{"id":61516,"date":"2018-06-07T14:47:59","date_gmt":"2018-06-07T12:47:59","guid":{"rendered":"https:\/\/neurodev-ng.u-bordeaux.fr\/f-crivello-n-tzourio-mazoyer-et-al-inpnas\/"},"modified":"2018-06-07T14:47:59","modified_gmt":"2018-06-07T12:47:59","slug":"f-crivello-n-tzourio-mazoyer-et-al-inpnas","status":"publish","type":"post","link":"https:\/\/www.bordeaux-neurocampus.fr\/en\/f-crivello-n-tzourio-mazoyer-et-al-inpnas\/","title":{"rendered":"F.Crivello, N.Tzourio-Mazoyer et al. inPNAS<\/em>"},"content":{"rendered":"
\n

Mapping cortical brain asymmetry in 17,141 healthy individuals worldwide via the ENIGMA Consortium.<\/strong> Xiang-Zhen Kong, Samuel R. Mathias, Tulio Guadalupe, ENIGMA Laterality Working\u00a0<\/em>Group, David C. Glahn, Barbara Franke, Fabrice Crivello, Nathalie Tzourio Mazoyer,\u00a0<\/em>Simon E. Fisher, Paul M. Thompson, and Clyde Francks. PNAS May 15, 2018. 201718418; published ahead of print May 15, 2018. https:\/\/doi.org\/10.1073\/pnas.1718418115
\n<\/a><\/em>
\nFabrice Crivello & Nathalie Tzourio-Mazoyer
\n<\/strong>Groupe d\u2019Imagerie Neurofonctionnelle – Institut des Maladies Neurod\u00e9g\u00e9n\u00e9ratives
\n<\/strong>CNRS UMR 5293- CEA-Universit\u00e9 de Bordeaux \/ 33076 Bordeaux cedex
\n<\/span><\/p>\n

\n

Au sein du consortium international ENIGMA<\/strong> (Enhancing Neuro Imaging Genetics\u00a0through Meta-Analysis), des chercheurs du Groupe d\u2019Imagerie Neurofonctionelle\u00a0(IMN)et du Max Planck Institute for Psycholinguinstics ont caract\u00e9ris\u00e9 les asym\u00e9tries\u00a0de surface et d\u2019\u00e9paisseur du cortex c\u00e9r\u00e9bral de 17 141 individus. Cette \u00e9tude, publi\u00e9e\u00a0dans PNAS, pr\u00e9sente une caract\u00e9risation des asym\u00e9tries structurelles et de leur\u00a0variabilit\u00e9. Elle fournit ainsi une source de r\u00e9f\u00e9rence unique pour de futures \u00e9tudes sur\u00a0les bases g\u00e9n\u00e9tiques des asym\u00e9tries c\u00e9r\u00e9brales et l\u2019alt\u00e9ration de la lat\u00e9ralisation au\u00a0cours de troubles cognitifs, neurologiques et psychiatriques.<\/p>\n


\nD\u00e9chiffrer les asym\u00e9tries anatomiques c\u00e9r\u00e9brales pour mieux comprendre la\u00a0<\/strong>sp\u00e9cialisation h\u00e9misph\u00e9rique<\/strong><\/p>\n

\"F<\/a>
F Crivello, N.Tzourio-Mazoyer<\/figcaption><\/figure>\n

L’asym\u00e9trie anatomique des h\u00e9misph\u00e8res<\/strong> c\u00e9r\u00e9braux est une caract\u00e9ristique\u00a0fondamentale de l’organisation du cerveau humain. Mais, la lat\u00e9ralisation c\u00e9r\u00e9brale\u00a0n\u2019est pas seulement anatomique, elle est aussi fonctionnelle. On la retrouve dans\u00a0diverses aptitudes cognitives comme le langage, la perception des visages, le\u00a0traitement visuo-spatial ou le raisonnement. D\u00e9chiffrer cette sp\u00e9cialisation\u00a0fonctionnelle h\u00e9misph\u00e9rique est un enjeu central des recherches en neurosciences\u00a0pour comprendre le fonctionnement du cerveau, mais aussi ses dysfonctionnements.\u00a0Une alt\u00e9ration de la lat\u00e9ralisation h\u00e9misph\u00e9rique a en effet \u00e9t\u00e9 associ\u00e9e \u00e0 de\u00a0nombreux troubles cognitifs et neuropsychiatriques comme la dyslexie, les troubles\u00a0d\u00e9ficitaires de l’attention et l\u2019hyperactivit\u00e9, la schizophr\u00e9nie et l\u2019autisme ainsi que la\u00a0maladie d\u2019Alzheimer.<\/p>\n

Aujourd\u2019hui, bien que les asym\u00e9tries structurelles et fonctionnelles soient susceptibles\u00a0d’\u00eatre interd\u00e9pendantes, la nature de leurs relations est loin d’\u00eatre clarifi\u00e9e. Une des\u00a0principales difficult\u00e9s repose sur la capacit\u00e9 \u00e0 d\u00e9terminer au niveau de la population,\u00a0c\u2019est \u00e0 dire sur de tr\u00e8s large \u00e9chantillon, quelles structures c\u00e9r\u00e9brales sont r\u00e9ellement\u00a0anatomiquement asym\u00e9triques. Gr\u00e2ce \u00e0 des moyens jusque-l\u00e0 in\u00e9dits, cette \u00e9tude\u00a0vient \u00e9clairer d\u2019un jour nouveau nos connaissances sur les asym\u00e9tries anatomiques\u00a0c\u00e9r\u00e9brales.<\/p>\n

Une \u00e9tude d\u2019une envergure in\u00e9dite sur la caract\u00e9risation des asym\u00e9tries\u00a0<\/strong>anatomiques c\u00e9r\u00e9brales chez l\u2019homme<\/strong><\/p>\n

Ce sont plus 34000 h\u00e9misph\u00e8res, issus de 99 cohortes internationales et\u00a0ind\u00e9pendantes, qui ont \u00e9t\u00e9 analys\u00e9s pour cette \u00e9tude de neuroimagerie en population.\u00a0Pour cela, le consortium international ENIGMA a mis en place la plus grande analyse\u00a0de l’asym\u00e9trie corticale c\u00e9r\u00e9brale et de sa variabilit\u00e9 \u00e0 travers les individus jamais\u00a0r\u00e9alis\u00e9e. 17 141 individus ont ainsi effectu\u00e9 un examen d\u2019IRM afin de mesurer\u00a0l\u2019\u00e9paisseur et la surface corticale de chacun de leurs h\u00e9misph\u00e8res c\u00e9r\u00e9braux.<\/p>\n

La pr\u00e9sente \u00e9tude montre qu\u2019\u00e0 l\u2019\u00e9chelle h\u00e9misph\u00e9rique, les profils d\u2019asym\u00e9tries\u00a0d\u2019\u00e9paisseur et de surface du cortex c\u00e9r\u00e9bral sont diff\u00e9rents. Le cortex humain appara\u00eet\u00a0en moyenne plus \u00e9pais \u00e0 gauche, mais il pr\u00e9sente une plus grande surface \u00e0 droite.\u00a0Des \u00e9tudes r\u00e9alis\u00e9es sur des \u00e9chantillons plus restreints ont pr\u00e9c\u00e9demment\u00a0sugg\u00e9r\u00e9es que l’\u00e9paisseur et la surface corticale \u00e9taient g\u00e9n\u00e9tiquement et\u00a0d\u00e9veloppementalement distincts et qu\u2019il \u00e9tait important de consid\u00e9rer ces deux aspects\u00a0\u00a0de l’anatomie corticale s\u00e9par\u00e9ment. Les r\u00e9sultats obtenus ici confirment ces\u00a0diff\u00e9rences et renforce leur nature ind\u00e9pendante.<\/p>\n

\"\"<\/a>
Au sein du consortium ENIGMA les asym\u00e9tries d\u2019\u00e9paisseur (A) et de surface (B) du cortex c\u00e9r\u00e9bral de 17 141 individus ont \u00e9t\u00e9 mesur\u00e9es par IRM.<\/figcaption><\/figure>\n

Au niveau des r\u00e9gions c\u00e9r\u00e9brales, des asym\u00e9tries d’\u00e9paisseur et\/ou de surface\u00a0corticale ont \u00e9t\u00e9 trouv\u00e9es dans les r\u00e9gions \u00e9tant impliqu\u00e9es dans des fonctions\u00a0fortement lat\u00e9ralis\u00e9es comme le langage et le traitement visuo-spatial (le gyrus frontal\u00a0inf\u00e9rieur, le gyrus temporal transversal, le gyrus para-hippocampique et le cortex\u00a0entorhinal), sugg\u00e9rant ainsi leur r\u00f4le important dans la sp\u00e9cialisation h\u00e9misph\u00e9rique.
\n
\n<\/span><\/p>\n

Autre fait int\u00e9ressant, aucune association significative entre les asym\u00e9tries corticale et\u00a0la pr\u00e9f\u00e9rence manuelle n\u2019a \u00e9t\u00e9 trouv\u00e9e, venant confirmer des r\u00e9sultats d\u00e9j\u00e0 obtenus\u00a0par les chercheurs de l\u2019\u00e9quipe GIN-IMN. Cette absence de relation d\u00e9montre ainsi que\u00a0la gaucherie n\u2019implique aucune alt\u00e9ration des asym\u00e9tries corticales.<\/p>\n

Abstract<\/strong>
\n<\/em>Hemispheric asymmetry is a cardinal feature of human brain organization. Altered brain asymmetry has also been linked to some cognitive and neuropsychiatric disorders. Here, the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Consortium presents the largest-ever analysis of cerebral cortical asymmetry and its variability across individuals. Cortical thickness and surface area were assessed in MRI scans of 17,141 healthy individuals from 99 datasets worldwide. Results revealed widespread asymmetries at both hemispheric and regional levels, with a generally thicker cortex but smaller surface area in the left hemisphere relative to the right. Regionally, asymmetries of cortical thickness and\/or surface area were found in the inferior frontal gyrus, transverse temporal gyrus, parahippocampal gyrus, and entorhinal cortex. These regions are involved in lateralized functions, including language and visuospatial processing. In addition to population-level asymmetries, variability in brain asymmetry was related to sex, age, and intracranial volume. Interestingly, we did not find significant associations between\u00a0<\/em>asymmetries and handedness. Finally, with two independent pedigree datasets (n = 1,443 and 1,113, respectively), we found several asymmetries showing significant, replicable heritability. The structural asymmetries identified and their variabilities and heritability provide a reference resource for future studies on the genetic basis of brain asymmetry and altered laterality in cognitive, neurological, and psychiatric disorders.<\/em>\u00a0<\/em><\/p>\n<\/div>\n

fabrice.crivello@u-bordeaux.fr<\/a> \/ nathalie.tzourio-mazoyer@u-bordeaux.fr<\/a><\/p>\n

Derni\u00e8re mise \u00e0 jour le 12.06.2018<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Mapping cortical brain asymmetry in 17,141 healthy individuals worldwide via the ENIGMA Consortium. <\/p>\n","protected":false},"author":108,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[71],"tags":[],"class_list":["post-61516","post","type-post","status-publish","format-standard","hentry","category-highlight-en"],"_links":{"self":[{"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/posts\/61516","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/users\/108"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/comments?post=61516"}],"version-history":[{"count":0,"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/posts\/61516\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/media?parent=61516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/categories?post=61516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bordeaux-neurocampus.fr\/en\/wp-json\/wp\/v2\/tags?post=61516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}