SEARCH · Search PubMed

Results for “brain structure”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

PubMed1977

[Insufficient excitation for speech in focal lesions of non-specific brain structures].

On the basis of a study of 150 patients with focal lesions of the mesencephalo-diencephalic brain areas the authors discuss speech disorders, appearing due to disturbances in the functions of the activating nonspecific systems. They indicate that these speech disorders are conditioned by an insufficiency of speech volition. However, in communicative important situations for the patient they can be overcome. In development of mesencephalodiencephalic pathology the syndrome of insufficient speech volition may be transmitted into a clinical picture of akinetic mutism. The problem of differentiation of insufficiency speech volition is being discussed in relation to lesions on different levels of the activizing nonspecific system and the accompanying drop of speech activity of the motor-aphatic and disarthric disorders.

Adult↗

PubMedDate not supplied

[The development of attention, memory and the inhibitory processes: the chronological relation with the maturation of brain structure and functioning].

Development during childhood and adolescence is characterized by greater efficiency in performing cognitive tasks. The correlations between cognitive and brain development are not altogether clear and have not been studied in depth. The aim of this study is to survey the research carried out into the development of cognitive functioning in children, adolescents and adults, and its chronological relation with brain development. Anatomofunctional and cognitive-behavioural studies are presented. Anatomical studies have shown that the white matter increases linearly throughout childhood and adolescence, whereas cortical and subcortical grey matter increases in the pre-adolescent period and later diminishes in the post adolescent stage. It has been claimed that these changes are regional and that the prefrontal cortex (PFC) is one of the last areas to mature. Functional research has studied cognitive processes attributed to the functioning of the PFC, such as attention, working memory and the inhibition of irrelevant responses. The findings from these studies have shown a behavioural and physiological development of these three processes during childhood and adolescence. Behavioural results have evidenced greater efficiency in capacities such as discriminating between relevant and irrelevant information, storing and handling information in the memory and the inhibition of unsuitable responses during the performance of a task. The physiological results have presented changes in the magnitude, spread and integration of the regions activated during task performance. Cognitive and behavioural maturation is consecutive to structural and physiological maturing and this is produced in a chronologically and qualitatively different way in the distinct regions of the brain.

Attention↗

PubMed1995

Differentiation of normal and pathologic brain structures in MRI using exact T1 and T2 values followed by a multidimensional cluster analysis.

A new method to differentiate and classify normal and pathologic brain tissue in Magnetic Resonance Imaging (MRI) is introduced. With a special pulse sequence, exact T1 and T2 values are simultaneously acquired, where the T2 values may show a biexponential decay behavior. The automatic segmentation of the tissue is based on a histogram analysis of the multidimensional parameters. The tissue-characterizing parameters are stored in a database, which serves as an objective classification of different tissues. A pilot study with 15 healthy volunteers and 100 patients showed a good differentiation between normal tissue like white and gray matter, cerebrospinal fluid, muscle, and fat, thereby revealing a biexponential decay behavior of fat. Pathologic tissue-like edema and meningioma could be classified with high accuracy, while glioblastoma or astrocytoma were difficult to classify because of their non-homogeneous structures.

Adipose Tissue↗

PubMed1984

Comparison of brain structure volumes in insectivora and primates. V. Area striata (AS).

Volumes of the area striata (area 17, Brodmann) were measured in 44 species of Primates and Scandentia and some of its laminar components in 25 species. The relative size (expressed by size indices) is on the average distinctly larger in simians than in isoponderous prosimians. The average dimensions of increase are 2.5 times for total area striata (ASV), 3.4 times for white matter (ASW), 2.35 times for grey matter (ASG), 1.9 times for lamina 1 (ASG 1) and 2.4 times for laminae 2-6 (ASG 2-6). The high increase of the white matter and the low increase of lamina 1 both correspond to similar results on the total neocortex (Frahm et al., 1982). The molecular layer (ASG 1) is on the average about 12% of the total area striata grey (ASG). The visual cortex thus has a narrower molecular layer than the neocortex as a whole, in which an average of 14% was found. The size indices of man are within the simian range and generally slightly above the simian average. Tree shrews have relatively small visual cortices, but reach into the lower part of the prosimian range. For Insectivora, ASG volumes were estimated from CGL volumes. According to these estimates, the relative ASG size is about 1/90 in shrews, about 1/40 in tenrecs and about 1/10 in hedgehogs that of isoponderous prosimians. In the European hedgehog, the area striata is about 12% of the total neocortex, a value similarly to that found in area measurements by Brodmann (1913). The relative size of the area striata is discussed with regard to functional, ecoethological and phylogenetic considerations. With increasing body weight, the increase in the visual structures, both cortical and non-cortical, is weak when compared with other brain parts and body organs (strongly negative allometry).

Animals↗

PubMed2006