The intercentral relations of cortical bioelectrical activity in the human brain after surgical interventions on brain stem formations]

In the process of dynamic study of cortical bioelectrical activity and indices of its intercentral interaction in 52 neurosurgical patients with focal lesion on the brainstem level, the dependence was shown of the CNS reactions to the operative intervention on the character and degree of damage. Variants were described of compensatory neurodynamic reconstructions of electrical processes in observations with transient, stable and irreversible pathological foci of brainstem localization.     

Basic principles of structural asymmetry of cortex formations in the human brain

Studying the cytoarchitectonical asymmetry of human brain cortex requires using the new approaches and modern quantitative methods. One of the promising ways is analyzing relation between the macroscopic and neuronal structure of the brain. The present article contains original data of histological and morphological studies. The authors develop the concept of different degree of expression of asymmetry in the cortex formations of left and right hemispheres. The data on the principal differences of topography and types of structure of fissure and gyrus in different brain hemispheres are presented. Results of the analysis carried out enable one to show the basic criteria of peculiarities of cytoarchitecture of human brain cortex in the left and right hemispheres.     

Functional network organization of the human brain

Real-world complex systems may be mathematically modeled as graphs, revealing properties of the system. Here we study graphs of functional brain organization in healthy adults using resting state functional connectivity MRI. We propose two novel brain-wide graphs, one of 264 putative functional areas, the other a modification of voxelwise networks that eliminates potentially artificial short-distance relationships. These graphs contain many subgraphs in good agreement with known functional brain systems. Other subgraphs lack established functional identities; we suggest possible functional characteristics for these subgraphs. Further, graph measures of the areal network indicate that the default mode subgraph shares network properties with sensory and motor subgraphs: it is internally integrated but isolated from other subgraphs, much like a "processing" system. The modified voxelwise graph also reveals spatial motifs in the patterning of systems across the cortex.     

Development and structure of epithelial formations of the connective tissue stroma of human gingiva

Processes of development and structure of epithelial formations, localized in the connective tissue framework of the gingival mucous membrane have been studied. During the prenatal period of development they are presented as epithelial pearls of Serra, and after birth--as remnants of ++tooth-forming epithelium (RTE). They are remnants of sheaths of the destroyed pearls. The latter, like RTE in the gingival stroma, have a genetic connection with the epithelial islets of Malasser and can cause some diseases in the gingiva.     

Effects of ethomersol on cerebrovascular blood circulation and oxygen metabolism of the brain in acute transient ischemia and recirculation

Intravenous infusion of ethomersol (50 mg/kg during 60 min) decreased cerebral tissue hypoxia at the end of acute cerebral ischemia in cats (30-min occlusion of both carotid and both vertebral arteries). In recirculatory period ethomersol prevented the postischemic hypoperfusion and especially hypo-oxygenation. Ethomersol-induced reduction of Hb-affinity to O2 was demonstrated.     

The circulation,metabolism, and functional activity of the human brain

Special issue dedicated to Dr. Louis Sokoloff.     

Functional differentiation of human brain progenitor cells

Stem cells and progenitor cells derived from the developing human brain have been shown to differentiate into neurons and astrocytes. However, few studies have examined the functional, physiological properties of these differentiated neurons and astrocytes. In this study we have used immunocytochemistry in combination with electrophysiology to examine protein machinery and functional properties of neurons and astrocytes differentiated from human brain progenitor cells (hBPCs).Our results show that serum induces mainly astrocytic phenotype cells that express GFAP and have physiological properties that are typical of astrocytes. hBPCs differentiated with BDNF and PDGF develop mainly into neurons expressing mature neuronal proteins MAP-2, synaptobrevin II and vesicular glutamate transporter I in the process, plus a small population of GFAP-positive radial cells. Based on electrophysiology of BDNF/PDGF-treated cells two classes of cell were identified. Class I cells have functional neuronal properties, including functional voltage-gated Na(+) and K(+) currents, functional AMPA receptors and the ability to generate action potentials. A smaller subpopulation of cells (Class II cells) expresses GFAP and exhibit functional properties of astrocytes, including linear current-voltage relationship and dye-coupling.     

Neural stem cells in the adult human brain

New neurons are continuously generated in certain regions of the adult brain. Studies in rodents have shown that new neurons are generated from self-renewing multipotent neural stem cells. Here we demonstrate that both the lateral ventricle wall and the hippocampus of the adult human brain harbor self-renewing cells capable of generating neurons, astrocytes, and oligodendrocytes in vitro, i.e., bona fide neural stem cells.     

Functional structure of human auditory ossicles.

In a series of 52 auditory ossicles, their structure and functional significance were studied, with special reference to the patterns of force transmission. The significance of the different degrees of cavitation in the ossicles as well as their eventual pathological significance are also discussed.     

Effect of ornid on the regulation of cerebrovascular circulation]

An investigation of ornid, using radioisotopic, electromagnetic and resistographic methods, has shown the drug to diminish cerebral circulation and to abolish completely the constriction of the brain vessels induced by stimulation of the sympathetic and somatic nerves. Ornid prevented the development of experimental disturbances of the cerebral circulation of adrenergic nature.     

Functional annotation of the human brain methylome identifies tissue-specific epigenetic variation across brain and blood

Background

Dynamic changes to the epigenome play a critical role in establishing and maintaining cellular phenotype during differentiation, but little is known about the normal methylomic differences that occur between functionally distinct areas of the brain. We characterized intra- and inter-individual methylomic variation across whole blood and multiple regions of the brain from multiple donors.

Results

Distinct tissue-specific patterns of DNA methylation were identified, with a highly significant over-representation of tissue-specific differentially methylated regions (TS-DMRs) observed at intragenic CpG islands and low CG density promoters. A large proportion of TS-DMRs were located near genes that are differentially expressed across brain regions. TS-DMRs were significantly enriched near genes involved in functional pathways related to neurodevelopment and neuronal differentiation, including BDNF, BMP4, CACNA1A, CACA1AF, EOMES, NGFR, NUMBL, PCDH9, SLIT1, SLITRK1 and SHANK3. Although between-tissue variation in DNA methylation was found to greatly exceed between-individual differences within any one tissue, we found that some inter-individual variation was reflected across brain and blood, indicating that peripheral tissues may have some utility in epidemiological studies of complex neurobiological phenotypes.

Conclusions

This study reinforces the importance of DNA methylation in regulating cellular phenotype across tissues, and highlights genomic patterns of epigenetic variation across functionally distinct regions of the brain, providing a resource for the epigenetics and neuroscience research communities.     

Contents of several amino acids in the cerebellum, brain stem and cerebrum of the 'staggerer', 'weaver' and 'nervous' neurologically mutant mice.

The content of glutamate, GABA, aspartate, glycine and alanine was determined in the cerebellum, brain stem and cerebrum of three different mutant mice which have been named ‘staggerer’, ‘weaver’ and ‘nervous’ on the basis of neurological symptoms. In the ‘staggerer’ and ‘weaver’ mutants there is an almost complete absence of granule cells in the cerebellar cortex while in the ‘nervous’ mutant there is a loss of Purkinje cells (and to a lesser extent a loss of granule cells) in the cerebellar cortex. In the cerebellum of the ‘weaver’ mutant, the content of glutamate was signficantly lower (P < 0.025) than control values (8.77 ± 0.76 vs 12.0 ± 1.3 μmol/g tissue wet wt) and the contents of GABA and glycine were significantly greater than normal levels. In the cerebellum of the ‘staggerer’ mutant, the content of glutamate was significantly lower (6.62 ± 0.70 μmol/g) and the contents of glycine and alanine significantly higher than control values. In the cerebrum and brain stem regions of the staggerer mutant, weaver mutant and the normals the contents of the five amino acids were the same. The contents of glycine and alanine in the cerebellum, GARA and glycine in the brain stem and GABA and alanine in the cerebrum of the nervous mutants were higher than control values. The data are discussed in terms of a possible role for glutamate functioning as an excitatory transmitter when released from the cerebellar granule cells.