Background: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism.
Methods: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism.
Results: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients.
Conclusions: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism.
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http://dx.doi.org/10.1016/j.biopsych.2005.11.011 | DOI Listing |
Parasit Vectors
December 2024
Parasitology and Entomology Research Cluster (PERC), Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
Background: Fast and reliable species identification of black flies is essential for research proposes and effective vector control. Besides traditional identification based on morphology, which is usually supplemented with molecular methods, geometric morphometrics (GM) has emerged as a promising tool for identification. Despite its potential, no specific GM techniques have been established for the identification of black fly species.
View Article and Find Full Text PDFNeurol Med Chir (Tokyo)
December 2024
Department of Pediatric Neurosurgery, Matsudo City General Hospital.
To provide appropriate treatment, neurosurgeons and pediatricians must understand the chronological changes of the cranial morphology in normal children and the differences between normal and sagittal synostosis children. However, this issue has remained unresolved due to the traditional methods of analyzing cranial morphology. Therefore, we applied a new and precise method, geometric morphometrics, to understand cranial morphology in children with normal and sagittal synostosis.
View Article and Find Full Text PDFAn Acad Bras Cienc
December 2024
Universidad de la República, Facultad de Ciencias, Instituto de Ciencias Geológicas, Departamento de Paleontología, Iguá, 4225, 11400, Montevideo, Uruguay.
Understanding shell morphology is central to taxonomic and evolutionary studies of bivalves. When traditional systematic studies find limitations in the recognition and classification of taxa, geometric morphometrics methods become a tool to tackle these uncertainties. Taxonomic difficulties are frequently found in systematics studies of the generally homoplastic Pitarinae (Venereidae).
View Article and Find Full Text PDFPLoS One
December 2024
Departamento de Matemática Aplicada, Instituto de Matemática, Estatística e Computação Científica (IMECC), Universidade Estadual de Campinas, Campinas, Brazil.
Species delimitation in hard corals remains controversial even after 250+ years of taxonomy. Confusing taxonomy in Scleractinia is not the result of sloppy work: clear boundaries are hard to draw because most diagnostic characters are quantitative and subjected to considerable morphological plasticity. In this study, we argue that taxonomists may actually be able to visually discriminate among morphospecies, but fail to translate their visual perception into accurate species descriptions.
View Article and Find Full Text PDFProc Biol Sci
December 2024
Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
Ecology is a key driver of morphological evolution during adaptive radiations, but alternative factors like phylogeny and allometry can have a strong influence on morphology. Lepidosaurs, the most diverse clade of tetrapods, including lizards and snakes, have evolved a remarkable variety of forms and adapted to disparate ecological niches, representing an ideal case study to understand drivers of morphological evolution. Here, we quantify morphological variation in the lower jaw using three-dimensional geometric morphometrics on a broad sample of 153 lepidosaur species.
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