Autism: a molecular plasticity disorder

Background and AimsAutism (MIM#209850) is a complex neurodevelopmental affection that is largely genetic psychiatric disorder. Several genes have been found associated with autism but their expression levels and neuropathological effects remain unknown in autistic brain.MethodsWe compare the level of expression of autism candidate genes in post-mortem brain region samples between controls and patients. We studied Brodmann area (BA) 46 and the granule cells of the cerebellum lobule 6, for which neuropathological findings and functional abnormalities have been reported in autism.ResultsDifferent levels of transcription for SLC25A12/AGC1, EN2 and Nr-CAM genes are observed in the cortex and granule cells. Difference of expression are observed between patients and controls. We focused on SLC25A12 for which polymorphisms have been associated to autism in various studies. SLC25A12 encodes the mitochondrial aspartate/glutamate carrier and its function is requested to produce energy in neurons. By hybridation in situ, we analysed the expression pattern of SLC25A12 in human development and we studied the effects of SLC25A12 over-expression on mouse embryonic cortical neurons.ConclusionsConvergent evidence suggest that level of expression of candidate genes may be involved in autism pathophysiology by modifying neuronal networks and molecular plasticity in specific brain subregions at both pre- and postnatal stages.SponsorAutism Tissue Program and Federation pour la Recherche sur le Cerveau