1
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Grissom NM, Glewwe N, Chen C, Giglio E. Sex mechanisms as nonbinary influences on cognitive diversity. Horm Behav 2024; 162:105544. [PMID: 38643533 DOI: 10.1016/j.yhbeh.2024.105544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/23/2024]
Abstract
Essentially all neuropsychiatric diagnoses show some degree of sex and/or gender differences in their etiology, diagnosis, or prognosis. As a result, the roles of sex-related variables in behavior and cognition are of strong interest to many, with several lines of research showing effects on executive functions and value-based decision making in particular. These findings are often framed within a sex binary, with behavior of females described as less optimal than male "defaults"-- a framing that pits males and females against each other and deemphasizes the enormous overlap in fundamental neural mechanisms across sexes. Here, we propose an alternative framework in which sex-related factors encompass just one subset of many sources of valuable diversity in cognition. First, we review literature establishing multidimensional, nonbinary impacts of factors related to sex chromosomes and endocrine mechanisms on cognition, focusing on value- based decision-making tasks. Next, we present two suggestions for nonbinary interpretations and analyses of sex-related data that can be implemented by behavioral neuroscientists without devoting laboratory resources to delving into mechanisms underlying sex differences. We recommend (1) shifting interpretations of behavior away from performance metrics and towards strategy assessments to avoid the fallacy that the performance of one sex is worse than another; and (2) asking how much variance sex explains in measures and whether any differences are mosaic rather than binary, to avoid assuming that sex differences in separate measures are inextricably correlated. Nonbinary frameworks in research on cognition will allow neuroscience to represent the full spectrum of brains and behaviors.
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Affiliation(s)
- Nicola M Grissom
- Department of Psychology, University of Minnesota, United States of America.
| | - Nic Glewwe
- Department of Psychology, University of Minnesota, United States of America
| | - Cathy Chen
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, United States of America
| | - Erin Giglio
- Department of Psychology, University of Minnesota, United States of America
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2
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Martínez-Tazo P, Santos A, Selim MK, Espinós-Soler E, De Santis S. Sex matters: The MouseX DW-ALLEN Atlas for mice diffusion-weighted MR imaging. Neuroimage 2024; 292:120573. [PMID: 38521211 DOI: 10.1016/j.neuroimage.2024.120573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/25/2024] Open
Abstract
Overcoming sex bias in preclinical research requires not only including animals of both sexes in the experiments, but also developing proper tools to handle such data. Recent work revealed sensitivity of diffusion-weighted MRI to glia morphological changes in response to inflammatory stimuli, opening up exciting possibilities to characterize inflammation in a variety of preclinical models of pathologies, the great majority of them available in mice. However, there are limited resources dedicated to mouse imaging, like those required for the data processing and analysis. To fill this gap, we build a mouse MRI template of both structural and diffusion contrasts, with anatomical annotation according to the Allen Mouse Brain Atlas, the most detailed public resource for mouse brain investigation. To achieve a standardized resource, we use a large cohort of animals in vivo, and include animals of both sexes. To prove the utility of this resource to integrate imaging and molecular data, we demonstrate significant association between the mean diffusivity from MRI and gene expression-based glia density. To demonstrate the need of equitable sex representation, we compared across sexes the warp fields needed to match a male-based template, and our template built with both sexes. Then, we use both templates for analysing mice imaging data obtained in animals of different ages, demonstrating that using a male-based template creates spurious significant sex effects, not present otherwise. All in all, our MouseX DW-ALLEN Atlas will be a widely useful resource getting us one step closer to equitable healthcare.
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Affiliation(s)
| | - Alexandra Santos
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Mohamed Kotb Selim
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Elena Espinós-Soler
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain.
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3
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Guma E, Beauchamp A, Liu S, Levitis E, Ellegood J, Pham L, Mars RB, Raznahan A, Lerch JP. Comparative neuroimaging of sex differences in human and mouse brain anatomy. eLife 2024; 13:RP92200. [PMID: 38488854 PMCID: PMC10942785 DOI: 10.7554/elife.92200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024] Open
Abstract
In vivo neuroimaging studies have established several reproducible volumetric sex differences in the human brain, but the causes of such differences are hard to parse. While mouse models are useful for understanding the cellular and mechanistic bases of sex-specific brain development, there have been no attempts to formally compare human and mouse neuroanatomical sex differences to ascertain how well they translate. Addressing this question would shed critical light on the use of the mouse as a translational model for sex differences in the human brain and provide insights into the degree to which sex differences in brain volume are conserved across mammals. Here, we use structural magnetic resonance imaging to conduct the first comparative neuroimaging study of sex-specific neuroanatomy of the human and mouse brain. In line with previous findings, we observe that in humans, males have significantly larger and more variable total brain volume; these sex differences are not mirrored in mice. After controlling for total brain volume, we observe modest cross-species congruence in the volumetric effect size of sex across 60 homologous regions (r=0.30). This cross-species congruence is greater in the cortex (r=0.33) than non-cortex (r=0.16). By incorporating regional measures of gene expression in both species, we reveal that cortical regions with greater cross-species congruence in volumetric sex differences also show greater cross-species congruence in the expression profile of 2835 homologous genes. This phenomenon differentiates primary sensory regions with high congruence of sex effects and gene expression from limbic cortices where congruence in both these features was weaker between species. These findings help identify aspects of sex-biased brain anatomy present in mice that are retained, lost, or inverted in humans. More broadly, our work provides an empirical basis for targeting mechanistic studies of sex-specific brain development in mice to brain regions that best echo sex-specific brain development in humans.
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Affiliation(s)
- Elisa Guma
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental HealthBethesdaUnited States
| | - Antoine Beauchamp
- Mouse Imaging CentreTorontoCanada
- The Hospital for Sick ChildrenTorontoCanada
- Department of Medical Biophysics, University of TorontoTorontoCanada
| | - Siyuan Liu
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental HealthBethesdaUnited States
| | - Elizabeth Levitis
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental HealthBethesdaUnited States
| | - Jacob Ellegood
- Mouse Imaging CentreTorontoCanada
- The Hospital for Sick ChildrenTorontoCanada
| | - Linh Pham
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental HealthBethesdaUnited States
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical 15 Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Rogier B Mars
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical 15 Neurosciences, University of OxfordOxfordUnited Kingdom
- Donders Institute for Brain, Cognition and Behaviour, Radboud University NijmegenNijmegenNetherlands
| | - Armin Raznahan
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental HealthBethesdaUnited States
| | - Jason P Lerch
- Mouse Imaging CentreTorontoCanada
- The Hospital for Sick ChildrenTorontoCanada
- Department of Medical Biophysics, University of TorontoTorontoCanada
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical 15 Neurosciences, University of OxfordOxfordUnited Kingdom
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4
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Szulc-Lerch K, Yeung J, de Guzman AE, Egan S, Yee Y, Fernandes D, Lerch JP, Mabbott DJ, Nieman BJ. Exercise promotes growth and rescues volume deficits in the hippocampus after cranial radiation in young mice. NMR IN BIOMEDICINE 2023; 36:e5015. [PMID: 37548099 DOI: 10.1002/nbm.5015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 08/08/2023]
Abstract
Human and animal studies suggest that exercise promotes healthy brain development and function, including promoting hippocampal growth. Childhood cancer survivors that have received cranial radiotherapy exhibit hippocampal volume deficits and are at risk of impaired cognitive function, thus they may benefit from regular exercise. While morphological changes induced by exercise have been characterized using magnetic resonance imaging (MRI) in humans and animal models, evaluation of changes across the brain through development and following cranial radiation is lacking. In this study, we used high-resolution longitudinal MRI through development to evaluate the effects of exercise in a pediatric mouse model of cranial radiation. Female mice received whole-brain radiation (7 Gy) or sham radiation (0 Gy) at an infant equivalent age (P16). One week after irradiation, mice were housed in either a regular cage or a cage equipped with a running wheel. In vivo MRI was performed prior to irradiation, and at three subsequent timepoints to evaluate the effects of radiation and exercise. We used a linear mixed-effects model to assess volumetric and cortical thickness changes. Exercise caused substantial increases in the volumes of certain brain regions, notably the hippocampus in both irradiated and nonirradiated mice. Volume increases exceeded the deficits induced by cranial irradiation. The effect of exercise and irradiation on subregional hippocampal volumes was also characterized. In addition, we characterized cortical thickness changes across development and found that it peaked between P23 and P43, depending on the region. Exercise also induced regional alterations in cortical thickness after 3 weeks of voluntary exercise, while irradiation did not substantially alter cortical thickness. Our results show that exercise has the potential to alter neuroanatomical outcomes in both irradiated and nonirradiated mice. This supports ongoing research exploring exercise as a strategy for improving neurocognitive development for children, particularly those treated with cranial radiotherapy.
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Affiliation(s)
- Kamila Szulc-Lerch
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
| | - Jonas Yeung
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - A Elizabeth de Guzman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Functional Neuroimaging Laboratory, Istituto Italiano di Tecnologia, Rovereto, Italy
| | - Shannon Egan
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - Yohan Yee
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Darren Fernandes
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Jason P Lerch
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Donald J Mabbott
- Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
- Department of Psychology, Hospital for Sick Children, Toronto, Canada
| | - Brian J Nieman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Ontario Institute for Cancer Research, Toronto, Canada
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5
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Guma E, Beauchamp A, Liu S, Levitis E, Ellegood J, Pham L, Mars RB, Raznahan A, Lerch JP. Comparative neuroimaging of sex differences in human and mouse brain anatomy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.23.554334. [PMID: 37662398 PMCID: PMC10473765 DOI: 10.1101/2023.08.23.554334] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
In vivo neuroimaging studies have established several reproducible volumetric sex differences in the human brain, but the causes of such differences are hard to parse. While mouse models are useful for understanding the cellular and mechanistic bases of sex-biased brain development in mammals, there have been no attempts to formally compare mouse and human sex differences across the whole brain to ascertain how well they translate. Addressing this question would shed critical light on use of the mouse as a translational model for sex differences in the human brain and provide insights into the degree to which sex differences in brain volume are conserved across mammals. Here, we use cross-species structural magnetic resonance imaging to carry out the first comparative neuroimaging study of sex-biased neuroanatomical organization of the human and mouse brain. In line with previous findings, we observe that in humans, males have significantly larger and more variable total brain volume; these sex differences are not mirrored in mice. After controlling for total brain volume, we observe modest cross-species congruence in the volumetric effect size of sex across 60 homologous brain regions (r=0.30; e.g.: M>F amygdala, hippocampus, bed nucleus of the stria terminalis, and hypothalamus and F>M anterior cingulate, somatosensory, and primary auditory cortices). This cross-species congruence is greater in the cortex (r=0.33) than non-cortex (r=0.16). By incorporating regional measures of gene expression in both species, we reveal that cortical regions with greater cross-species congruence in volumetric sex differences also show greater cross-species congruence in the expression profile of 2835 homologous genes. This phenomenon differentiates primary sensory regions with high congruence of sex effects and gene expression from limbic cortices where congruence in both these features was weaker between species. These findings help identify aspects of sex-biased brain anatomy present in mice that are retained, lost, or inverted in humans. More broadly, our work provides an empirical basis for targeting mechanistic studies of sex-biased brain development in mice to brain regions that best echo sex-biased brain development in humans.
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Affiliation(s)
- Elisa Guma
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Antoine Beauchamp
- Mouse Imaging Centre, Toronto, Ontario, Canada
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Siyuan Liu
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Elizabeth Levitis
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Jacob Ellegood
- Mouse Imaging Centre, Toronto, Ontario, Canada
- The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Linh Pham
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, USA
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Rogier B Mars
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Armin Raznahan
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Jason P Lerch
- Mouse Imaging Centre, Toronto, Ontario, Canada
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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6
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Shafee R, Moraczewski D, Liu S, Mallard T, Thomas A, Raznahan A. A sex-stratified analysis of the genetic architecture of human brain anatomy. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.09.23293881. [PMID: 37609186 PMCID: PMC10441503 DOI: 10.1101/2023.08.09.23293881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Large biobanks have dramatically advanced our understanding of genetic influences on human brain anatomy. However, most studies have combined rather than compared males and females - despite theoretical grounds for potential sex differences. By systematically screening for sex differences in the common genetic architecture of > 1000 neuroanatomical phenotypes in the UK Biobank, we establish a general concordance between males and females in heritability estimates, genetic correlations and variant-level effects. Notable exceptions include: higher mean h 2 in females for regional volume and surface area phenotypes; between-sex genetic correlations that are significantly below 1 in the insula and parietal cortex; and, a male-specific effect common variant mapping to RBFOX1 - a gene linked to multiple male-biased neuropsychiatric disorders. This work suggests that common variant influences on human brain anatomy are largely consistent between males and females, with a few exceptions that will guide future research as biobanks continue to grow in size.
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7
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Reale C, Invernizzi F, Panteghini C, Garavaglia B. Genetics, sex, and gender. J Neurosci Res 2023; 101:553-562. [PMID: 34498752 DOI: 10.1002/jnr.24945] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/05/2021] [Indexed: 12/27/2022]
Abstract
This review aims to give an overview of what has been discovered so far and what still needs to be analyzed about how sex and gender affect the disease development. These two terms are often confused and indifferently used. In principle, the term "sex" refers to biological differences between males and females, specifically reproductive organs and their functions, while the term "gender" refers to the social context in which people live and which contributes to a subjective sexual identity, masculine or feminine. This dichotomy, however, is not so rigid and both sex and gender influence different aspects of human health, such as brain, health and aging and drug treatment and pharmacokinetics. In particular, we want to focus on genetic differences between men and women: indeed, the expression of the genes mapped on X chromosome or Y chromosome and all epigenetic interactions affect the diseases development. Finally, we will briefly outline sex and gender differences in clinical manifestations of three neurological diseases: Alzheimer's disease, Parkinson's disease, and obsessive compulsive disorder. In the era of personalized medicine, we must not forget the importance of gender medicine to promote personalized care for any kind of patients.
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Affiliation(s)
- Chiara Reale
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS, Istituto Neurologico "C. Besta", Milan, Italy
| | - Federica Invernizzi
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS, Istituto Neurologico "C. Besta", Milan, Italy
| | - Celeste Panteghini
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS, Istituto Neurologico "C. Besta", Milan, Italy
| | - Barbara Garavaglia
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS, Istituto Neurologico "C. Besta", Milan, Italy
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Guma E, Beauchamp A, Liu S, Levitis E, Clasen LS, Torres E, Blumenthal J, Lalonde F, Qiu LR, Hrncir H, MacKenzie-Graham A, Yang X, Arnold AP, Lerch JP, Raznahan A. A Cross-Species Neuroimaging Study of Sex Chromosome Dosage Effects on Human and Mouse Brain Anatomy. J Neurosci 2023; 43:1321-1333. [PMID: 36631267 PMCID: PMC9987571 DOI: 10.1523/jneurosci.1761-22.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 01/13/2023] Open
Abstract
All eutherian mammals show chromosomal sex determination with contrasting sex chromosome dosages (SCDs) between males (XY) and females (XX). Studies in transgenic mice and humans with sex chromosome trisomy (SCT) have revealed direct SCD effects on regional mammalian brain anatomy, but we lack a formal test for cross-species conservation of these effects. Here, we develop a harmonized framework for comparative structural neuroimaging and apply this to systematically profile SCD effects on regional brain anatomy in both humans and mice by contrasting groups with SCT (XXY and XYY) versus XY controls. Total brain size was substantially altered by SCT in humans (significantly decreased by XXY and increased by XYY), but not in mice. Robust and spatially convergent effects of XXY and XYY on regional brain volume were observed in humans, but not mice, when controlling for global volume differences. However, mice do show subtle effects of XXY and XYY on regional volume, although there is not a general spatial convergence in these effects within mice or between species. Notwithstanding this general lack of conservation in SCT effects, we detect several brain regions that show overlapping effects of XXY and XYY both within and between species (cerebellar, parietal, and orbitofrontal cortex), thereby nominating high priority targets for future translational dissection of SCD effects on the mammalian brain. Our study introduces a generalizable framework for comparative neuroimaging in humans and mice and applies this to achieve a cross-species comparison of SCD effects on the mammalian brain through the lens of SCT.SIGNIFICANCE STATEMENT Sex chromosome dosage (SCD) affects neuroanatomy and risk for psychopathology in humans. Performing mechanistic studies in the human brain is challenging but possible in mouse models. Here, we develop a framework for cross-species neuroimaging analysis and use this to show that an added X- or Y-chromosome significantly alters human brain anatomy but has muted effects in the mouse brain. However, we do find evidence for conserved cross-species impact of an added chromosome in the fronto-parietal cortices and cerebellum, which point to regions for future mechanistic dissection of sex chromosome dosage effects on brain development.
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Affiliation(s)
- Elisa Guma
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Antoine Beauchamp
- Mouse Imaging Centre, Toronto, Ontario M5T 3H7, Canada
- The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Siyuan Liu
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Elizabeth Levitis
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Liv S. Clasen
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Erin Torres
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Jonathan Blumenthal
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Francois Lalonde
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
| | - Lily R. Qiu
- Mouse Imaging Centre, Toronto, Ontario M5T 3H7, Canada
- The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Haley Hrncir
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095
| | - Allan MacKenzie-Graham
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095
| | - Arthur P. Arnold
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095
| | - Jason P. Lerch
- Mouse Imaging Centre, Toronto, Ontario M5T 3H7, Canada
- The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, OX3 9DU, United Kingdom
| | - Armin Raznahan
- Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, Bethesda, 20892, Maryland
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9
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Moruno-Manchon J, Noh B, McCullough L. Sex-biased autophagy as a potential mechanism mediating sex differences in ischemic stroke outcome. Neural Regen Res 2023; 18:31-37. [PMID: 35799505 PMCID: PMC9241419 DOI: 10.4103/1673-5374.340406] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Stroke is the second leading cause of death and a major cause of disability worldwide, and biological sex is an important determining factor in stroke incidence and pathology. From childhood through adulthood, men have a higher incidence of stroke compared with women. Abundant research has confirmed the beneficial effects of estrogen in experimental ischemic stroke but genetic factors such as the X-chromosome complement can also play an important role in determining sex differences in stroke. Autophagy is a self-degrading cellular process orchestrated by multiple core proteins, which leads to the engulfment of cytoplasmic material and degradation of cargo after autophagy vesicles fuse with lysosomes or endosomes. The levels and the activity of components of these signaling pathways and of autophagy-related proteins can be altered during ischemic insults. Ischemic stroke activates autophagy, however, whether inhibiting autophagy after stroke is beneficial in the brain is still under a debate. Autophagy is a potential mechanism that may contribute to differences in stroke progression between the sexes. Furthermore, the effects of manipulating autophagy may also differ between the sexes. Mechanisms that regulate autophagy in a sex-dependent manner in ischemic stroke remain unexplored. In this review, we summarize clinical and pre-clinical evidence for sex differences in stroke. We briefly introduce the autophagy process and summarize the effects of gonadal hormones in autophagy in the brain and discuss X-linked genes that could potentially regulate brain autophagy. Finally, we review pre-clinical studies that address the mechanisms that could mediate sex differences in brain autophagy after stroke.
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10
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Colby AE, DeCasien AR, Cooper EB, Higham JP. Greater variability in rhesus macaque ( Macaca mulatta) endocranial volume among males than females. Proc Biol Sci 2022; 289:20220728. [PMID: 36350207 PMCID: PMC9653222 DOI: 10.1098/rspb.2022.0728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 10/05/2022] [Indexed: 11/11/2023] Open
Abstract
The greater male variability (GMV) hypothesis proposes that traits are more variable among males than females, and is supported by numerous empirical studies. Interestingly, GMV is also observed for human brain size and internal brain structure, a pattern which may have implications for sex-biased neurological and psychiatric conditions. A better understanding of neuroanatomical variability in non-human primates may illuminate whether certain species are appropriate models for these conditions. Here, we tested for sex differences in the variability of endocranial volume (ECV, a proxy for brain size) in a sample of 542 rhesus macaques (Macaca mulatta) from a large pedigreed free-ranging population. We also examined the components of phenotypic variance (additive genetic and residual variance) to tease apart the potential drivers of sex differences in variability. Our results suggest that males exhibit more variable ECVs, and that this pattern reflects either balancing/disruptive selection on male behaviour (associated with alternative male mating strategies) or sex chromosome effects (associated with mosaic patterns of X chromosome gene expression in females), rather than extended neurodevelopment among males. This represents evidence of GMV for brain size in a non-human primate species and highlights the potential of rhesus macaques as a model for sex-biased brain-based disorders.
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Affiliation(s)
- Abigail E. Colby
- Department of Anthropology, New York University, New York, NY, USA
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada
| | - Alex R. DeCasien
- Department of Anthropology, New York University, New York, NY, USA
- New York Consortium in Evolutionary Primatology, New York, NY, USA
- Section on Developmental Neurogenomics, National Institutes of Health, Bethesda, MD, USA
| | - Eve B. Cooper
- Department of Anthropology, New York University, New York, NY, USA
- New York Consortium in Evolutionary Primatology, New York, NY, USA
| | - James P. Higham
- Department of Anthropology, New York University, New York, NY, USA
- New York Consortium in Evolutionary Primatology, New York, NY, USA
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11
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Klein L, Van Steenwinckel J, Fleiss B, Scheuer T, Bührer C, Faivre V, Lemoine S, Blugeon C, Schwendimann L, Csaba Z, Bokobza C, Vousden DA, Lerch JP, Vernon AC, Gressens P, Schmitz T. A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity. Glia 2022; 70:1699-1719. [PMID: 35579329 PMCID: PMC9545095 DOI: 10.1002/glia.24190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 11/24/2022]
Abstract
Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1β, we sought to uncover causes of cerebellar damage. In this model, IL-1β is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1β treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1β leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.
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Affiliation(s)
- Luisa Klein
- Department of NeonatologyCharité University Medicine BerlinBerlinGermany
| | | | - Bobbi Fleiss
- NeuroDiderot, InsermUniversité de ParisParisFrance
- School of Health and Biomedical SciencesRMIT UniversityMelbourneVictoriaAustralia
| | - Till Scheuer
- Department of NeonatologyCharité University Medicine BerlinBerlinGermany
| | - Christoph Bührer
- Department of NeonatologyCharité University Medicine BerlinBerlinGermany
| | | | - Sophie Lemoine
- Genomics Core Facility, Département de Biologie, École Normale Supérieure, Institut de Biologie de l'ENS (IBENS), CNRS, INSERMUniversité PSLParisFrance
| | - Corinne Blugeon
- Genomics Core Facility, Département de Biologie, École Normale Supérieure, Institut de Biologie de l'ENS (IBENS), CNRS, INSERMUniversité PSLParisFrance
| | | | - Zsolt Csaba
- NeuroDiderot, InsermUniversité de ParisParisFrance
| | | | - Dulcie A. Vousden
- Mouse Imaging CentreThe Hospital for Sick ChildrenTorontoOntarioCanada
| | - Jason P. Lerch
- Mouse Imaging CentreThe Hospital for Sick ChildrenTorontoOntarioCanada
- Department of Medical BiophysicsUniversity of TorontoTorontoOntarioCanada
- Wellcome Trust Centre for Integrative NeuroimagingUniversity of OxfordOxfordUK
| | - Anthony C. Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and NeuroscienceKing's College LondonLondonUK
- MRC Centre for Neurodevelopmental DisordersKing's College LondonLondonUK
| | | | - Thomas Schmitz
- Department of NeonatologyCharité University Medicine BerlinBerlinGermany
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12
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Sex differences in the human brain: a roadmap for more careful analysis and interpretation of a biological reality. Biol Sex Differ 2022; 13:43. [PMID: 35883159 PMCID: PMC9327177 DOI: 10.1186/s13293-022-00448-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/23/2022] [Indexed: 12/15/2022] Open
Abstract
The presence, magnitude, and significance of sex differences in the human brain are hotly debated topics in the scientific community and popular media. This debate is largely fueled by studies containing strong, opposing conclusions: either little to no evidence exists for sex differences in human neuroanatomy, or there are small-to-moderate differences in the size of certain brain regions that are highly reproducible across cohorts (even after controlling for sex differences in average brain size). Our Commentary uses the specific comparison between two recent large-scale studies that adopt these opposing views-namely the review by Eliot and colleagues (2021) and the direct analysis of ~ 40k brains by Williams and colleagues (2021)-in an effort to clarify this controversy and provide a framework for conducting this research. First, we review observations that motivate research on sex differences in human neuroanatomy, including potential causes (evolutionary, genetic, and environmental) and effects (epidemiological and clinical evidence for sex-biased brain disorders). We also summarize methodological and empirical support for using structural MRI to investigate such patterns. Next, we outline how researchers focused on sex differences can better specify their study design (e.g., how sex was defined, if and how brain size was adjusted for) and results (by e.g., distinguishing sexual dimorphisms from sex differences). We then compare the different approaches available for studying sex differences across a large number of individuals: direct analysis, meta-analysis, and review. We stress that reviews do not account for methodological differences across studies, and that this variation explains many of the apparent inconsistencies reported throughout recent reviews (including the work by Eliot and colleagues). For instance, we show that amygdala volume is consistently reported as male-biased in studies with sufficient sample sizes and appropriate methods for brain size correction. In fact, comparing the results from multiple large direct analyses highlights small, highly reproducible sex differences in the volume of many brain regions (controlling for brain size). Finally, we describe best practices for the presentation and interpretation of these findings. Care in interpretation is important for all domains of science, but especially so for research on sex differences in the human brain, given the existence of broad societal gender-biases and a history of biological data being used justify sexist ideas. As such, we urge researchers to discuss their results from simultaneously scientific and anti-sexist viewpoints.
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13
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Arnold AP. Integrating Sex Chromosome and Endocrine Theories to Improve Teaching of Sexual Differentiation. Cold Spring Harb Perspect Biol 2022; 14:a039057. [PMID: 35667790 PMCID: PMC9438782 DOI: 10.1101/cshperspect.a039057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Major sex differences in mammalian tissues are functionally tied to reproduction and evolved as adaptations to meet different reproductive needs of females and males. They were thus directly controlled by gonadal hormones. Factors encoded on the sex chromosomes also cause many sex differences in diverse tissues because they are present in different doses in XX and XY cells. The sex chromosome effects likely evolved not because of demands of reproduction, but as side effects of genomic forces that adaptively reduced sexual inequality. Sex-specific effects of particular factors, including gonadal hormones, therefore, are not necessarily explained as adaptations for reproduction, but also as potential factors offsetting, rather than producing, sex differences. The incorporation of these concepts would improve future teaching about sexual differentiation.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095-7239, USA
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14
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Sex differences in anxiety and depression: circuits and mechanisms. Nat Rev Neurosci 2021; 22:674-684. [PMID: 34545241 DOI: 10.1038/s41583-021-00513-0] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 02/08/2023]
Abstract
Epidemiological sex differences in anxiety disorders and major depression are well characterized. Yet the circuits and mechanisms that contribute to these differences are understudied, because preclinical studies have historically excluded female rodents. This oversight is beginning to be addressed, and recent studies that include male and female rodents are identifying sex differences in neurobiological processes that underlie features of these disorders, including conflict anxiety, fear processing, arousal, social avoidance, learned helplessness and anhedonia. These findings allow us to conceptualize various types of sex differences in the brain, which in turn have broader implications for considering sex as a biological variable. Importantly, comparing the sexes could aid in the discovery of novel therapeutics.
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15
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Arnold AP. Four Core Genotypes and XY* mouse models: Update on impact on SABV research. Neurosci Biobehav Rev 2020; 119:1-8. [PMID: 32980399 PMCID: PMC7736196 DOI: 10.1016/j.neubiorev.2020.09.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 12/17/2022]
Abstract
The impact of two mouse models is reviewed, the Four Core Genotypes and XY* models. The models are useful for determining if the causes of sex differences in phenotypes are either hormonal or sex chromosomal, or both. Used together, the models also can distinguish between the effects of X or Y chromosome genes that contribute to sex differences in phenotypes. To date, the models have been used to uncover sex chromosome contributions to sex differences in a wide variety of phenotypes, including brain and behavior, autoimmunity and immunity, cardiovascular disease, metabolism, and Alzheimer's Disease. In some cases, use of the models has been a strategy leading to discovery of specific X or Y genes that protect from or exacerbate disease. Sex chromosome and hormonal factors interact, in some cases to reduce the effects of each other. Future progress will come from more extensive application of these models, and development of similar models in other species.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology & Physiology, Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, UCLA, 610 Charles Young Drive South, Los Angeles, CA, 90095-7239, United States.
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16
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X-chromosome regulation and sex differences in brain anatomy. Neurosci Biobehav Rev 2020; 120:28-47. [PMID: 33171144 DOI: 10.1016/j.neubiorev.2020.10.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 10/13/2020] [Accepted: 10/20/2020] [Indexed: 01/08/2023]
Abstract
Humans show reproducible sex-differences in cognition and psychopathology that may be contributed to by influences of gonadal sex-steroids and/or sex-chromosomes on regional brain development. Gonadal sex-steroids are well known to play a major role in sexual differentiation of the vertebrate brain, but far less is known regarding the role of sex-chromosomes. Our review focuses on this latter issue by bridging together two literatures that have to date been largely disconnected. We first consider "bottom-up" genetic and molecular studies focused on sex-chromosome gene content and regulation. This literature nominates specific sex-chromosome genes that could drive developmental sex-differences by virtue of their sex-biased expression and their functions within the brain. We then consider the complementary "top down" view, from magnetic resonance imaging studies that map sex- and sex chromosome effects on regional brain anatomy, and link these maps to regional gene-expression within the brain. By connecting these top-down and bottom-up approaches, we emphasize the potential role of X-linked genes in driving sex-biased brain development and outline key goals for future work in this field.
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17
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Integrative structural, functional, and transcriptomic analyses of sex-biased brain organization in humans. Proc Natl Acad Sci U S A 2020; 117:18788-18798. [PMID: 32690678 DOI: 10.1073/pnas.1919091117] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Humans display reproducible sex differences in cognition and behavior, which may partly reflect intrinsic sex differences in regional brain organization. However, the consistency, causes and consequences of sex differences in the human brain are poorly characterized and hotly debated. In contrast, recent studies in mice-a major model organism for studying neurobiological sex differences-have established: 1) highly consistent sex biases in regional gray matter volume (GMV) involving the cortex and classical subcortical foci, 2) a preponderance of regional GMV sex differences in brain circuits for social and reproductive behavior, and 3) a spatial coupling between regional GMV sex biases and brain expression of sex chromosome genes in adulthood. Here, we directly test translatability of rodent findings to humans. First, using two independent structural-neuroimaging datasets (n > 2,000), we find that the spatial map of sex-biased GMV in humans is highly reproducible (r > 0.8 within and across cohorts). Relative GMV is female biased in prefrontal and superior parietal cortices, and male biased in ventral occipitotemporal, and distributed subcortical regions. Second, through systematic comparison with functional neuroimaging meta-analyses, we establish a statistically significant concentration of human GMV sex differences within brain regions that subserve face processing. Finally, by imaging-transcriptomic analyses, we show that GMV sex differences in human adulthood are specifically and significantly coupled to regional expression of sex-chromosome (vs. autosomal) genes and enriched for distinct cell-type signatures. These findings establish conserved aspects of sex-biased brain development in humans and mice, and shed light on the consistency, candidate causes, and potential functional corollaries of sex-biased brain anatomy in humans.
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18
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Arnold AP. Sexual differentiation of brain and other tissues: Five questions for the next 50 years. Horm Behav 2020; 120:104691. [PMID: 31991182 PMCID: PMC7440839 DOI: 10.1016/j.yhbeh.2020.104691] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 12/16/2022]
Abstract
This paper is part of the celebration of the 50th anniversary of founding of the journal Hormones and Behavior, the official journal of the Society for Behavioral Neuroendocrinology. All sex differences in phenotypic development stem from the sexual imbalance in X and Y chromosomes, which are the only known differences in XX and XY zygotes. The sex chromosome genes act within cells to cause differences in phenotypes of XX and XY cells throughout the body. In the gonad, they determine the type of gonad, leading to differences in secretion of testicular vs. ovarian hormones, which cause further sex differences in tissue function. These current ideas of sexual differentiation are briefly contrasted with a hormones-only view of sexual differentiation of the last century. The multiple, independent action of diverse sex-biasing agents means that sex-biased factors can be synergistic, increasing sex differences, or compensatory, making the two sexes more equal. Several animal models have been fruitful in demonstrating sex chromosome effects, and interactions with gonadal hormones. MRI studies of human brains demonstrate variation in brain structure associated with both differences in gonadal hormones, and in the number of X and Y chromosomes. Five unanswered questions are posed as a challenge to future investigators to improve understanding of sexual differentiation throughout the body.
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Affiliation(s)
- Arthur P Arnold
- Department Integrative Biology and Physiology, University of California, Los Angeles, United States of America.
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19
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Azcoitia I, Barreto GE, Garcia-Segura LM. Molecular mechanisms and cellular events involved in the neuroprotective actions of estradiol. Analysis of sex differences. Front Neuroendocrinol 2019; 55:100787. [PMID: 31513774 DOI: 10.1016/j.yfrne.2019.100787] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/27/2019] [Accepted: 09/07/2019] [Indexed: 12/12/2022]
Abstract
Estradiol, either from peripheral or central origin, activates multiple molecular neuroprotective and neuroreparative responses that, being mediated by estrogen receptors or by estrogen receptor independent mechanisms, are initiated at the membrane, the cytoplasm or the cell nucleus of neural cells. Estrogen-dependent signaling regulates a variety of cellular events, such as intracellular Ca2+ levels, mitochondrial respiratory capacity, ATP production, mitochondrial membrane potential, autophagy and apoptosis. In turn, these molecular and cellular actions of estradiol are integrated by neurons and non-neuronal cells to generate different tissue protective responses, decreasing blood-brain barrier permeability, oxidative stress, neuroinflammation and excitotoxicity and promoting synaptic plasticity, axonal growth, neurogenesis, remyelination and neuroregeneration. Recent findings indicate that the neuroprotective and neuroreparative actions of estradiol are different in males and females and further research is necessary to fully elucidate the causes for this sex difference.
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Affiliation(s)
- Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense de Madrid, 28040 Madrid, Spain; Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludables (CIBERFES), Instituto de Salud Carlos III, Avenida Monforte de Lemos, 3-5, 28029 Madrid, Spain.
| | - George E Barreto
- Department of Biological Sciences, School of Natural Sciences, University of Limerick, Limerick, Ireland.
| | - Luis M Garcia-Segura
- Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludables (CIBERFES), Instituto de Salud Carlos III, Avenida Monforte de Lemos, 3-5, 28029 Madrid, Spain; Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain.
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20
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Fish AM, Nadig A, Seidlitz J, Reardon PK, Mankiw C, McDermott CL, Blumenthal JD, Clasen LS, Lalonde F, Lerch JP, Chakravarty MM, Shinohara RT, Raznahan A. Sex-biased trajectories of amygdalo-hippocampal morphology change over human development. Neuroimage 2019; 204:116122. [PMID: 31470127 PMCID: PMC7485527 DOI: 10.1016/j.neuroimage.2019.116122] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/08/2019] [Accepted: 08/23/2019] [Indexed: 11/25/2022] Open
Abstract
The amygdala and hippocampus are two adjacent allocortical structures implicated in sex-biased and developmentally-emergent psychopathology. However, the spatiotemporal dynamics of amygdalo-hippocampal development remain poorly understood in healthy humans. The current study defined trajectories of volume and shape change for the amygdala and hippocampus by applying a multi-atlas segmentation pipeline (MAGeT-Brain) and semi-parametric mixed-effects spline modeling to 1,529 longitudinally-acquired structural MRI brain scans from a large, single-center cohort of 792 youth (403 males, 389 females) between the ages of 5 and 25 years old. We found that amygdala and hippocampus volumes both follow curvilinear and sexually dimorphic growth trajectories. These sex-biases were particularly striking in the amygdala: males showed a significantly later and slower adolescent deceleration in volume expansion (at age 20 years) than females (age 13 years). Shape analysis localized significant hot-spots of sex-biased anatomical development in sub-regional territories overlying rostral and caudal extremes of the CA1/2 in the hippocampus, and the centromedial nuclear group of the amygdala. In both sexes, principal components analysis revealed close integration of amygdala and hippocampus shape change along two main topographically-organized axes – low vs. high areal expansion, and early vs. late growth deceleration. These results (i) bring greater resolution to our spatiotemporal understanding of amygdalo-hippocampal development in healthy males and females, and (ii) uncover focal sex-differences in the structural maturation of the brain components that may contribute to differences in behavior and psychopathology that emerge during adolescence.
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Affiliation(s)
- Ari M Fish
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Ajay Nadig
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Jakob Seidlitz
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Paul K Reardon
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Catherine Mankiw
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Cassidy L McDermott
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Jonathan D Blumenthal
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Liv S Clasen
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Francois Lalonde
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA
| | - Jason P Lerch
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5T 1R8, Canada; Neurosciences and Mental Health, the Hospital for Sick Children, Toronto, ON, M5T 3H7, Canada
| | - M Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada, H3A OG4; Departments of Psychiatry and Biological and Biomedical Engineering, McGill University, Montreal, QC, H3A OG4, Canada
| | - Russell T Shinohara
- Department of Biostatistics, Epidemiology, and Informatics, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Armin Raznahan
- Developmental Neurogenomics Unit, Human Genetics Branch, National Institute of Mental Health, Bethesda, MD, 20892, USA.
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21
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Arnold AP. The mouse as a model of fundamental concepts related to Turner syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2019; 181:76-85. [PMID: 30779420 DOI: 10.1002/ajmg.c.31681] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 01/10/2019] [Indexed: 12/15/2022]
Abstract
Although XO mice do not show many of the overt phenotypic features of Turner syndrome (TS; 45,X or XO), mice and humans share different classes of genes on the X chromosome that are more or less likely to cause TS phenotypes. Based on the evolutionary history of the sex chromosomes, and the pattern of dosage balancing among sex chromosomal and autosomal genes in functional gene networks, it is possible to prioritize types of X genes for study as potential causes of features of TS. For example, X-Y gene pairs are among the most interesting because of the convergent effects of X and Y genes that both are likely to prevent the effects of TS in XX and XY individuals. Many of the high-priority genes are shared by mouse and human X chromosomes, but are easier to study in genetically tractable mouse models. Several mouse models, used primarily for the study of sex differences in physiology and disease, also produce XO mice that can be investigated to understand the effects of X monosomy. Using these models will lead to the identification of specific X genes that make a difference when present in one or two copies. These studies will help to achieve a better appreciation of the contribution of these specific X genes to the syndromic features of TS.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology and Physiology, Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California
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22
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Abstract
Evolution of genetic mechanisms of sex determination led to two processes causing sex differences in somatic phenotypes: gonadal differentiation and sex chromosome dosage inequality. In species with heteromorphic sex chromosomes, the sex of the individual is established at the time of formation of the zygote, leading to inherent sex differences in expression of sex chromosome genes beginning as soon as the embryonic transcriptome is activated. The inequality of sex chromosome gene expression causes sexual differentiation of the gonads and of non-gonadal tissues. The difference in gonad type in turn causes lifelong differences in gonadal hormones, which interact with unequal effects of X and Y genes acting within cells. Separating the effects of gonadal hormones and sex chromosomes has been possible using mouse models in which gonadal determination is separated from the sex chromosomes, allowing comparison of XX and XY mice with the same type of gonad. Sex differences caused by gonadal hormones and sex chromosomes affect basic physiology and disease mechanisms in most or all tissues.
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