Consulta: subjectFacets:"Corpus callosum"
Registros recuperados: 9
Data/hora: 11/06/2024 04:32:21

Effects of Visual Loss in the Corpus Callosum in Rats Subjected to Sensory-Motor Training
Provedor de dados: 77
Autores: Suazo Galdames,Iván; López Farías,Bernarda; Cantín López,Mario.
The purpose of this study was to analyze the changes in the dimensions of different portions of the corpus callosum in rats subjected to sensory-motor enriched environment with visual loss. We used 24 adult Sprague­Dawley rats divided into three groups: G1 (n = 7) control, G2 (n = 10) subjected to sensory-motor stimulation, and G3 (n = 7) subjected to sensory-motor stimulation followed by visual loss by retinal injury. The brains were extracted and the corpus callosum was divided into three parts of equal length, corresponding to the genu, mid-body, and splenium, and the callosal area was determined according to the method described by Aboitiz et al. (1992). We observed normal performance among animals in G2 and G3 in the enriched environment with a...
Tipo: Journal article
Palavras-chave: Corpus callosum; Esplenium; Visual cortex; Motor performance.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022009000400012

Corpus Callosum Size, is There a Sexual Difference?
Provedor de dados: 77
Autores: Yasin,Mohammad; Farahani,Reza Mastery.
Physical anthropometry is a subdivision of human anatomy science, which has uses in medical industries. A lot of studies showed that genetic, racial, and socioeconomic factors and educational background play rule in anthropometry. We aim this study to determine the presence of differences between gender and corpus callosum size. MRIs were collected from Ardebil and Kermanshah states done in 2013, the participants were informed about this study. They were selected based on age more than 20-years old, absence of demyelization and degenerative diseases, clean history of for neurosurgery, and previous cerebrovascular accidents. MRIs were analyzed by PmsDview program in the midsagittal section by using 9 landmarks, and the data was analyzed by SPSS 19.0. The...
Tipo: Journal article
Palavras-chave: Corpus callosum; Sex-related size; Sex-related; Anthropometry; Iran; MRI; Sexual dimorphism.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000100016

Long distance communication in the human brain: timing constraints for inter-hemispheric synchrony and the origin of brain lateralization
Provedor de dados: 48
Autores: ABOITIZ,FRANCISCO; LÓPEZ,JAVIER; MONTIEL,JUAN.
Analysis of corpus callosum fiber composition reveals that inter-hemispheric transmission time may put constraints on the development of inter-hemispheric synchronic ensembles, especially in species with large brains like humans. In order to overcome this limitation, a subset of large-diameter callosal fibers are specialized for fast inter-hemispheric transmission, particularly in large-brained species. Nevertheless, the constraints on fast inter-hemispheric communication in large-brained species can somehow contribute to the development of ipsilateral, intrahemispheric networks, which might promote the development of brain lateralization.
Tipo: Journal article
Palavras-chave: Axon; Brain lateralization; Corpus callosum; Inter-hemispheric transfer; Synchrony; Vision.
Ano: 2003
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000100007

Topography and axon arbor architecture in the visual callosal pathway: effects of deafferentation and blockade of TV-methyl-D-aspartate receptors
Provedor de dados: 48
Autores: OLAVARRÍA,JAIME F; LAING,ROBYN; HIROI,RYOKO; LASIENE,JÚRATE.
Visual callosal fibers link cortical loci in opposite hemispheres that represent the same visual field but whose locations are not mirror-symmetric with respect to the brain midline. Presence of the eyes from postnatal day 4 (P4) to P6 is required for this map to be specified. We tested the hypothesis that specification of the callosal map requires the activation of A'-methyl-D-aspartate receptors (NMDARs). Our results show that blockade of NMDARs with MK-801 during this critical period did not induce obvious abnormalities in callosal connectivity patterns, suggesting that retinal influences do not opérate through NMDAR-mediated processes to specify normal callosal topography. In contrast, we found that interfering with NMDAR function either through...
Tipo: Journal article
Palavras-chave: Corpus callosum; Interhemispheric commissure; Map; NMDAR; Striate cortex.
Ano: 2008
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602008000400007

Regional density of glial cells in the rat corpus callosum
Provedor de dados: 48
Autores: Reyes-Haro,Daniel; Mora-Loyola,Ernesto; Soria-Ortiz,Berenice; García-Colunga,Jesús.
Axons and glial cells are the main components of white matter. The corpus callosum (CC) is the largest white matter tract in mammals; in rodents, 99% of the cells correspond to glia after postnatal day 5 (P5). The area of the CC varies through life and regional differences related to the number of axons have been previously described. Whether glial cell density varies accordingly is unknown; thus the aim of this study was to estimate glial cell density for the genu, body and splenium -the three main regions of CC-, of P6 and P30 rats. Here we report that the density of CC glial cells reduced by ~10% from P6 to P30. Even so, the density of astrocytes showed a slight increase (+6%), probably due to differentiation of glioblasts. Interestingly, glial cell...
Tipo: Journal article
Palavras-chave: Astrocytes; Corpus callosum; Genu; Glial cells; Splenium.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602013000100004

Anatomy of corpus callosum in prenatally malnourished rats
Provedor de dados: 48
Autores: Olivares,Ricardo; Morgan,Carlos; Pérez,Hernán; Hernández,Alejandro; Aboitiz,Francisco; Soto-Moyano,Rubén; Gil,Julio; Ortiz,Alexis; Flores,Osvaldo; Gimeno,Miguel; Laborda,Jesús.
The effect of prenatal malnutrition on the anatomy of the corpus callosum was assessed in adult rats (45-52 days old). In the prenatally malnourished animals we observed a significant reduction of the corpus callosum total area, partial areas, and perimeter, as compared with normal animals. In addition, the splenium of corpus callosum (posterior fifth) showed a significant decrease of fiber diameters in the myelinated fibers without changing density. There was also a significant decrease in diameter and a significant increase in density of unmyelinated fibers. Measurements of perimeter's fractal dimensions from sagittal sections of the brain and corpus callosum did not show significant differences between malnourished and control animals. These findings...
Tipo: Journal article
Palavras-chave: Corpus callosum; Prenatal malnutrition; Rat; Splenium.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602012000100012

Interhemispheric connections between primary visual areas: beyond the midline rule
Provedor de dados: 56
Autores: Houzel,J.-C.; Carvalho,M.L.; Lent,R.
In the last five years, a number of detailed anatomical, electrophysiological, optical imaging and simulation studies performed in a variety of non-human species have revealed that the functional organization of callosal connections between primary visual areas is more elaborate than previously thought. Callosal cell bodies and terminals are clustered in columns whose correspondence to features mapped in the visual cortex, such as orientation and ocularity, are starting to be understood. Callosal connections are not restricted to the vertical midline representation nor do they establish merely point-to-point retinotopic correspondences across the hemispheres, as traditionally believed. In addition, anatomical studies have revealed the existence of an...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Corpus callosum; Visual cortex; Perceptual binding; Vertical midline; Orientation column; Binocular interactions.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001200005

Axonal pathfinding mechanisms at the cortical midline and in the development of the corpus callosum
Provedor de dados: 56
Autores: Richards,L.J.
The corpus callosum is a large fiber tract that connects neurons in the right and left cerebral hemispheres. Agenesis of the corpus callosum (ACC) is associated with a large number of human syndromes but little is known about why ACC occurs. In most cases of ACC, callosal axons are able to grow toward the midline but are unable to cross it, continuing to grow into large swirls of axons known as Probst bundles. This phenotype suggests that in some cases ACC may be due to defects in axonal guidance at the midline. General guidance mechanisms that influence the development of axons include chemoattraction and chemorepulsion, presented by either membrane-bound or diffusible molecules. These molecules are not only expressed by the final target but by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Midline glia; Glial wedge; Glial sling; Indusium griseum glia; Perforating pathway; Corpus callosum.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001200004

Extracellular matrix molecules play diverse roles in the growth and guidance of central nervous system axons
Provedor de dados: 56
Autores: Pires-Neto,M.A.; Braga-de-Souza,S.; Lent,R.
Axon growth and guidance represent complex biological processes in which probably intervene diverse sets of molecular cues that allow for the appropriate wiring of the central nervous system (CNS). The extracellular matrix (ECM) represents a major contributor of molecular signals either diffusible or membrane-bound that may regulate different stages of neural development. Some of the brain ECM molecules form tridimensional structures (tunnels and boundaries) that appear during time- and space-regulated events, possibly playing relevant roles in the control of axon elongation and pathfinding. This short review focuses mainly on the recognized roles played by proteoglycans, laminin, fibronectin and tenascin in axonal development during ontogenesis.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Axon guidance; Development; Anterior commissure; Corpus callosum; Brain.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000500017