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Dyslexia and Irregular Dynamics of the Visual System
Published in Kees P. van den Bos, Linda S. Siegel, Dirk J. Bakker, David L. Share, Current Directions in Dyslexia Research, 2020
The few autopsies on dyslexics show cytoarchitectural distortions in the left hemisphere, such as excessive number of neurons in the deeper layers of the neocortex and relatively few in the upper layers (Galaburda, 1983; Kemper, 1984). So, it is conceivable–without speculating about the dominance of excitatory or inhibitory neurons in some layers–that in cytoarchitectural distorted parts of the neocortex there are relatively few excitatory and/or inhibitory neurons compared to unaffected parts of the neocortex. Obviously, a reduced number of neurons in a neuronal net also reduces the number of possible synaptic relays. For a neuronal net containing relatively few neurons and/or synaptic relays we will adopt the term reduced net. When one compares the results of the different autopsies different maps of ectopies show up. This leaves the impression that the locations of ectopies are randomly distributed. If so, it is a matter of chance which areas involved in the process of reading and writing are affected (visual cortex, gyrus angularis etc.). And it seems a matter of chance too that an area such as the premotor area for generating voluntary (saccadic) eye movements is also affected. This point of view can explain why anomalous eye movements are occasionally seen in dyslexics.
Biological Predictions from the Conduction Delay Hypothesis of Cerebral Lateralization
Published in Robert Miller, Axonal Conduction Time and Human Cerebral Laterality, 2019
On the left, both the prefrontal and the temporal speech areas are larger than the corresponding areas on the right, whether the areas are defined by gyral pattern or on cytoarchitectural grounds. According to Falzi et al. (1982) there is no relation between the degree of asymmetry seen in the anterior and the posterior speech areas. There also appear to be subtle cytoarchitectural differences between sides in both areas, which fact provokes an attempt at explanation in terms of information processing in language (see Chapter 8). For instance, the larger lamina III pyramidal cells in the anterior speech area, and the wider spacing of neurones in the posterior speech area (compared with the opposite sides) might be a consequence of cortico-cortical cells in the anterior region projecting to the posterior region and having richer terminal arborizations there on the left side than the corresponding region on the right side. In the inferior parietal area, one cytoarchitectural area was consistently larger on the right, another on the left (the latter correlating with the size of the planum temporale). The measurements which have been made of the size of individual cytoarchitectural areas are highly selected data. It is possible that many other lateral differences might be found if they were looked for.
The Ultrastructure And Pathobiology Of Urinary Bladder Cancer
Published in George T. Bryan, Samuel M. Cohen, The Pathology of Bladder Cancer, 2017
Bendicht U. Pauli, Joseph Alroy, Ronald S Weinstein
At the ultrastructural level, all three lines are similar, when grown on either plastic or on collagen-coated Nitex disks (see Figure 59B). Plasma membranes of the tumor cells are 9-nm-thick symmetric unit membranes. AUM-plaques are not observed.296 Lumenal plasma membranes are covered by a sparse glycocalyx and display numerous pleomorphic microvilli at the free surface. Nuclei vary in size and chromatin distribution. The nuclear envelope typically has many shallow infoldings. The tumor cell cytoplasm has a relatively simple cytoarchitecture. It is characterized by the presence of a few clustered mitochondria and numerous free ribosomes. Smooth and rough endoplasmic reticulum are poorly developed. The Golgi apparatus is usually prominent and often multicentric. Secondary lysosomes are plentiful in thin sections in some cells and absent in others. Intracytoplasmic lumina are observed in the cultures. Squamous differentiation is observed in cultures of all three lines, including the development of prominent bundles of tonofilaments.296 On collagen-coated Nitex disks, basal tumor cells lack a basal lamina and grow in direct contact with the collagenous substratum. There are no hemidesmosomes anchoring the basal plama membrane to collagenous fibers.412
A primer on modelling pancreatic islets: from models of coupled β-cells to multicellular islet models
Published in Islets, 2023
Gerardo J. Félix-Martínez, J. Rafael Godínez-Fernández
While previous models had focused mainly on synchronization, noise, cellular heterogeneity, wave propagation and hub cells, Nittala et al.76 focused on investigating the functional implications of cytoarchitecture (i.e. number of β -cells, connectivity and coupling strength), a relevant aspect not considered in detail in previous models. They proposed the HCP geometry for models of pancreatic islets and evaluated how the cytoarchitecture influenced the fraction of bursting β-cells, the bursting period, plateau fraction and synchronization, as well as the amplitude of intracellular Ca2+ oscillations. In a latter work, the same group,124 based on extensive simulations, proposed a cytoarchitectural integrity descriptor denominated cluster coupling index as a measure of morphological and structural integrity of the islet.
Ameliorative effects of hexane extract of Garcinia kola seeds Heckel (Clusiaceae) in cisplatin-induced hepatorenal toxicity in mice
Published in Drug and Chemical Toxicology, 2022
Adeniyi Folayan, Emmanuel Akani, Olayinka A. Adebayo, Olubukola O. Akanni, Solomon E. Owumi, Abiola S. Tijani, Oluwatosin A. Adaramoye
The number of mononucleated polychromatic erythrocytes was higher in the bone marrow of cisplatin-treated mice relative to control. This could be a result of high oxidant concentration in the bone marrow, causing DNA damage. These data are in agreement with the report of Orsolic and Car (2014), which demonstrated that Cisplatin might induce clastogenicity in an animal model. Interestingly, pretreatment with HEGK reduced the number of micronuclei in the red cells. Histological examination of liver and kidney from cisplatin-treated mice revealed necrosis of hepatic tissue, widespread congestion of renal interstitial vessel, and hyperplasia of the Kupffer cells. Pretreatment with HEGK restored the cytoarchitecture of these tissues. The biological activities shown by HEGK could be linked to the presence of certain polyphenols such as lupeol, tirucallol, β-amyrin, etc as revealed by GCMS, which are known to elicit antioxidant, anti-inflammatory, anticancer and anti-diabetic properties (Fernandez-Arche et al.2010; Elmi et al.2020; Khurshid et al.2020).
A quick and versatile protocol for the 3D visualization of transgene expression across the whole body of larval Drosophila
Published in Journal of Neurogenetics, 2021
Oliver Kobler, Aliće Weiglein, Kathrin Hartung, Yi-chun Chen, Bertram Gerber, Ulrich Thomas
Pioneered by Werner Spalteholz a century ago, tissue clearing proved to be a groundbreaking technique in microscopic anatomy (Eisenstein, 2018; Spalteholz, 1911) once optimized protocols were combined with state-of-the-art cell labeling, microscopy, and image data processing (Ueda et al., 2020). This paved the way for striking insights into the morphology and cytoarchitecture of relatively large, intact, and complete organs, including mammalian brains and indeed their neuronal projections throughout the body (Cai et al., 2019). Given that these approaches work for animals the size of a mouse and ‘through skin and bone’, it might have seemed trivial to apply them to much smaller animals such as Drosophila, too. The cuticular exoskeleton of arthropods, however, proves to be a tricky obstacle to clearing. A recent protocol (Pende et al., 2018) has addressed this problem with remarkable success and was documented and optimized for pupal and adult stages.