scholarly journals Encephalometry on the medial face of the human brain hemisphere: a necropsy study

2005 ◽  
Vol 63 (2b) ◽  
pp. 430-436 ◽  
Author(s):  
Paula J. Ribeiro ◽  
Serafim V. Cricenti V. ◽  
Carmen L.P. Lancellotti
Keyword(s):  
Corpus Callosum ◽  
Human Brain ◽  
Frontal Cortex ◽  
Anterior Part ◽  
Average Distance ◽  
Posterior Part ◽  
Cerebral Hemispheres ◽  
Frontal Pole ◽  
Occipital Pole ◽  
The Right

This study aims to evaluate the dimensions of the human brain, specifically in the frontal cortex, helping the analysis of neuroimaging. A form was made to register and describe encephalic measurements and 81 cerebral hemispheres (CH) were analyzed. Male individuals showed larger CH length; wider superior frontal gyrus in the right CH; bigger encephalic weight and corpus callosum (CC) width. The proportion of measurement from the frontal pole to the most anterior part of the CC genu, related to the CH length gets smaller with aging, whereas the average distance from the most posterior part of the splenum of the CC to the occipital pole was bigger in both male CHs and there was a tendency of decrease in this difference with aging.

Analysis of 3D Corpus Callosum Images in the Brains of Autistic Individuals

2016 ◽  
pp. 159-184
Author(s):  
Ahmed Elnakib ◽  
Manuel F. Casanova ◽  
Ahmed Soliman ◽  
Georgy Gimel'farb ◽  
Ayman El-Baz
Keyword(s):  
Autism Spectrum Disorder ◽  
Corpus Callosum ◽  
Human Brain ◽  
Shape Analysis ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Cerebral Hemispheres ◽  
Higher Cognitive Functions ◽  
The Right ◽  
Abnormal Anatomy

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is characterized by abnormalities in behavior and higher cognitive functions. The corpus callosum (CC) is the largest fiber bundle that connects the left and the right cerebral hemispheres of the human brain. Several studies have revealed an abnormal anatomy of the CC in the brains of autistic individuals that associates this neurodevelopmental condition with impaired communication between the hemispheres. In this chapter, we develop a framework to analyze the CC of autistic individuals in order to provide a diagnostic tool for autism. The key advantage of this approach is the development of a cylindrical mapping that offers simplified coordinates for comparing the brains of autistic individuals and neurotypicals. Experimental results showed significant differences (at the 95% confidence level) between 17 normal and 17 autistic subjects in four anatomical divisions, i.e. splenium, rostrum, genu, and body of their CCs. Moreover, the initial centerline-based shape analysis of the CC documented a promising supplement to the current techniques for diagnosing autism.

Analysis of 3D Corpus Callosum Images in the Brains of Autistic Individuals

2016 ◽  
pp. 1529-1554
Author(s):  
Ahmed Elnakib ◽  
Manuel F. Casanova ◽  
Ahmed Soliman ◽  
Georgy Gimel'farb ◽  
Ayman El-Baz
Keyword(s):  
Autism Spectrum Disorder ◽  
Corpus Callosum ◽  
Human Brain ◽  
Shape Analysis ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Cerebral Hemispheres ◽  
Higher Cognitive Functions ◽  
The Right ◽  
Abnormal Anatomy

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is characterized by abnormalities in behavior and higher cognitive functions. The corpus callosum (CC) is the largest fiber bundle that connects the left and the right cerebral hemispheres of the human brain. Several studies have revealed an abnormal anatomy of the CC in the brains of autistic individuals that associates this neurodevelopmental condition with impaired communication between the hemispheres. In this chapter, we develop a framework to analyze the CC of autistic individuals in order to provide a diagnostic tool for autism. The key advantage of this approach is the development of a cylindrical mapping that offers simplified coordinates for comparing the brains of autistic individuals and neurotypicals. Experimental results showed significant differences (at the 95% confidence level) between 17 normal and 17 autistic subjects in four anatomical divisions, i.e. splenium, rostrum, genu, and body of their CCs. Moreover, the initial centerline-based shape analysis of the CC documented a promising supplement to the current techniques for diagnosing autism.

scholarly journals Human brain harbors single nucleotide somatic variations in functionally relevant genes possibly mediated by oxidative stress

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2520 ◽  
Author(s):  
Anchal Sharma ◽  
Asgar Hussain Ansari ◽  
Renu Kumari ◽  
Rajesh Pandey ◽  
Rakhshinda Rehman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Corpus Callosum ◽  
Human Brain ◽  
Frontal Cortex ◽  
Oxidative Stress Marker ◽  
Somatic Variation ◽  
Single Nucleotide ◽  
Normal Human Brain ◽  
Normal Human ◽  
The Brain

Somatic variation in DNA can cause cells to deviate from the preordained genomic path in both disease and healthy conditions. Here, using exome sequencing of paired tissue samples, we show that the normal human brain harbors somatic single base variations measuring up to 0.48% of the total variations. Interestingly, about 64% of these somatic variations in the brain are expected to lead to non-synonymous changes, and as much as 87% of these represent G:C>T:A transversion events. Further, the transversion events in the brain were mostly found in the frontal cortex, whereas the corpus callosum from the same individuals harbors the reference genotype. We found a significantly higher amount of 8-OHdG (oxidative stress marker) in the frontal cortex compared to the corpus callosum of the same subjects (p<0.01), correlating with the higher G:C>T:A transversions in the cortex. We found significant enrichment for axon guidance and related pathways for genes harbouring somatic variations. This could represent either a directed selection of genetic variations in these pathways or increased susceptibility of some loci towards oxidative stress. This study highlights that oxidative stress possibly influence single nucleotide somatic variations in normal human brain.

III. On the commissures of the cerebral hemispheres of the marsupialia and monotremata, as compared with those of the placental mammals

1865 ◽  
Vol 14 ◽  
pp. 71-74 ◽  
Keyword(s):  
Corpus Callosum ◽  
Human Brain ◽  
Human Body ◽  
Short Description ◽  
Cerebral Hemispheres ◽  
Middle Line ◽  
Short Space ◽  
Mutual Relations ◽  
Superior Margin

As it is most convenient to pass from the best to the least known, and especially as the terms used in describing the anatomy of the vertebrated animals have in most cases been originally bestowed upon parts of the human body, the Paper commences by a short description of the septum ventriculorum and commissures of the human brain. This is done with a view to establish clearly, both by their structure and development, the mutual relations of the great transverse commissure or corpus callosum and the fornix. The latter is defined as essentially a longitudinal commissure, consisting of two lateral halves closely applied for a short space in the middle line, but each half belonging to its own hemisphere, and formed out of the longitudinal fibres bordering the superior margin of the ventricular aperture.

Morphological differences in the commissural connections of the forebrain in white outbred mice and BALB/C mice

2021 ◽  
Vol 21 (2) ◽  
pp. 99-105
Author(s):  
Inessa V. Karpova ◽  
Nikita A. Popkovsky ◽  
Sergey N. Proshin ◽  
Evgeny R. Bychkov ◽  
Ilia Y. Tissen ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Anterior Commissure ◽  
Anterior Part ◽  
Intraspecific Interactions ◽  
Morphological Basis ◽  
Outbred Mice ◽  
Left Section ◽  
The Right

BACKGROUND: The study of the mechanisms of interaction of paired structures of the mammalian brain is a fundamental problem of modern neuroscience, which is of great applied importance. Even mild underdevelopment of the corpus callosum in humans can lead to autism. It is known that the intensity of intraspecific interactions in BALB/c mice is lower than in white outbred ones, while some BALB/c substrains are characterized by underdevelopment of the corpus callosum. AIM: To compare the morphological parameters of the large brain commissures in white outbred mice and BALB/c mice grown in the Rappolovo nursery (Leningrad region). MATERIALS AND METHODS: The morphology of the corpus callosum was studied in 13 male white outbred mice and 7 male BALB/c mice at the age of 8 months. RESULTS: In mice of both subpopulations, the area of the anterior commissure of the left hemisphere was smaller than that of the right hemisphere (p 0.05). There were no differences between subpopulations in this parameter. The area of the left section of the corpus callosum trunkus in outbred mice was larger than the right one (p 0.001), while in BALB/c mice the areas of the left and right slices did not differ. Despite the absence of significant differences in the area of the anterior part (rostrum et genu) of the corpus callosum the density of the location of oligodendrocytes in this brain structure in the mice of the two subpopulations was different. The number of oligodendrocytes in 0.01 mm2 on the left section of the anterior part of the corpus callosum in BALB/c mice was greater than in white outbred mice (p 0.05). A similar trend was revealed when comparing slices of the right hemisphere (p = 0.065). CONCLUSIONS: The large area of the right parasagittal slice of the anterior commissure suggests that some of its constituent fibers do not cross the midline, but end within the same hemisphere, which may be the morphological basis for the functional dominance of the temporal cortex of the left hemisphere in mice of both subpopulations. The corpus callosum in BALB/c mice is developed symmetrically, and in white outbred ones asymmetrically. This feature may be the morphological basis for the functional dominance of the parietal cortex of the right hemisphere in outbred animals.

scholarly journals Splenium of Corpus Callosum: Patterns of Interhemispheric Interaction in Children and Adults

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Maria G. Knyazeva
Keyword(s):  
Corpus Callosum ◽  
Striate Cortex ◽  
Anterior Part ◽  
Human Life ◽  
Posterior Part ◽  
Structural Mri ◽  
Oscillatory Activity ◽  
Visual Hierarchy ◽  
Inhibitory Circuitry ◽  
Extrastriate Areas

The splenium of the corpus callosum connects the posterior cortices with fibers varying in size from thin late-myelinating axons in the anterior part, predominantly connecting parietal and temporal areas, to thick early-myelinating fibers in the posterior part, linking primary and secondary visual areas. In the adult human brain, the function of the splenium in a given area is defined by the specialization of the area and implemented via excitation and/or suppression of the contralateral homotopic and heterotopic areas at the same or different level of visual hierarchy. These mechanisms are facilitated by interhemispheric synchronization of oscillatory activity, also supported by the splenium. In postnatal ontogenesis, structural MRI reveals a protracted formation of the splenium during the first two decades of human life. In doing so, the slow myelination of the splenium correlates with the formation of interhemispheric excitatory influences in the extrastriate areas and the EEG synchronization, while the gradual increase of inhibitory effects in the striate cortex is linked to the local inhibitory circuitry. Reshaping interactions between interhemispherically distributed networks under various perceptual contexts allows sparsification of responses to superfluous information from the visual environment, leading to a reduction of metabolic and structural redundancy in a child's brain.

Self-Consciousness and "Split" Brains

2018 ◽  
Author(s):  
Elizabeth Schechter
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Corpus Callosum ◽  
Human Brain ◽  
The United States ◽  
The Other ◽  
Cerebral Hemispheres ◽  
Experimental Conditions ◽  
Fiber Tract ◽  
Split Brain

The largest fiber tract in the human brain is the corpus callosum, which connects the two cerebral hemispheres. A number of surgeries severing this structure were performed on adults in the United States in the second half of the twentieth century. After they are surgically separated from each other in this way, a “split-brain” subject’s hemispheres begin to operate unusually independently of each other in the realms of perception, cognition, and the control of action—almost as if each had a mind of its own. But can a mere hemisphere really see? Speak? Feel? Know what it has done? The split-brain cases raise questions of psychological identity: How many subjects of experience are there within a split-brain subject? How many persons? How many minds? Under experimental conditions, split-brain subjects often act as though they were animated by two distinct conscious beings, evoking the duality intuition. On the other hand, a split-brain subject seems like one of us—not like two of us sharing one body. Split-brain subjects thus also evoke the unity intuition.This book is devoted to reconciling these two apparently opposing intuitions. The key to doing so are facts about the way self-consciousness operates in split-brain subjects. A split-brain subject is composed of two conscious psychological beings that fail to recognize each other’s existence and indeed cannot distinguish themselves from each other. Instead, each must first-personally identify with the split-brain subject as a whole, and in so doing, the two make themselves into one person.

scholarly journals 3. On a Case of Absence of the Corpus Callosum in the Human Brain

1889 ◽  
Vol 15 ◽  
pp. 320-341 ◽  
Author(s):  
Alexander Bruce
Keyword(s):  
Corpus Callosum ◽  
Human Brain ◽  
Cerebral Hemispheres

Cases of absence or defect of the corpus callosum are of interest not only because of their great rarity, but because of the light which they throw on the distribution and functions of this commissure, and on the development of the mesial aspects of the cerebral hemispheres.

scholarly journals Case Report: Corpus callosal apraxia following acute ischemic stroke

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 731
Author(s):  
Santhosh Narayanan ◽  
Gomathy Subramaniam
Keyword(s):  
Computed Tomography ◽  
Ischemic Stroke ◽  
Case Report ◽  
Corpus Callosum ◽  
The Body ◽  
Cerebral Hemispheres ◽  
Diagnostic Challenge ◽  
Compact Structure ◽  
Ischemic Infarct ◽  
The Right

The corpus callosum is a compact structure that connects the right and left cerebral hemispheres. Here we report the case of a 50 year old woman who presented with features of corpus callosum apraxia, initially mistaken as psychiatric symptom by her relatives. Computed tomography and magnetic resonance of brain confirmed the diagnosis of acute ischemic infarct in the body of the corpus callosum. Isolated stroke involving the corpus callosum is rarely reported in literature and is a diagnostic challenge due to atypical clinical features.

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