scholarly journals Quantification of cortical neurons: a neuroanatomical myth in neuroscience

2017 ◽  
Vol 34 (01) ◽  
pp. 031-035
Author(s):  
J. Parra ◽  
J. Aguirre ◽  
F. Mejía
Keyword(s):  
Cerebral Cortex ◽  
Life Cycle ◽  
Cortical Neurons ◽  
Human Cerebral Cortex ◽  
Human Cortex ◽  
Factors Influencing ◽  
Pathological Conditions ◽  
Cerebral Cortical Neurons ◽  
Main Factors ◽  
Value Changes

AbstractThe objective was to analyze whether there was a definite number of cerebral cortical neurons for humans. Methodology: data was examined for the total number of brain neurons in the literature related to the field of neuroscience. This suggested that the human cerebral cortex has a large number of neurons whose value changes with the life cycle due to several factors that lead to have an indefinite number. Discussion: an analysis based on the literature showed the main factors influencing the total number of cortical neurons such as neurogenesis, apoptosis during life cycle, gender and pathological conditions. The inconsistent assessment of the number of neurons in the human cortex has been discussed by several authors, emphasizing that the values that have been displayed in the literature are presumably uncertain and are based on the views of some authors or the conceptions of others without carrying out replicable scientific studies. The above described has exhibited variable and inconsistent values in different texts about this issue. It has been concluded that the total number of cortical neurons varies due to diverse factors that play a role in determining the number of neurons in the human cerebral cortex.

scholarly journals VII. The exact histological localisation of the visual area of the human cerebral cortex

1900 ◽  
Vol 193 (185-193) ◽  
pp. 165-222 ◽  
Keyword(s):  
Cerebral Cortex ◽  
County Council ◽  
Visual Area ◽  
Human Cerebral Cortex ◽  
Human Cortex ◽  
Physiological Laboratory ◽  
Sensory Area ◽  
University College ◽  
Cortex Cerebri

The object of the present paper is to define by histological methods the exact limitations of the visuo-sensory area of the human cortex cerebri. The investigation to be described has occupied upwards of three years. It was commenced during the summer of 1896 in the pathological laboratory of the County Asylum, Rainhill, Lancashire; it was continued during the next three years in the physiological laboratory of Mason University College, Birmingham; and it has been completed in the pathological laboratory of the London County Council at Claybury. Owing to the remarkable facilities for research granted to workers in the last-named laboratory, it has been possible to bring this investigation to a much more rapid conclusion than would otherwise have been possible. A general summary of the paper follows this introduction, and it is succeeded for convenience of reference by a list of the sections into which the paper is divided.

GABA as an inhibitory neurotransmitter in human cerebral cortex

1989 ◽  
Vol 62 (5) ◽  
pp. 1018-1027 ◽  
Author(s):  
D. A. McCormick
Keyword(s):  
Cerebral Cortex ◽  
Cortical Neurons ◽  
Epileptiform Activity ◽  
Reversal Potential ◽  
Membrane Conductance ◽  
Pyramidal Cells ◽  
Excitatory Postsynaptic Potential ◽  
Gamma Aminobutyric Acid ◽  
Human Cerebral Cortex ◽  
Inhibitory Neurotransmitter

1. The possible role of gamma-aminobutyric acid (GABA) as an inhibitory neurotransmitter in the human cerebral cortex was investigated with the use of intracellular recordings from neocortical slices maintained in vitro. 2. Electrical stimulation of afferents to presumed pyramidal cells resulted in an initial excitatory postsynaptic potential (EPSP) followed by fast and slow inhibitory postsynaptic potentials (IPSPs). The early IPSP had an average reversal potential of -68 mV, was associated with a mean 67-nS increase in membrane conductance, was reduced by the GABAA antagonist bicuculline, was sensitive to the intracellular injection of Cl-, and was mimicked by the GABAA agonist muscimol. 3. The late IPSP, in contrast, had an average reversal potential of -95 mV, was associated with a mean 12-nS increase in membrane conductance, was reduced by the GABAB antagonist phaclofen, and was mimicked by the GABAB agonist baclofen. 4. Block of the early IPSP by bicuculline or picrotoxin led to the generation of paroxysmal epileptiform activity, which could be further enhanced by reduction of the late IPSP. 5. These data strongly support the hypothesis that GABA is a major inhibitory neurotransmitter in the human cerebral cortex and that GABAergic IPSPs play an important role in controlling the excitability and responsiveness of cortical neurons.

The actions of motilin, luteinizing hormone releasing hormone, cholecystokinin, somatostatin, vasoactive intestinal peptide, and other peptides on rat cerebral cortical neurons

1980 ◽  
Vol 58 (6) ◽  
pp. 612-623 ◽  
Author(s):  
J. W. Phillis ◽  
J. R. Kirkpatrick
Keyword(s):  
Cerebral Cortex ◽  
Luteinizing Hormone ◽  
Vasoactive Intestinal Peptide ◽  
Cortical Neurons ◽  
Spontaneous Firing ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Depressant Action ◽  
Cerebral Cortical Neurons ◽  
Excitatory Action

The effects of a number of neuronally localized peptides have been ascertained on corticospinal and other unidentified neurons in the rat cerebral cortex. Motilin, somatostatin, and luteinizing hormone releasing hormone excited most of the corticospinal neurons on which they were tested. Cholecystokinin, Met-enkephalin, vasoactive intestinal peptide, and neurotensin also excited some corticospinal neurons. Many nonidentified neurons were excited by all of these peptides. Met-enkephalin had a depressant action on some (14%) corticospinal neurons. Leu-enkephalin depressed many identified and nonidentified neurons and had an excitatory action on a few neurons. Both excitatory and inhibitory actions of the enkephalins were antagonized by naloxone. Thyrotropin-releasing hormone had predominantly depressant actions on the spontaneous firing of corticospinal and nonidentified neurons but did excite some unidentified cortical neurons. Secretin had no effect on the firing of most of the neurons tested.

scholarly journals Cellular Scaling Rules for the Brains of Marsupials: Not as “Primitive” as Expected

2017 ◽  
Vol 89 (1) ◽  
pp. 48-63 ◽  
Author(s):  
Sandra E. Dos Santos ◽  
Jairo Porfirio ◽  
Felipe B. da Cunha ◽  
Paul R. Manger ◽  
William Tavares ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Brain Structure ◽  
Cortical Neurons ◽  
Neuronal Cell ◽  
Sister Group ◽  
Mammalian Evolution ◽  
Cerebellar Neurons ◽  
Scaling Relationships ◽  
Cerebral Cortical Neurons ◽  
The Brain

In the effort to understand the evolution of mammalian brains, we have found that common relationships between brain structure mass and numbers of nonneuronal (glial and vascular) cells apply across eutherian mammals, but brain structure mass scales differently with numbers of neurons across structures and across primate and nonprimate clades. This suggests that the ancestral scaling rules for mammalian brains are those shared by extant nonprimate eutherians - but do these scaling relationships apply to marsupials, a sister group to eutherians that diverged early in mammalian evolution? Here we examine the cellular composition of the brains of 10 species of marsupials. We show that brain structure mass scales with numbers of nonneuronal cells, and numbers of cerebellar neurons scale with numbers of cerebral cortical neurons, comparable to what we have found in eutherians. These shared scaling relationships are therefore indicative of mechanisms that have been conserved since the first therians. In contrast, while marsupials share with nonprimate eutherians the scaling of cerebral cortex mass with number of neurons, their cerebella have more neurons than nonprimate eutherian cerebella of a similar mass, and their rest of brain has fewer neurons than eutherian structures of a similar mass. Moreover, Australasian marsupials exhibit ratios of neurons in the cerebral cortex and cerebellum over the rest of the brain, comparable to artiodactyls and primates. Our results suggest that Australasian marsupials have diverged from the ancestral Theria neuronal scaling rules, and support the suggestion that the scaling of average neuronal cell size with increasing numbers of neurons varies in evolution independently of the allocation of neurons across structures.

On the Specificity of Histamine H2-Receptor Antagonists in the Rat Cerebral Cortex

1975 ◽  
Vol 53 (6) ◽  
pp. 1205-1209 ◽  
Author(s):  
J. W. Phillis ◽  
G. K. Kostopoulos ◽  
A. Odutola
Keyword(s):  
Cerebral Cortex ◽  
Cortical Neurons ◽  
Rat Cerebral Cortex ◽  
Receptor Antagonists ◽  
H2 Receptor Antagonists ◽  
Histamine H2 Receptor ◽  
H2 Receptor ◽  
Cerebral Cortical Neurons

The effects of iontophoretically applied histamine H2-receptor antagonists and their antagonism of various amines, acetylcholine (ACh), and adenosine 5′-monophosphate (5′-AMP) were studied on spontaneously active rat cerebral cortical neurons. Metiamide selectively blocked the depressant actions of histamine. Burimamide, in amounts necessary for histamine antagonism, also antagonized the depressant effects of noradrenaline, dopamine, and 5-hydroxytryptamine. Neither antagonist affected 5′-AMP-induced depressions, but both reduced or blocked the excitatory actions of ACh. It is concluded that metiamide may be useful as a reliable antagonist of H2 receptors on cerebral cortical neurons.

The Postnatal Development of the Human Cerebral Cortex. Volume III; The Cortex of the Three-Month Infant

PEDIATRICS ◽  
1948 ◽  
Vol 2 (4) ◽  
pp. 506-506
Author(s):  
ALLAN M. BUTLER
Keyword(s):  
Cerebral Cortex ◽  
Growth And Development ◽  
Horizontal Layer ◽  
Nerve Cells ◽  
Human Cerebral Cortex ◽  
Voluntary Activity ◽  
Human Cortex ◽  
The Third ◽  
Layer 2 ◽  
Number Of Cells

This is the third volume of Dr. Conel's unique monographic series which extends his meticulous microscopic study of the development of the human cortex to three months of age. It presents in detail the histologic criteria of development by which comparison may be made of brains of the same or different ages or of various areas within the cortex of one brain. The criteria are: 1. width of entire cortex and of each horizontal layer; 2. number of cells; 3. size of nerve cells; 4. condition of the chromophil substance ; 5. neurofibrils ; 6. size, compactness of structure (including varicosities), and length of processes of nerve cells; 7. pedunculated bulbs; 8. size and quantiy of exogenous fibers; and 9, state of myelination. The manifestations of growth and development of the cerebral cortex by these criteria correlate with observations on the progression of voluntary activity in infants.

Brain benzodiazepine levels following intravenous administration of [3H]diazepam: Relationship to the potentiation of purinergic depression of central nervous system neurons

1979 ◽  
Vol 57 (9) ◽  
pp. 1040-1042 ◽  
Author(s):  
Phil Skolnick ◽  
Steven M. Paul ◽  
Paul J. Marangos
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Intravenous Injection ◽  
Cortical Neurons ◽  
Benzodiazepine Receptors ◽  
Time Schedule ◽  
Adenosine Uptake ◽  
Cerebral Cortical Neurons

Levels of [3H] benzodiazepine were measured in rat cerebral cortex following intravenous injection of [3H]diazepam using a dose and time schedule reported to elicit a marked potentiation of the depressant effects of iontophoretically applied 5′-AMP to rat cerebral cortical neurons. The levels of [3H]benzodiazepine obtained strongly suggest (i) that blockade of adenosine uptake as a mechanism for this potentiation is not consistent with the potency of diazepam as an inhibitor of adenosine uptake in vitro, and (ii) that a potentiative interaction of adenosine and diazepam may reflect the binding of these compounds to benzodiazepine receptors.

C-fos, ERK1/2, MAP2, NOTCH1 Proteins Expression Patterns in Human Cerebral Cortex Neurons after Ischemic Stroke

2020 ◽  
Vol 75 (3) ◽  
pp. 226-233
Author(s):  
Svetlana P. Sergeeva ◽  
Aleksey V. Lyundup ◽  
Valery V. Beregovykh ◽  
Petr F. Litvitskiy ◽  
Aleksey A. Savin ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Ischemic Stroke ◽  
Expression Patterns ◽  
Immunohistochemical Method ◽  
Left Middle Cerebral Artery ◽  
Contralateral Hemisphere ◽  
Human Cerebral Cortex ◽  
Fos Protein ◽  
Urgent Task ◽  
Indirect Immunoperoxidase

Background. The search for protein (these include c-fos, ERK1/2, MAP2, NOTCH1) expression that provide neuroplasticity mechanisms of the cerebral cortex after ischemic stroke (IS) patterns is an urgent task. Aims to reveal c-fos, ERK1/2, MAP2, NOTCH1 proteins expression patterns in human cerebral cortex neurons after IS. Materials and methods. We studied 9 left middle cerebral artery (LMCA) IS patients cerebral cortex samples from 3 zones: 1 the zone adjacent to the necrotic tissue focus; 2 zone remote from the previous one by 47 cm; 3 zone of the contralateral hemisphere, symmetric to the IS focus. Control samples were obtained from 3 accident died people. Identification of targeted proteins NSE, c-fos, ERK1/2, MAP2, NOTCH1 was performed by indirect immunoperoxidase immunohistochemical method. Results. Moving away from the ischemic focus, there is an increase in the density of neurons and a decrease in the damaged neurons proportion, the largest share of c-fos protein positive neurons in zone 2, NOTCH1 positive neurons in zone 1, smaller fractions of ERK1/2 and MAP2 positive neurons compared to the control only in samples of zone 1. Conclusions. With the IS development, the contralateral hemisphere is intact tissue increased activation zone, while the zones 1 and 2 have pathological activation signs. In zone 1 of the range, the adaptive response of the tissue decreases, and in zone 2 it expands. Therefore, a key target for therapeutic intervention is zone 2.

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