1. Neonatal valproic acid exposure produces altered gyrification related to increased parvalbumin-immunopositive neuron density with thickened sulcal floors
- Author
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Ichio Aoki, Kazuhiko Sawada, and Shiori Kamiya
- Subjects
Central Nervous System ,Male ,Pervasive Developmental Disorders ,Autism Spectrum Disorder ,Social Sciences ,Gene Expression ,Cell Count ,Nervous System ,Diagnostic Radiology ,Animal Cells ,Cortex (anatomy) ,Parietal Lobe ,Medicine and Health Sciences ,Morphogenesis ,Psychology ,Gyrification ,Mammals ,Neurons ,Cerebral Cortex ,Brain Mapping ,Multidisciplinary ,Radiology and Imaging ,Lateral sulcus ,Eukaryota ,Brain ,Anatomy ,Sulcus ,Magnetic Resonance Imaging ,Immunohistochemistry ,Temporal Lobe ,Cortical Neurogenesis ,Frontal Lobe ,medicine.anatomical_structure ,Parvalbumins ,Cerebral cortex ,Vertebrates ,Medicine ,lipids (amino acids, peptides, and proteins) ,Anticonvulsants ,Cellular Types ,Injections, Intraperitoneal ,Research Article ,Imaging Techniques ,Science ,Neurogenesis ,Central nervous system ,Neuroimaging ,Biology ,Research and Analysis Methods ,Developmental Neuroscience ,Diagnostic Medicine ,medicine ,Animals ,Humans ,Valproic Acid ,Organisms ,Ferrets ,Biology and Life Sciences ,Cell Biology ,Animals, Newborn ,Cellular Neuroscience ,Amniotes ,Developmental Psychology ,biology.protein ,Neuron ,Zoology ,Cerebral Hemispheres ,Parvalbumin ,Biomarkers ,Neuroscience - Abstract
Valproic acid (VPA) treatment is associated with autism spectrum disorder in humans, and ferrets can be used as a model to test this; so far, it is not known whether ferrets react to developmental VPA exposure with gyrencephalic abnormalities. The current study characterized gyrification abnormalities in ferrets following VPA exposure during neonatal periods, corresponding to the late stage of cortical neurogenesis as well as the early stage of sulcogyrogenesis. Ferret pups received intraperitoneal VPA injections (200 μg/g of body weight) on postnatal days (PD) 6 and 7. BrdU was administered simultaneously at the last VPA injection. Ex vivo MRI-based morphometry demonstrated significantly lower gyrification index (GI) throughout the cortex in VPA-treated ferrets (1.265 ± 0.027) than in control ferrets (1.327 ± 0.018) on PD 20, when primary sulcogyrogenesis is complete. VPA-treated ferrets showed significantly smaller sulcal-GIs in the rostral suprasylvian sulcus and splenial sulcus but a larger lateral sulcus surface area than control ferrets. The floor cortex of the inner stratum of both the rostral suprasylvian and splenial sulci and the outer stratum of the lateral sulcus showed a relatively prominent expansion. Parvalbumin-positive neuron density was significantly greater in the expanded cortical strata of sulcal floors in VPA-treated ferrets, regardless of the BrdU-labeled status. Thus, VPA exposure during the late stage of cortical neurogenesis may alter gyrification, primarily in the frontal and parietotemporal cortical divisions. Altered gyrification may thicken the outer or inner stratum of the cerebral cortex by increasing parvalbumin-positive neuron density.
- Published
- 2021