Multi-level analysis of cortical neuroanatomy in Williams syndrome

The purpose of a neuroanatomical analysis of Williams Syndrome (WMS) brains is to help bridge the knowledge of the genetics of this disorder with the knowledge on behavior. Here, we outline findings of cortical neuroanatomy a t multiple levels. We describe the gross anatomy with respect to brain shap e, cortical folding, and asymmetry. This, as with most neuroanatomical info rmation available in the literature on anatomical-functional correlations, links up best to the behavioral profile. Then, we describe the cytoarchitec tonic appearance of the cortex. Further, we report on some histometric resu lts. Finally, we present finding of immunocytochemistry that attempt to lin k up to the genomic deletion. The gross anatomical findings consist mainly of a small brain that shows curtailment in the posterior-parietal and occip ital regions. There is also subtle dysmorphism of cortical folding. A consi stent finding is a short central sulcus that does not become opercularized in the interhemispheric fissure, bringing attention to a possible developme ntal anomaly affecting the dorsal half of the hemispheres. There is also la ck of asymmetry in the planum temporale. The cortical cytoarchitecture is r elatively normal, with all sampled areas showing features typical of the re gion from which they are taken. Measurements in area 17 show increased cell size and decreased cell-packing density, which address the issue of possib le abnormal connectivity. Immunostaining shows absence of elastin but norma l staining for Lim-1 kinase, both of which are products of genes that are p art of the deletion. Finally, one serially sectioned brain shows a fair amo unt of acquired pathology of microvascular origin related most likely to un derlying hypertension and heart disease.