Investigating the barrel cortex morphology in the rat valproic acidmodel of autism

Aim: Autism is a neurodevelopmental disorder that is characterized by sociability problems and repetitive and stereotypic behaviors. More than 90% of autistic people experience abnormal perception accompanied with hypo or hyperreactivity to stimuli and altered sensory coding and integration. Barrel cells are groups of cells in the rodent somatosensory cortex that receive sensory information from. Lesioning a whisker in early neonatal period induces somatotopographical changes in the barrel cortex. Analyzing dendritic structures provides important knowledge on abnormal synaptic connections and circuits. This study aimed to investigate the morphological changes in somatosensory cortices in an animal model of autism. Methods: In rats, autistic phenotype was created by prenatal valproic acid exposure. In one group, whiskers were lesioned and morphological changes were investigated by calculating the volumes of barrels. In the other group, differences at the cellular level were examined at the dendritic morphology level by Golgi-Cox staining for lamina 4 and 5 neurons. Results: No difference was observed in barrel volumes and dendritic morphologies of lamina 4 neurons, which receive thalamocortical inputs in the somatosensory cortex. In lamina 5 pyramidal neurons which transmit the output, an increase in the dendritic branching, a weakening of the spines and an increase in spine density was observed for. Conclusion: In this autism model created by prenatal valproic acid exposure in rats, morphological abnormalities varying according to cell and dendrite type indicate aberrations confined to the local circuit.