The relationship between the background impulse activity of cortical neurons and the electrocorticogram phases

1965 ◽  
Vol 59 (6) ◽  
pp. 597-600
Author(s):  
N. N. Vasilevskii
Keyword(s):  
Cortical Neurons ◽  
Impulse Activity ◽  
Background Impulse Activity ◽  
The Relationship

Possible Effects of Depolarizing GABAA Conductance on the Neuronal Input–Output Relationship: A Modeling Study

2005 ◽  
Vol 93 (6) ◽  
pp. 3504-3523 ◽  
Author(s):  
Kenji Morita ◽  
Kunichika Tsumoto ◽  
Kazuyuki Aihara
Keyword(s):  
Firing Rate ◽  
Cortical Neurons ◽  
Reversal Potential ◽  
Pyramidal Cells ◽  
Resting Potential ◽  
Input Output ◽  
Wide Range ◽  
The Relationship

Recent in vitro experiments revealed that the GABAA reversal potential is about 10 mV higher than the resting potential in mature mammalian neocortical pyramidal cells; thus GABAergic inputs could have facilitatory, rather than inhibitory, effects on action potential generation under certain conditions. However, how the relationship between excitatory input conductances and the output firing rate is modulated by such depolarizing GABAergic inputs under in vivo circumstances has not yet been understood. We examine herewith the input–output relationship in a simple conductance-based model of cortical neurons with the depolarized GABAA reversal potential, and show that a tonic depolarizing GABAergic conductance up to a certain amount does not change the relationship between a tonic glutamatergic driving conductance and the output firing rate, whereas a higher GABAergic conductance prevents spike generation. When the tonic glutamatergic and GABAergic conductances are replaced by in vivo–like highly fluctuating inputs, on the other hand, the effect of depolarizing GABAergic inputs on the input–output relationship critically depends on the degree of coincidence between glutamatergic input events and GABAergic ones. Although a wide range of depolarizing GABAergic inputs hardly changes the firing rate of a neuron driven by noncoincident glutamatergic inputs, a certain range of these inputs considerably decreases the firing rate if a large number of driving glutamatergic inputs are coincident with them. These results raise the possibility that the depolarized GABAA reversal potential is not a paradoxical mystery, but is instead a sophisticated device for discriminative firing rate modulation.

The relationship between callosal axons and cortical neurons in the planum temporale: Alterations in schizophrenia

2011 ◽  
Vol 71 (4) ◽  
pp. 405-410 ◽  
Author(s):  
R. Simper ◽  
M.A. Walker ◽  
G. Black ◽  
E. Di Rosa ◽  
T.J. Crow ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Planum Temporale ◽  
The Relationship

The effect of behavioural arousal on the activity of hypothalamic neurons in unanaesthetized, freely moving rats and rabbits

1982 ◽  
Vol 214 (1195) ◽  
pp. 263-272 ◽  
Keyword(s):  
Neuronal Activity ◽  
Cortical Neurons ◽  
Hypothalamic Neurons ◽  
Extracellular Recordings ◽  
Modal Interval ◽  
Individual Mode ◽  
Consistent Manner ◽  
Freely Moving ◽  
The Relationship ◽  
The Continuum

Experiments were carried out to investigate the relationship between levels of arousal and the temporal discharge pattern of hypothalamic neurons in unanaesthetized, unrestrained rats and rabbits. Extracellular recordings were taken from 22 hypothalamic neurons in animals that had been implanted previously with platinum microwire electrodes. Separate records of neuronal activity were taken from each neuron when the animal was at two extremes of arousal, sleep and alarm, and compared with an intermediate state of arousal, awake and relaxed. The extremes of arousal were defined by simple behavioural criteria, shown to coincide with specific patterns of electrocorticographic activity. Interval distributions were constructed from these records of neuronal activity. The modal interval, but not the frequency of discharge of these neurons, changed in a consistent manner with the level of arousal for all the neurons recorded. The modal interval was always short (9.59 ±1.2 ms (mean ± s.e.), n = 17) during sleep and longer when the animal was alarmed (57.15 ± 7.59 ms, n = 13). When the animals were awake and relaxed the modal interval was between those of sleep and alarm (27.5 ± 2.79 ms, n = 19). Scatter about an individual mode was greater in sleep than during alarm. It is suggested that the continuum of arousal from sleep to alarm is reflected by a continuously shifting modal interval for each hypothalamic neuron. This is essentially similar to reports on the effect of arousal on cortical neurons.

scholarly journals Maladaptive neuropathological syndrome of blood vessel aging

2019 ◽  
pp. 33-40
Author(s):  
A. A. Artemenkov
Keyword(s):  
Cerebral Cortex ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Cortical Neurons ◽  
Circulatory System ◽  
Vascular Wall ◽  
Modern Human ◽  
Wall Thickening ◽  
Additional Risk Factor ◽  
The Relationship

This article discusses the relationship between maladaptation and blood vessel aging. The work shows that upright posture created an additional load on the circulatory system, and the lifestyle of a modern human is an additional risk factor of cardiovascular diseases. It has been suggested that a disorder of the nervous regulation of vascular tone is the main etiopathogenetic mechanism of morphofunctional changes in blood vessels and their aging. We discussed the statute that vascular reactions in humans is based on the formation of a maladaptive circuit in the cerebral cortex, consisting of a matrix of motor, sensory and associative cortical neurons involved in the maladaptive process. This hypothesis is based on the fact that any irritations entering the cerebral cortex from the periphery (thermal, pain, and others) cause cortical-vascular reflex reactions that change their tonic activity. Based on this principle, a model of vascular aging is further constructed, which is based on the maladaptive damage to all layers of the vascular wall (intima, media and adventitia). The opinion is expressed about the need for early diagnosis and prevention of vascular disorders to maintain human health. In conclusion, it is concluded that if the age of a person is really determined by the age of his blood vessels, then in order to achieve active longevity it is necessary to normalize the relationship in the adaptation-maladaptation-environment. Detailed study of hypertrophy and calcification of blood vessels is needed, since aging always reveals vascular wall thickening and stiffness increase.

scholarly journals Length of the Neurogenic Period—A Key Determinant for the Generation of Upper-Layer Neurons During Neocortex Development and Evolution

2021 ◽  
Vol 9 ◽  
Author(s):  
Barbara K. Stepien ◽  
Samir Vaid ◽  
Wieland B. Huttner
Keyword(s):  
Cognitive Abilities ◽  
Cortical Neurons ◽  
Mammalian Species ◽  
Critical Role ◽  
Exact Nature ◽  
Cortical Neurogenesis ◽  
Brain Functions ◽  
The Relationship ◽  
Development And Evolution

The neocortex, a six-layer neuronal brain structure that arose during the evolution of, and is unique to, mammals, is the seat of higher order brain functions responsible for human cognitive abilities. Despite its recent evolutionary origin, it shows a striking variability in size and folding complexity even among closely related mammalian species. In most mammals, cortical neurogenesis occurs prenatally, and its length correlates with the length of gestation. The evolutionary expansion of the neocortex, notably in human, is associated with an increase in the number of neurons, particularly within its upper layers. Various mechanisms have been proposed and investigated to explain the evolutionary enlargement of the human neocortex, focussing in particular on changes pertaining to neural progenitor types and their division modes, driven in part by the emergence of human-specific genes with novel functions. These led to an amplification of the progenitor pool size, which affects the rate and timing of neuron production. In addition, in early theoretical studies, another mechanism of neocortex expansion was proposed—the lengthening of the neurogenic period. A critical role of neurogenic period length in determining neocortical neuron number was subsequently supported by mathematical modeling studies. Recently, we have provided experimental evidence in rodents directly supporting the mechanism of extending neurogenesis to specifically increase the number of upper-layer cortical neurons. Moreover, our study examined the relationship between cortical neurogenesis and gestation, linking the extension of the neurogenic period to the maternal environment. As the exact nature of factors promoting neurogenic period prolongation, as well as the generalization of this mechanism for evolutionary distinct lineages, remain elusive, the directions for future studies are outlined and discussed.

Dynamic Spatiotemporal Synaptic Integration in Cortical Neurons: Neuronal Gain, Revisited

2005 ◽  
Vol 94 (4) ◽  
pp. 2785-2796 ◽  
Author(s):  
Rony Azouz
Keyword(s):  
Firing Rate ◽  
Cortical Neurons ◽  
Temporal Integration ◽  
Synaptic Integration ◽  
Neuronal Membrane ◽  
Network Dynamic ◽  
Alternative Mechanism ◽  
Gain Modulation ◽  
Voltage Gated ◽  
The Relationship

Gain modulation is a ubiquitous phenomenon in cortical neurons, providing flexibility to operate under changing conditions. The prevailing view is that this modulation reflects a change in the relationship between mean input and output firing rate brought about by variation in neuronal membrane characteristics. An alternative mechanism is proposed for neuronal gain modulation that takes into account the capability of cortical neurons to process spatiotemporal synaptic correlations. Through the use of numerical simulations, it is shown that voltage-gated and leak conductances, membrane potential, noise, and input firing rate modify the sensitivity of cortical neurons to the degree of temporal correlation between their synaptic inputs. These changes are expressed in a change of the temporal window for synaptic integration and the range of input correlation over which response probability is graded. The study also demonstrates that temporal integration depends on the distance between the inputs and that this interplay of space and time is modulated by voltage-gated and leak conductances. Thus, gain modulation may reflect a change in the relationship between spatiotemporal synaptic correlations and output firing probability. It is further proposed that by acting synergistically with the network, dynamic spatiotemporal synaptic integration in cortical neurons may serve a functional role in the formation of dynamic cell assemblies.

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