scholarly journals К. Schaffer: Zur feineren Struktur der Hirnrinde und über funktionelle Bedeutung der Nervenzellenfortsätze. Arch. f. Mikrosk. Anatomie. XLVIIL 4 Heft. 1897. S. S. 550—572

2020 ◽  
Vol V (3) ◽  
pp. 167-169
Author(s):  
A. E. Smirnov
Keyword(s):  
Cerebral Cortex ◽  
Opposite Direction ◽  
Molecular Layer ◽  
Pyramidal Cells ◽  
Special Group ◽  
The Brain ◽  
Axial Cylinder

The author's research refers to the anterior cerebral cortex of a newborn dog. The author studies in detail the so-called tiny pyramidal cells, lying between the pluripolar cells of the molecular layer and the small (true) pyramidal cells. Already R. y Cajal drew attention to polygonal or core-shaped cells, the cells that lie behind the layer of the outermost cells (pluripolare Nervenzellen von R. y Cajal), but did not separate them into a special group, believing that these cells were gradually changing vid, go into the small pyramids, to which he numbered them. Schaffer separates these cells into a special group, calling it the layer of surface polymorphic cells. These cells have a dark variety of shapes (fusiform, oval, roundish, pear-shaped, polygonal) and lie in approximately four (4) rows. Dendrites go then, mainly, in two opposite directions (for fusiform cells), then they move radially in all directions (for round and polygonal cells). The number of dendrites is sometimes strikingly abundant. Dendrites going to the surface of the brain reach it, while dendrites of the opposite direction sometimes go down to the ammonium formations of the cerebral cortex. Special attention should be paid to the axial cylinder of the disassembled cells; on the basis of the features of this appendix, the author distinguishes 3 types of disassembled cells.

A unitary hypothesis of mind-brain interaction in the cerebral cortex

1990 ◽  
Vol 240 (1299) ◽  
pp. 433-451 ◽  
Keyword(s):  
Cerebral Cortex ◽  
Pyramidal Cells ◽  
Neuronal Structure ◽  
Mental Experience ◽  
Effective Selection ◽  
Global Nature ◽  
The Mind ◽  
Mental Events ◽  
Apical Dendrites ◽  
The Brain

A brief introduction to the brain-mind problem leads on to a survey of the neuronal structure of the cerebral cortex. It is proposed that the basic receptive units are the bundles or clusters of apical dendrites of the pyramidal cells of laminae V and III-II as described by Fleischhauer and Peters and their associates. There are up to 100 apical dendrites in these receptive units, named dendrons. Each dendron would have an input of up to 100000 spine synapses. There are about 40 million dendrons in the human cerebral cortex. A study of the influence of mental events on the brain leads to the hypothesis that all mental events, the whole of the World 2 of Popper, are composed of mental units, each carrying its own characteristic mental experience. It is further proposed that each mental unit, named psychon, is uniquely linked to a dendron. So the mind-brain problem reduces to the interaction between a dendron and its psychon for all the 40 million linked units. In my 1986 paper ( Proc. R. Soc. Lond . B 227, 411-428) on the mind-brain problem, there was developed the concept that the operation of the synaptic microsites involved displacement of particles so small that they were within range of the uncertainty principle of Heisenberg. The psychon-dendron interaction provides a much improved basis for effective selection by a process analogous to a quantal probability field. In the fully developed hypothesis psychons act on dendrons in the whole world of conscious experiences and dendrons act on psychons in all perceptions and memories. It is shown how these interactions involve no violation of the conservation laws. There are great potentialities of these unitary concepts, for example as an explanation of the global nature of a visual experience from moment to moment. It would seem that there can be psychons not linked to dendrons, but only to other psychons, creating what we may call a psychon world.

scholarly journals Iron Deposition in the Brain Following the Ischemia in a Rat Model of Ischemic Tolerance

2004 ◽  
Vol 47 (4) ◽  
pp. 285-288 ◽  
Author(s):  
Viera Danielisová ◽  
Miroslava Némethová ◽  
Jozef Burda
Keyword(s):  
Cerebral Cortex ◽  
Frontal Cortex ◽  
Rat Model ◽  
Pyramidal Neurons ◽  
Pyramidal Cells ◽  
Ischemic Tolerance ◽  
Iron Deposition ◽  
Sham Operation ◽  
Vessel Occlusion ◽  
The Brain

Preconditioning of the brain by short-term ischemia increases brain tolerance to the subsequent severer ischemia. In this study, we investigated iron deposition in the cerebral cortex and the ischemic tolerance in a rat model of cerebral ischemia. Forebrain ischemia was induced by four-vessel occlusion for 5 min as ischemic preconditioning. Two days after preconditioning or after the sham-operation, the second ischemia was induced for 20 min. Changes in the cerebral cortex were examined after 1 to 8 weeks of recirculation following 20 min ischemia with or without preconditioning using the iron histochemistry. Granular deposits of the iron were found in the cytoplasm of the pyramidal cells in the layers III and V of the frontal cortex after 1 week of recirculation. When the rats were exposed to 5 min ischemia 2 days before 20 min lasting ischemia, the deposition of iron in the cytoplasm of the pyramidal cells in layers III and V of the frontal cortex was significantly lower during all periods of reperfusion. Preconditioning 5 min ischemia followed by 2 days of reperfusion before 20 min ischemia also prevented degeneration of the pyramidal neurons in layers III and V of the frontal cortex.

scholarly journals Analysis of Histological Features of the Cerebral Cortex and Hippocampus of Albino Rats Using Haematoxylin & Eosin Stain- An Observational Study

2021 ◽  
pp. 53-64
Author(s):  
M. V. Shreejha ◽  
R. Priyadharshini ◽  
Palati Sinduja ◽  
V. Meghashree
Keyword(s):  
Cerebral Cortex ◽  
Observational Study ◽  
Rat Brain ◽  
Granular Layer ◽  
Molecular Layer ◽  
Pyramidal Cells ◽  
Stratum Radiatum ◽  
Albino Rats ◽  
Histological Features ◽  
Pyramidal Layer

Background: The study determined the histological layers of the cerebral cortex and hippocampus of the albino rat brain samples has been used in the study. The Cerebral cortex is composed of the Molecular layer, external granular, external pyramidal layer, internal granular layer and interior pyramidal layer. The layers of the hippocampus are alveus, stratum oriens, stratum pyramidale, stratum radiatum, stratum lacunosum and stratum moleculare. The aim of the study is to analyze the detailed histological features of the cerebral cortex and hippocampus layers of albino rats at the magnification of 10X,100X,40X. By using haematoxylin and eosin stain as an observational study. Materials and Methods: The samples were preserved and fixed with the formalin and stained by haematoxylin and eosin and observed with a light microscope. Results: The molecular layer is the superficial layer containing neurons. The outer granular layer of the cells are densely packed. Outer pyramidal layer contains rich pyramidal cells, Inner granular layer contains stellate cells, Inner pyramidal layer contains glial cells and the deeper multiform layer is composed of pyramidal cells. The hippocampus contains three layers of cornu Ammonia CA1, CA2, CA3. CA1 responds to memory and is covered by the choroid plexus. CA2 contains 3 major cell dentate gyrus, pyramidal cells, pyramidal neurons and CA3 composed of stratum lucidum. Conclusion: The study of brain analysis of histological features of the cerebral cortex and hippocampus of the brain adds a greater insight in understanding the histology of various types of layers in rat brain and morphology of brain cells.

Cytoarchitecture and thalamic connectivity of third somatosensory area of cat cerebral cortex

1978 ◽  
Vol 41 (2) ◽  
pp. 268-284 ◽  
Author(s):  
D. G. Tanji ◽  
S. P. Wise ◽  
R. W. Dykes ◽  
E. G. Jones
Keyword(s):  
Cerebral Cortex ◽  
Pyramidal Cells ◽  
Thalamic Nuclei ◽  
Somatosensory Area ◽  
Posterior Group ◽  
Layer V ◽  
Evoked Activity ◽  
To Receive ◽  
The Brain ◽  
Cat Cerebral Cortex

1. The third somatosensory area (SIII) was identified in the cat cerebral cortex by the recording of surface potentials evoked by deflection of a single contralateral mystacial vibrissa. A small amount of tritiated leucine was then injected at the center of the focus of evoked activity and, after a suitable survival period, the brain was prepared for autoradiography. 2. As defined by the presence of an autoradiographic injection, the SIII focus lay in a cytoarchitectonic field characterized in particular by the presence of very large pyramidal cells in layer V and corresponding to area 5a of Hassler and Muhs-Clement (24). 3. The terminal ramifications of corticothalamic cells, as outlined by axoplasmically transported label, formed clustered aggregations in the medial division of the posterior group of thalamic nuclei (Pom) and not in the ventrobasal complex (VB). This part of Pom is known to receive fibers from the spinal cord. 4. Injections of horseradish peroxidase primarily affecting area 5a retrogradely labeled cells in Pom but not in VB. 5. Injections of isotope in the two other foci of vibrissa-evoked activity usually recorded in each brain were invariably found to label a part of area 3b of the first somatosensory area (SI) in the case of the more anterior focus. The second focus sometimes lay in area 2 of SI and sometimes in the second somatosensory area (SII).

scholarly journals SPREAD OF DIRECTLY EVOKED RESPONSES IN THE CAT'S CEREBRAL CORTEX

1959 ◽  
Vol 42 (4) ◽  
pp. 761-777 ◽  
Author(s):  
V. B. Brooks ◽  
P. S. Enger
Keyword(s):  
Cerebral Cortex ◽  
Pyramidal Cells ◽  
Neuromuscular Blocking ◽  
Brain Circulation ◽  
Direct Stimulation ◽  
Synaptic Excitation ◽  
Excitatory State ◽  
Supramaximal Stimulation ◽  
The Brain ◽  
Stimulation Of

A study has been made of the electrical responses to direct stimulation of the exposed cerebral cortex of cats that had been immobilized with neuromuscular blocking drugs, and whose muscle and skin wounds had been locally anesthetized. The characteristics and spread of the first and second surface-negative responses are described. It was found that the first surface-negative response to weak stimuli decays linearly to zero at 3 to 6 mm. from the point of stimulation. Intermediate stimuli cause farther and non-linear spread: responses are re-initiated, or reinforced, at 6 to 10 mm.; and supramaximal stimulation produces reinforcement both at 5 and at 10 mm. The conduction velocity of these responses is uniform for linear spread (0.7 to 2.0 m./sec.), but reinforced responses occur 1 to 3 msec. earlier than would be expected for simple conduction. The phenomenon of re-initiation, or reinforcement, depends upon the excitatory state of the brain; circulation and previous stimulation are important factors. Connections outside the gyrus matter only in so far as they provide other sources of general excitation. It is concluded that two types of transmission: slow and fast, can lead to generation of similar surface-negative responses. The suggestion is made that the slowly conducted surface-negative potentials are due to direct or to synaptic excitation of pyramidal cells; while the responses with shortened latency are initiated synaptically on other pyramidal cells after fast conduction at about 10 m./sec. in tangential fibres.

Glucuronyl 3-sulfate occurs exclusively on distal unmyelinated terminals of selected sensory neurons in the peripheral nervous system

1995 ◽  
Vol 53 ◽  
pp. 958-959
Author(s):  
S.S. Spicer ◽  
B.A. Schulte
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Peripheral Nervous System ◽  
Sensory Neurons ◽  
Sensory Nerves ◽  
Tissue Antigens ◽  
The Central Nervous System ◽  
The Brain ◽  
Leu 7

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.

Neurotransmitter systems of female mouse brain during growth of malignant melanoma modeled on the background of chronic pain

2018 ◽  
pp. 49-55
Author(s):  
О.И. Кит ◽  
И.М. Котиева ◽  
Е.М. Франциянц ◽  
И.В. Каплиева ◽  
Л.К. Трепитаки ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Cerebral Cortex ◽  
Malignant Melanoma ◽  
Sciatic Nerve ◽  
Female Mouse ◽  
Combined Effects ◽  
Malignant Growth ◽  
Course Of Disease ◽  
The Brain ◽  
Melanoma Growth

Известно, что биогенные амины (БА) участвуют в злокачественном росте, их уровень изменяется в ЦНС при болевом воздействии, однако исследований о сочетанном влиянии хронической боли (ХБ) и онкопатологии на динамику БА в головном мозге не проводилось. Цель: изучить особенности баланса БА в коре головного мозга в динамике роста меланомы, воспроизведенной на фоне ХБ. Материалы и методы. Работа выполнена на 64 мышах-самках, весом 21-22 г. Животным основной группы меланому В16/F10 перевивали под кожу спины через 2 недели после перевязки седалищных нервов. Группой сравнения служили мыши с меланомой без боли. Уровни БА: адреналина, норадреналина, дофамина (ДА), серотонина (5-НТ), гистамина, а также 5-ОИУК определяли методом иммуноферментного анализа. Результаты. У мышей с ХБ уменьшается содержание большинства БА, однако уровень ДА не изменяется. Метаболизм 5-НТ происходит с участием МАО. Развитие меланомы сопровождается увеличением содержания ДА и 5-НТ, тогда как МАО - ингибируется. Направленность сдвигов БА при развитии меланомы на фоне ХБ оказалась практически такой же, как и без неё. В то же время ХБ ограничивает накопление 5-НТ в коре мозга при меланоме, что сопровождается более агрессивным её течением. Выводы. ХБ ограничивает включение стресс-лимитирующих механизмов в головном мозге при развитии меланомы у мышей, что приводит к более агрессивному течению злокачественного процесса. Biogenic amines (BA) are known to be involved in malignant growth, and their CNS levels change in pain; however, there are no studies of combined effects of chronic pain (CP) and cancer on BA dynamics in the brain. Aim: To study features of BA balance in the cerebral cortex during melanoma growth associated with CP. Material and methods. The study included 64 female mice weighing 21-22 g. In the main groups, B16/F10 melanoma was transplanted under the skin of the back two weeks following sciatic nerve ligation. Mice with melanoma without pain were used as the control. Concentrations of BA: adrenaline, noradrenaline, dopamine (DA), serotonin (5-HT), histamine and 5-HIAA were measured with ELISA. Results. Concentrations of BAs decreased in mice with CP although DA levels did not change. 5-HT metabolism involved MAO. The development of melanoma was accompanied by increases in DA and 5-HT whereas MAO was inhibited. The direction of BA changes during the development of melanoma was the same with and without CP. At the same time, CP with melanoma limited accumulation of 5-HT in the cerebral cortex, which resulted in even more aggressive course of cancer. Conclusion. CP restricted the activation of cerebral stress-limiting mechanisms during the development of melanoma in mice, which resulted in a more aggressive course of disease.

scholarly journals Long-Term Glucose Starvation Induces Inflammatory Responses and Phenotype Switch in Primary Cortical Rat Astrocytes

2021 ◽  
Author(s):  
Vanessa Kogel ◽  
Stefanie Trinh ◽  
Natalie Gasterich ◽  
Cordian Beyer ◽  
Jochen Seitz
Keyword(s):  
Cerebral Cortex ◽  
Synapse Formation ◽  
Inflammatory Responses ◽  
Glucose Starvation ◽  
Unfolded Protein ◽  
Genes Encoding ◽  
Phenotype Switch ◽  
The Unfolded Protein Response ◽  
The Brain

AbstractAstrocytes are the most abundant cell type in the brain and crucial to ensure the metabolic supply of neurons and their synapse formation. Overnutrition as present in patients suffering from obesity causes astrogliosis in the hypothalamus. Other diseases accompanied by malnutrition appear to have an impact on the brain and astrocyte function. In the eating disorder anorexia nervosa (AN), patients suffer from undernutrition and develop volume reductions of the cerebral cortex, associated with reduced astrocyte proliferation and cell count. Although an effect on astrocytes and their function has already been shown for overnutrition, their role in long-term undernutrition remains unclear. The present study used primary rat cerebral cortex astrocytes to investigate their response to chronic glucose starvation. Cells were grown with a medium containing a reduced glucose concentration (2 mM) for 15 days. Long-term glucose starvation increased the expression of a subset of pro-inflammatory genes and shifted the primary astrocyte population to the pro-inflammatory A1-like phenotype. Moreover, genes encoding for proteins involved in the unfolded protein response were elevated. Our findings demonstrate that astrocytes under chronic glucose starvation respond with an inflammatory reaction. With respect to the multiple functions of astrocytes, an association between elevated inflammatory responses due to chronic starvation and alterations found in the brain of patients suffering from undernutrition seems possible.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

Dream Bizarreness as the Cognitive Correlate of Altered Neuronal Behavior in REM Sleep

1989 ◽  
Vol 1 (3) ◽  
pp. 201-222 ◽  
Author(s):  
Adam N. Mamelak ◽  
J. Allan Hobson
Keyword(s):  
Neural Networks ◽  
Cerebral Cortex ◽  
Rem Sleep ◽  
Neuronal Dynamics ◽  
Neurophysiological Model ◽  
The Relationship ◽  
Cognitive Feature ◽  
The Brain ◽  
Cognitive Correlate ◽  
Raphe Neurons

Bizarreness is a cognitive feature common to REM sleep dreams, which can be easily measured. Because bizarreness is highly specific to dreaming, we propose that it is most likely brought about by changes in neuronal activity that are specific to REM sleep. At the level of the dream plot, bizarreness can be defined as either discontinuity or incongruity. In addition, the dreamer's thoughts about the plot may be logically deficient. We propose that dream bizarreness is the cognitive concomitant of two kinds of changes in neuronal dynamics during REM sleep. One is the disinhibition of forebrain networks caused by the withdrawal of the modulatory influences of norepinephrine (NE) and serotonin (5HT) in REM sleep, secondary to cessation of firing of locus coeruleus and dorsal raphe neurons. This aminergic demodulation can be mathematically modeled as a shift toward increased error at the outputs from neural networks, and these errors might be represented cognitively as incongruities and/or discontinuities. We also consider the possibility that discontinuities are the cognitive concomitant of sudden bifurcations or “jumps” in the responses of forebrain neuronal networks. These bifurcations are caused by phasic discharge of pontogeniculooccipital (PGO) neurons during REM sleep, providing a source of cholinergic modulation to the forebrain which could evoke unpredictable network responses. When phasic PGO activity stops, the resultant activity in the brain may be wholly unrelated to patterns of activity dominant before such phasic stimulation began. Mathematically such sudden shifts from one pattern of activity to a second, unrelated one is called a bifurcation. We propose that the neuronal bifurcations brought about by PGO activity might be represented cognitively as bizarre discontinuities of dream plot. We regard these proposals as preliminary attempts to model the relationship between dream cognition and REM sleep neurophysiology. This neurophysiological model of dream bizarreness may also prove useful in understanding the contributions of REM sleep to the developmental and experiential plasticity of the cerebral cortex.

Sign in / Sign up

Export Citation Format

Share Document