In the human brain, the corpus callosum is the major white-matter commissural tract enabling the transmission of sensory-motor, and higher level cognitive information between homotopic regions of the two cerebral hemispheres. Despite developmental absence (i.e., agenesis) of the corpus callosum (AgCC), functional connectivity is preserved, including interhemispheric connectivity. Subcortical structures have been hypothesised to provide alternative pathways to enable this preservation. To test this hypothesis, we used functional Magnetic Resonance Imaging (fMRI) recordings in children with AgCC and typically developing children, and a time-resolved approach to retrieve temporal characteristics of whole-brain functional networks. We observed an increased engagement of the cerebellum and amygdala/hippocampus networks in children with AgCC compared to typically developing children. There was little evidence that laterality of activation networks was affected in AgCC. Our findings support the hypothesis that subcortical structures play an essential role in the functional reconfiguration of the brain in the absence of a corpus callosum.
Bibliographical note©2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/)
Funding: This study was supported by the Boninchi Foundation from the University of Geneva; the Victorian Government’s Operational Infrastructure Support Program; and the Murdoch Children’s Research Institute. Younes Farouj and Anjali Tarun are supported by the Swiss National Science Foundation Project [205321_163376]. Professor Amanda G. Wood is supported by a European Research Council Consolidator Fellowship . Associate Professor Richard J. Leventer is supported by a Melbourne Children’s Clinician Scientist Fellowship. Professor Vicki Anderson was supported by the Australian National Health and Medical Research Council Senior Practitioner Fellowship.
- Brain plasticity
- Callosal agenesis
- Dynamic functional connectivity
- Subcortical networks