Nashville, TN, USA
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425
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426
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van Soelen ILC, Brouwer RM, van Baal GCM, Schnack HG, Peper JS, Chen L, Kahn RS, Boomsma DI, Hulshoff Pol HE. Heritability of volumetric brain changes and height in children entering puberty. Hum Brain Mapp 2011; 34:713-25. [PMID: 22140022 DOI: 10.1002/hbm.21468] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 08/08/2011] [Accepted: 08/24/2011] [Indexed: 12/22/2022] Open
Abstract
The human brain undergoes structural changes in children entering puberty, while simultaneously children increase in height. It is not known if brain changes are under genetic control, and whether they are related to genetic factors influencing the amount of overall increase in height. Twins underwent magnetic resonance imaging brain scans at age 9 (N = 190) and 12 (N = 125). High heritability estimates were found at both ages for height and brain volumes (49-96%), and high genetic correlation between ages were observed (r(g) > 0.89). With increasing age, whole brain (+1.1%), cerebellum (+4.2%), cerebral white matter (+5.1%), and lateral ventricle (+9.4%) volumes increased, and third ventricle (-4.0%) and cerebral gray matter (-1.6%) volumes decreased. Children increased on average 13.8 cm in height (9.9%). Genetic influences on individual difference in volumetric brain and height changes were estimated, both within and across traits. The same genetic factors influenced both cerebral (20% heritable) and cerebellar volumetric changes (45%). Thus, the extent to which changes in cerebral and cerebellar volumes are heritable in children entering puberty are due to the same genes that influence change in both structures. The increase in height was heritable (73%), and not associated with cerebral volumetric change, but positively associated with cerebellar volume change (r(p) = 0.24). This association was explained by a genetic correlation (r(g) = 0.48) between height and cerebellar change. Brain and body each expand at their own pace and through separate genetic pathways. There are distinct genetic processes acting on structural brain development, which cannot be explained by genetic increase in height.
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Affiliation(s)
- Inge L C van Soelen
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.
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427
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Duerden EG, Mak-Fan KM, Taylor MJ, Roberts SW. Regional differences in grey and white matter in children and adults with autism spectrum disorders: an activation likelihood estimate (ALE) meta-analysis. Autism Res 2011; 5:49-66. [PMID: 22139976 DOI: 10.1002/aur.235] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 09/19/2011] [Accepted: 10/20/2011] [Indexed: 01/08/2023]
Abstract
Structural alterations in brain morphology have been inconsistently reported in children compared to adults with autism spectrum disorder (ASD). We assessed these differences by performing meta-analysis on the data from 19 voxel-based morphometry studies. Common findings across the age groups were grey matter reduction in left putamen and medial prefrontal cortex (mPFC) and grey matter increases in the lateral PFC, while white matter decreases were seen mainly in the children in frontostriatal pathways. In the ASD sample, children/adolescents were more likely than adults to have increased grey matter in bilateral fusiform gyrus, right cingulate and insula. Results show that clear maturational differences exist in social cognition and limbic processing regions only in children/adolescents and not in adults with ASD, and may underlie the emotional regulation that improves with age in this population.
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Affiliation(s)
- Emma G Duerden
- Autism Research Unit, The Hospital for Sick Children, Toronto, Ontario, Canada.
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428
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Tobiasova Z, van der Lingen KHB, Scahill L, Leckman JF, Zhang Y, Chae W, McCracken JT, McDougle CJ, Vitiello B, Tierney E, Aman MG, Arnold LE, Katsovich L, Hoekstra PJ, Volkmar F, Bothwell ALM, Kawikova I. Risperidone-related improvement of irritability in children with autism is not associated with changes in serum of epidermal growth factor and interleukin-13. J Child Adolesc Psychopharmacol 2011; 21:555-64. [PMID: 22070180 PMCID: PMC3279715 DOI: 10.1089/cap.2010.0134] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Risperidone has been shown to improve serious behavioral problems in children with autism. Here we asked whether risperidone-associated improvement was related to changes in concentrations of inflammatory molecules in the serum of these subjects. Seven molecules were identified as worthy of further assessment by performing a pilot analysis of 31 inflammatory markers in 21 medication-free subjects with autism versus 15 healthy controls: epidermal growth factor (EGF), interferon-γ (IFN-γ), interleukin (IL)-13, IL-17, monocyte chemoattractant protein-1 (MCP-1), IL-1 and IL-1-receptor antagonist. Serum concentrations of these markers were then established in a different set of subjects that participated in a double-blind, clinical trial and an expanded group of healthy subjects. In the first analysis, samples obtained from subjects with autism at baseline visits were compared to visits after 8-week treatment with placebo (n=37) or risperidone (n=40). The cytokine concentrations remained stable over the 8-week period for both risperidone and placebo groups. In the second analysis, we explored further the differences between medication-free subjects with autism (n=77) and healthy controls (recruited independently; n=19). Serum levels of EGF were elevated in subjects with autism (median=103 pg/mL, n=75) in comparison to healthy controls (75 pg/mL, n=19; p<0.05), and levels of IL-13 were decreased in autism (median=0.8 pg/mL, n=77) in comparison to controls (9.8 pg/mL, n=19; p=0.0003). These changes did not correlate with standardized measures used for a diagnosis of autism. In summary, risperidone-induced clinical improvement in subjects with autism was not associated with changes in the serum inflammatory markers measured. Whether altered levels of EGF and IL-13 play a role in the pathogenesis or phenotype of autism requires further investigation.
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Affiliation(s)
- Zuzana Tobiasova
- Authors with equal contribution
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Klaas H. B. van der Lingen
- Authors with equal contribution
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
- Child Study Center of Yale University School of Medicine, New Haven, CT
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Netherlands
| | - Lawrence Scahill
- Authors with equal contribution
- Yale University School of Nursing, New Haven, CT
| | - James F. Leckman
- Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Yan Zhang
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Wookjin Chae
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
| | - James T. McCracken
- Division of Child and Adolescent Psychiatry, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | | | | | - Elaine Tierney
- Department of Psychiatry, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | | | - Liliya Katsovich
- Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Pieter J. Hoekstra
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Netherlands
| | - Fred Volkmar
- Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Alfred L. M. Bothwell
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
| | - Ivana Kawikova
- Department of Immunobiology, Child Study Center of Yale University School of Medicine, New Haven, CT
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429
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Janušonis S. Relationships among variables and their equilibrium values: caveats of time-less interpretation. Biol Rev Camb Philos Soc 2011; 87:275-89. [DOI: 10.1111/j.1469-185x.2011.00194.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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430
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Scheel C, Rotarska-Jagiela A, Schilbach L, Lehnhardt FG, Krug B, Vogeley K, Tepest R. Imaging derived cortical thickness reduction in high-functioning autism: key regions and temporal slope. Neuroimage 2011; 58:391-400. [PMID: 21749926 DOI: 10.1016/j.neuroimage.2011.06.040] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/31/2011] [Accepted: 06/16/2011] [Indexed: 11/16/2022] Open
Abstract
Cortical thickness (CT) changes possibly contribute to the complex symptomatology of autism. The aberrant developmental trajectories underlying such differences in certain brain regions and their continuation in adulthood are a matter of intense debate. We studied 28 adults with high-functioning autism (HFA) and 28 control subjects matched for age, gender, IQ and handedness. A surface-based whole brain analysis utilizing FreeSurfer was employed to detect CT differences between the two diagnostic groups and to investigate the time course of age-related changes. Direct comparison with control subjects revealed thinner cortex in HFA in the posterior superior temporal sulcus (pSTS) of the left hemisphere. Considering the time course of CT development we found clusters around the pSTS and cuneus in the left and the paracentral lobule in the right hemisphere to be thinner in HFA with comparable age-related slopes in patients and controls. Conversely, we found clusters around the supramarginal gyrus and inferior parietal lobule (IPL) in the left and the precentral and postcentral gyrus in the right hemisphere to be thinner in HFA, but with different age-related slopes in patients and controls. In the latter regions CT showed a steady decrease in controls but no analogous thinning in HFA. CT analyses contribute in characterizing neuroanatomical correlates of HFA. Reduced CT is present in brain regions involved in social cognition. Furthermore, our results demonstrate that aberrant brain development leading to such differences is proceeding throughout adulthood. Discrepancies in prior morphometric studies may be induced by the complex time course of cortical changes.
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Affiliation(s)
- Christian Scheel
- Department of Psychiatry and Psychotherapy, University Hospital of Cologne, Kerpener Str. 62, 50924 Cologne, Germany
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Baron-Cohen S, Lombardo MV, Auyeung B, Ashwin E, Chakrabarti B, Knickmeyer R. Why are autism spectrum conditions more prevalent in males? PLoS Biol 2011; 9:e1001081. [PMID: 21695109 PMCID: PMC3114757 DOI: 10.1371/journal.pbio.1001081] [Citation(s) in RCA: 435] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Autism Spectrum Conditions (ASC) are much more common in males, a bias that may offer clues to the etiology of this condition. Although the cause of this bias remains a mystery, we argue that it occurs because ASC is an extreme manifestation of the male brain. The extreme male brain (EMB) theory, first proposed in 1997, is an extension of the Empathizing-Systemizing (E-S) theory of typical sex differences that proposes that females on average have a stronger drive to empathize while males on average have a stronger drive to systemize. In this first major update since 2005, we describe some of the evidence relating to the EMB theory of ASC and consider how typical sex differences in brain structure may be relevant to ASC. One possible biological mechanism to account for the male bias is the effect of fetal testosterone (fT). We also consider alternative biological theories, the X and Y chromosome theories, and the reduced autosomal penetrance theory. None of these theories has yet been fully confirmed or refuted, though the weight of evidence in favor of the fT theory is growing from converging sources (longitudinal amniocentesis studies from pregnancy to age 10 years old, current hormone studies, and genetic association studies of SNPs in the sex steroid pathways). Ultimately, as these theories are not mutually exclusive and ASC is multi-factorial, they may help explain the male prevalence of ASC.
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Affiliation(s)
- Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
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