1. Dysfunctional Autism Risk Genes Cause Circuit-Specific Connectivity Deficits With Distinct Developmental Trajectories
- Author
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Zerbi, Valerio, Ielacqua, Giovanna D, Markicevic, Marija, Haberl, Matthias Georg, Ellisman, Mark H, A-Bhaskaran, Arjun, Frick, Andreas, Rudin, Markus, and Wenderoth, Nicole
- Subjects
Biological Psychology ,Biomedical and Clinical Sciences ,Psychology ,Basic Behavioral and Social Science ,Neurosciences ,Autism ,Pediatric ,Intellectual and Developmental Disabilities (IDD) ,Behavioral and Social Science ,Genetics ,Mental Health ,Brain Disorders ,2.1 Biological and endogenous factors ,Aetiology ,Neurological ,Mental health ,Age Factors ,Animals ,Animals ,Newborn ,Autistic Disorder ,Brain ,Brain Mapping ,Connectome ,Disease Models ,Animal ,Fragile X Mental Retardation Protein ,Image Processing ,Computer-Assisted ,Luminescent Proteins ,Magnetic Resonance Imaging ,Membrane Proteins ,Mice ,Mice ,Inbred C57BL ,Mice ,Knockout ,Nerve Tissue Proteins ,Neural Pathways ,Oxygen ,Transduction ,Genetic ,autism ,brain connectivity ,CNTNAP2 ,FMR1 ,resting-state functional MRI ,Cognitive Sciences ,Experimental Psychology ,Biological psychology ,Cognitive and computational psychology - Abstract
Autism spectrum disorders (ASD) are a set of complex neurodevelopmental disorders for which there is currently no targeted therapeutic approach. It is thought that alterations of genes regulating migration and synapse formation during development affect neural circuit formation and result in aberrant connectivity within distinct circuits that underlie abnormal behaviors. However, it is unknown whether deviant developmental trajectories are circuit-specific for a given autism risk-gene. We used MRI to probe changes in functional and structural connectivity from childhood to adulthood in Fragile-X (Fmr1-/y) and contactin-associated (CNTNAP2-/-) knockout mice. Young Fmr1-/y mice (30 days postnatal) presented with a robust hypoconnectivity phenotype in corticocortico and corticostriatal circuits in areas associated with sensory information processing, which was maintained until adulthood. Conversely, only small differences in hippocampal and striatal areas were present during early postnatal development in CNTNAP2-/- mice, while major connectivity deficits in prefrontal and limbic pathways developed between adolescence and adulthood. These findings are supported by viral tracing and electron micrograph approaches and define 2 clearly distinct connectivity endophenotypes within the autism spectrum. We conclude that the genetic background of ASD strongly influences which circuits are most affected, the nature of the phenotype, and the developmental time course of the associated changes.
- Published
- 2018