scholarly journals A METHOD OF COUNTING THE ACTUAL NUMBER OF PURKINJE CELLS PRESENT IN A GIVEN AREA OF CEREBELLUM, AND ITS APPLICATION IN TEN CLINICAL CASES

1914 ◽  
Vol 20 (6) ◽  
pp. 595-598
Author(s):  
Frederic Wade Hitchings
Keyword(s):  
Nerve Cell ◽  
Purkinje Cells ◽  
Cell Activity ◽  
Nerve Cells ◽  
Actual Number ◽  
Cell Exhaustion ◽  
Normal Man ◽  
Maximum Cell ◽  
The Individual ◽  
Clinical Cases

1. This method of determining the actual number of Purkinje cells present in a given area of cerebellum is practicable and of sufficient accuracy to make it another useful means of studying nerve cell activity. 2. In its application to clinical cases it is found that increasing nerve cell exhaustion is accompanied by increasing nerve cell disappearance, although it is recognized that theoretically complete nerve cell exhaustion could be present without nerve cell disappearance on account of the individual dying before phagocytic action could take place. 3. This disappearance of nerve cells corroborates the theories and observations made on phagocytosis of nerve cells, inasmuch as it shows that nerve cells disappear from the brain. 4. While there are too few cases to establish a normal actual Purkinje cell count, it is of interest to note that there were 16.6 per cent. fewer cells in the case with the maximum cell exhaustion (57 per cent.) than in the case of the normal man (2 per cent.).

Calcium Signals in Nerve Cells

Physiology ◽  
1991 ◽  
Vol 6 (1) ◽  
pp. 6-10 ◽  
Author(s):  
PG Kostyuk ◽  
AV Tepikin
Keyword(s):  
Endoplasmic Reticulum ◽  
Ion Channels ◽  
Nerve Cell ◽  
Second Messengers ◽  
Cell Activity ◽  
Nerve Cells ◽  
Calcium Signals ◽  
Intracellular Ca ◽  
Ca Ions

Increases in intracellular Ca ions follow each cycle of nerve cell activity. Sources of Ca are voltage- and receptor-operated membrane ion channels and endoplasmic reticulum (ER). Ca release from ER can be triggered by different second messengers, and uptake into the ER can terminate the Ca signal.

On the Excitation Processes of the Conscious and Subconscious Mind

1929 ◽  
Vol 75 (310) ◽  
pp. 371-394 ◽  
Author(s):  
W. Burridge
Keyword(s):  
Nerve Cell ◽  
Cell Activity ◽  
Nerve Cells ◽  
Mental Activity ◽  
Excitable Tissue ◽  
Excitation Processes ◽  
The Mind ◽  
The Brain

Studies of the mind of man and of the heart of the frog, though normally deeply divided, can be bridged when two postulates are granted. The first postulate is that the quality of excitability, on which nerve-cell activity is based, can be studied in any other excitable tissue; the second is that mental activity, as we know it, depends on the presence of excitable nerve-cells in the brain. The postulates being granted, it becomes legitimate to apply the results of experiments on excitability performed with the frog's heart in explanation of the mode of working of the brain and mind.

A.F. De Mezer Posthumous changes in nerve cells, detected by staining according to Nissl. —University Izvestiya. 1900, August, No.8

1901 ◽  
Vol IX (1) ◽  
pp. 208-209
Author(s):  
B. Vorotynsky
Keyword(s):  
Nerve Cell ◽  
Nerve Cells ◽  
The University

The work was carried out in the laboratory of the pathological anatomical institute of the University of St. Vladimira. First, the author describes the structure of the nerve cell, which is detected by staining by the Nissl method, and he separately stops at describing the structure of the processes, nucleus and nucleolus.

scholarly journals Efficient generation of reciprocal signals by inhibition

2012 ◽  
Vol 107 (9) ◽  
pp. 2453-2462 ◽  
Author(s):  
Sung-min Park ◽  
Esra Tara ◽  
Kamran Khodakhah
Keyword(s):  
Purkinje Cells ◽  
Granule Cell ◽  
Granule Cells ◽  
Mossy Fiber ◽  
Cell Activity ◽  
Common Mechanism ◽  
Input Output ◽  
Firing Rates ◽  
Neuronal Computation ◽  
The Brain

Reciprocal activity between populations of neurons has been widely observed in the brain and is essential for neuronal computation. The different mechanisms by which reciprocal neuronal activity is generated remain to be established. A common motif in neuronal circuits is the presence of afferents that provide excitation to one set of principal neurons and, via interneurons, inhibition to a second set of principal neurons. This circuitry can be the substrate for generation of reciprocal signals. Here we demonstrate that this equivalent circuit in the cerebellar cortex enables the reciprocal firing rates of Purkinje cells to be efficiently generated from a common set of mossy fiber inputs. The activity of a mossy fiber is relayed to Purkinje cells positioned immediately above it by excitatory granule cells. The firing rates of these Purkinje cells increase as a linear function of mossy fiber, and thus granule cell, activity. In addition to exciting Purkinje cells positioned immediately above it, the activity of a mossy fiber is relayed to laterally positioned Purkinje cells by a disynaptic granule cell → molecular layer interneuron pathway. Here we show in acutely prepared cerebellar slices that the input-output relationship of these laterally positioned Purkinje cells is linear and reciprocal to the first set. A similar linear input-output relationship between decreases in Purkinje cell firing and strength of stimulation of laterally positioned granule cells was also observed in vivo. Use of interneurons to generate reciprocal firing rates may be a common mechanism by which the brain generates reciprocal signals.

The unification of neural activity

1968 ◽  
Vol 171 (1024) ◽  
pp. 353-359 ◽  
Keyword(s):  
Nervous System ◽  
Neural Activity ◽  
Nerve Cells ◽  
General Nature ◽  
Central Importance ◽  
Stimulus Response ◽  
Simple Hypothesis ◽  
Neural Organization ◽  
The Individual ◽  
The Brain

In studying the brain, two levels of investigation emerge naturally. One of these concerns itself with properties of nerve cells, their numbers, patterns of firing, interconnexions, and so forth. The other considers the whole nervous system in what one may call ‘macroscopic’ terms. Thus it discusses ‘stimulus’, ‘response’, ‘decision’, etc. At this latter level, the nervous system operates with considerable unity. The individual nerve cells must therefore be linked in a well-integrated manner and the general nature of this integration has been recognized, especially by neurophysiologists such as Sherrington, to present a problem of central importance for our understanding of the brain. In previously published work, I have put forward a theory of how this unification of neural activity might be achieved and of a possible molecular biological basis of the necessary neural organization. In this talk I restrict myself to the first of these and thus give an account of what might be called the basic logic of the unification. I also indicate briefly how a simple hypothesis about the basis of memory would fit into such a theory.

Modeling the spatiotemporal intracellular calcium dynamics in nerve cell with strong memory effects

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hardik Joshi ◽  
Brajesh Kumar Jha
Keyword(s):  
Intracellular Calcium ◽  
Nerve Cell ◽  
Time Derivative ◽  
Classical Case ◽  
Nerve Cells ◽  
Calcium Dynamics ◽  
Intracellular Calcium Level ◽  
Calbindin D ◽  
The Impact ◽  
Fractional Parameter

Abstract Calcium signaling in nerve cells is a crucial activity for the human brain to execute a diversity of its functions. An alteration in the signaling process leads to cell death. To date, several attempts registered to study the calcium distribution in nerve cells like neurons, astrocytes, etc. in the form of the integer-order model. In this paper, a fractional-order mathematical model to study the spatiotemporal profile of calcium in nerve cells is assembled and analyzed. The proposed model is solved by the finite element method for space derivative and finite difference method for time derivative. The classical case of the calcium dynamics model is recovered by setting the fractional parameter and that validates the model for classical sense. The numerical computations have systematically presented the impact of a fractional parameter on nerve cells. It is observed that calbindin-D28k provides a significant effect on the spatiotemporal variation of calcium profile due to the amalgamation of the memory of nerve cells. The presence of excess amounts of calbindin-D28k controls the intracellular calcium level and prevents the nerve cell from toxicity.

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