Wyniki wyszukiwania - Biblioteka Nauki

1

The objective method of the evaluation of the visual acuity

100%

Hulewicz A.

International Journal of Electronics and Telecommunications

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2019

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tom Vol. 65, No. 1

39--44

EN

The paper presents the use of visual evoked potentials VEP to the objective assessment of visual acuity. Methods of using visual evoked potentials (VEP) rely on the assessment of changes of the electrical action potentials generated within the cortex. To diagnose the degree of weakening eyesight a series of studies on healthy people and visually impaired ones were made. Electrophysiological studies of the eye, using noninvasive VEP examination allow a noninvasive and objective assessment of visual acuity. The use of visual evoked potentials gives the objectivity in assessment of visual acuity what may be very important in ophthalmology. This particularly may concern children examination, people with mental retardation and suspected of simulation.

2

The patch-clamp technique and its application in investigations of the properties of human T lymphocyte potassium channels

88%

Teisseyre A.

Cellular and Molecular Biology Letters

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2001

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tom 06

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nr 1

3

Electrophysiology of GABAergic transmission of single intergeniculate leaflet neurons in rat

75%

Palus K. , Chrobok L. , Lewandowski M. H.

Acta Neurobiologiae Experimentalis

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2015

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tom 75

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nr 1

EN

The intergeniculate leaflet (IGL) of the thalamus constitutes a small but important part of the neural network controlling circadian activity in rodents. It appears that IGL integrates photic cues from retina with non-photic information originating from different nonspecific brain systems. Subsequently, this integrated signal is passed to the master biological clock - the suprachiasmatic nuclei (SCN). The common neurotransmitter of biological clock neural structures, the y-amino-butyric acid (GABA) is expressed in many, if not all, IGL and SCN neurons. Whole-cell patch clamp in vitro electrophysiological experiments were performed in order to evaluate GABA's influence on single IGL neurons in rat. Most neurons were hyperpolarized by GABA application and this effect was caused by activation of GABAa as well as GABAb receptors. The presence of GABAB receptors in rat's IGL has been suggested for the first time.

4

An integrated electromechanical model for the cochlear microphonic

75%

Ayat M. , Teal P. D. , McGuinness M.

Biocybernetics and Biomedical Engineering

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2014

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tom Vol. 34, no. 4

206--219

EN

The cochlear microphonic (CM) is an electrical signal generated inside the cochlea in response to sound. This electrical signal reflects mechanical activity in the cochlea and the excitation processes involved in its generation. However, the difficulty of obtaining this signal and the simplicity of obtaining other signals such as otoacoustic emissions have discouraged the use of the cochlear microphonic as a tool for studying cochlear functions. In this article, a model of the cochlea is presented which integrates both mechanical and electrical aspects, enabling the interaction between them to be investigated. The resulting model is then used to observe the effect of the cochlear amplifier on the CM. The results indicate that while the cochlear amplifier significantly amplifies the basilar membrane displacement, the effect on the CM is less significant. Both of these outcomes are consistent with previous physiological findings. Moreover, the close match between mechanical and electrical predictions of the model and experimental measurements validates the model, and suggests that further investiga- tions using the model into various pathologies and anomalies are warranted.

5

Monitorowanie czynności skurczowej macicy

75%

Radomski D. , Grzanka A. , Graczyk S.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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tom Vol. 49, nr 4

139-141

PL

Monitorowanie aktywności skurczowej macicy jest ważnym klinicznym obszarem zastosowań bioinżynierii medycznej. Przedstawiono metodę analizy bioelektrycznej czynności skurczowej macicy. Bazując na nieliniowym modelu opisującym elektrofizjologię skurczu macicy, przedstawiono wykorzystanie wskaźnika entropii z próby sygnału elektromiograficznego macicy do różnicowania aktywności mechanicznej macicy. Uzyskane wyniki sugerują możliwość zastosowania tego wskaźnika do prognozy ryzyka porodu przedwczesnego.

EN

Monitoring of uterine contractions is one of important clinical application of biomedical engineering. This paper describes the new method of an analysis of bioelectrical activity of an uterus. Basing on a non-linear model describing electrophysiology of a uterine muscle contraction, we used the sample entropy index computed for an electrohysterographical signal to differentiate a state of mechanical uterine activities. The obtained results suggest that this index could be used for assessment of a preterm labor risk.

6

Gravireception and graviresponse in ciliates

75%

Machemer H. , Braucker R.

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1992

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tom 31

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nr 4

7

On the crowd models for the patch-clamp data

75%

Grzywna Z. J. , Siwy Z. , Bashford C. L.

Cellular and Molecular Biology Letters

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1996

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tom 01

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nr 3

EN

Patch clamp data of PETP track-etched membranes have been analysed by the crowd model based on three i.e. regular, exponential and delayed maps of the logistic family. The same data were worked out for all equations, indicating expressive difference between theoretical predictions of the models with constant coefficients and experimental data. The differences disappeared for suitably chosen time dependent coefficients. Some possibilities of relating the functional forms of the logistic coefficients to the "dynamical structure" of a membrane as well as "the memory" of a system have also been discussed.

8

The human frontal eye fields in attention and eye movements

63%

Muggleton N. G.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

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nr 5

9

The effect of alpha-tocopherol in the acute ethanol intake and its withdrawal on penicillin-induced epilepsy

63%

Kozan R. , Ayyildiz M. , Yildirim M. , Agar E.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

|

nr 2

177-188

EN

The present study was designed to investigate the influence of acute ethanol intake and its withdrawal on the anticonvulsant effect of alpha-tocopherol in penicillin-induced epileptiform activity. Ethanol-treated rats received a daily dose of 3 g/kg or 9.0 g/kg of 30% ethanol solution for 3 days. Thirty minutes after penicillin injection (500 units, i.c.), the most effective dose of alpha-tocopherol (500 mg/kg) was administered intramuscularly (i.m.). Acute administration of ethanol, in a dose of 3 g/kg, did not change either frequency or amplitude of penicillin-induced epileptiform activity, while dose of 9 g/kg ethanol significantly decreased the mean frequency of penicillin-induced epileptiform ECoG activity in the ethanol-treated group. Ethanol (9 g/kg) withdrawal also caused an increase in the amplitude of epileptiform ECoG activity in the withdrawal group. The results suggest that acute administration of high dose ethanol (9 g/kg) and alpha-tocopherol have some limited anticonvulsive effects in penicillin-induced epileptiform activity in rats.

10

Biophysical changes induced by cholesterol on phosphatidylcholine artificial biomembranes containing alamethicin oligomers

63%

Cernescu A. , Luchian T.

Open Physics

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2006

|

tom 4

|

nr 2

155-167

EN

Cholesterol is an important constituent of eukaryotic cell membranes, whose interaction with phospholipids leads to a broad range of biological roles, such as: maintenance of proper fluidity, formation of raft domains, reduction of passive permeability of various chemical species through the bilayer (e.g., glucose, glycerol, K+, Na+ and Cl− ions), and increased mechanical strength of the membrane. In this work we studied an interesting paradigm, as to whether cholesterol-containing phosphatidylcholine biomembranes influence the kinetics and transport features of alamethicin oligomers embedded into it. We demonstrate that moderate relative amounts of cholesterol increase the electrical conductance of various sub-conductance states of the alamethicin oligomer, caused probably by a non-monotonic change in the lumped dipole moment of the biomembrane. Our data suggest that biomembrane stiffness caused by cholesterol, visibly modifies the association-dissociation rates of alamethicin oligomerization in the biomembrane. Moreover, increasing concentrations of cholesterol seem to lead to more stable intermediate alamethicin oligomers. We show that in the presence of cholesterol, as the diameter of the alamethicin oligomer increases, so does the time of another monomer to get picked up. These results brings into focus the interesting issue of how oligomerization of proteins affects their interaction affinities for membrane-based lipids.

11

Electrophysiological characterization of synaptic connections of neurons of the thalamic reticular nucleus

63%

Ulrich D.

Acta Neurobiologiae Experimentalis

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2005

|

tom 65

|

nr 5

12

Deep brain recordings

63%

Neagu B. , Chen R.

Biocybernetics and Biomedical Engineering

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2011

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tom Vol. 31, no. 3

19-33

EN

Depth recordings from human subcortical structures have improved our knowledge of human brain circuitries and provided better understanding of the effects and mechanism of action of deep brain stimulation. Two types of signals can be recorded: single unit spikes and local field potentials (LFP). The basal ganglia (BG) are particularly well suited for deep brain recordings and here we review how the oscillatory activities recorded in these structures helped improve our understanding of the sensorimotor brain functions in particular, along with cognitive and emotional-motivational. The oscillations may be classified by frequency into bands at < 8, 8-30 and> 60 Hz. The best characterized band is the 8-30 Hz and existing evidence suggests that it is antikinetic and inversely related to motor processing. On the other hand, accumulating evidence suggests that the > 60 Hz band may be related to normal function.

13

Electrophysiology and pharmacology of the optic input to the rat intergeniculate leaflet in vitro

63%

Blasiak A. , Blasiak T. , Lewandowski M. H.

Journal of Physiology and Pharmacology

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2009

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tom 60

|

nr 1

171-180

EN

The mammalian intergeniculate leaflet (IGL) of the thalamus is a neuronal element of the circadian timing system, which receives direct photic input from the retina. The purpose of this study was to analyze responses of rat IGL neurons in vitro to optic tract stimulation and to identify neurotransmitters released from the terminals of retinal ganglion cells in this structure. Following optic tract stimulation, most of the responding IGL cells were excited and only a minority of them were inhibited. Neurons showing the excitatory response were tested in the presence of AP-5, a selective antagonist of NMDA receptors. In most cases the responses were only partially inhibited by the presence of AP-5. Complete disappearance of excitatory responses was achieved by adding CNQX, an AMPA/kainate receptor-selective antagonist, to the standard incubation fluid. Inhibitory responses were blocked or considerably attenuated in the presence of bicuculline, a GABAA receptor antagonist, in the ACSF. This study demonstrated that glutamate is the main neurotransmitter mediating optic tract input to the IGL, acting mainly via non-NMDA ionotropic receptors. It was also shown that NMDA and GABAA receptors are involved in passing photic input to the IGL, albeit to a much lesser extent.

14

Karaczan amerykański jako model badań wpływu pola elektromagnetycznego na układ nerwowy

63%

Wyszkowska J. , Stankiewicz M. , Krawczyk A. , Zyss T.

Przegląd Elektrotechniczny

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2005

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tom R. 81, nr 12

78-80

PL

Artykuł opisuje badania, mające na celu poddanie organizmu karaczana amerykańskiego (Periplaneta americana) ekspozycji na pole elektromagnetyczne i ocena jego wpływu na funkcjonowanie układu nerwowego z wykorzystaniem technik elektrofizjologicznych. Przedstawiono warunki ekspozycji oraz założenia przyszłych doświadczeń.

EN

This paper describes the investigations of the effects of an influence of electromagnetic field on nerve excitation in cockroach (Periplaneta americana) with the use of electrophysiological techniques. Electromagnetic field exposure as well as the preliminary results have been presented and some concept of future study too.

15

Clinical evaluation and cellular electrophysiology of a recessive CLCN1 patient

63%

Lucchiari S. , Ulzi G. , Magri F. , Bucchia M. , Corbetta F. , Servida M. , Moggio M. , Comi G. P. , Lecchi M.

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nr 5

16

The electrical potential difference through the foot epithelium of the snail Achatina achatina, Lameere during mechanical and chemical stimulation

63%

Tyrakowski T. , Holynska I. , Lampka M. , Kaczorowski P.

Folia Biologica

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2006

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tom 54

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nr 3-4

17

Preparation of neuronal nets for visualization

63%

Katkowska M. J.

Cellular and Molecular Biology Letters

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1996

|

tom 01

|

nr 3

EN

There is a great variety of techniques for complete neurone visualization currently available. Each of them has some advantages and disadvantages. The selection one of them depends upon the requirements of the situation. One of the most useful techniques for observing individual neurones has been the Golgi method with its variations. This method has been extended from the light microscopic to the ultrastructural level. The correlation of neural structure and function was advanced with the technique of intracellular injection of the fluorescent dyes. Investigations of the cross-correlations between morphology, electrophysiology and immunohistochemistry of neurones have significantly advanced current knowledge of the complex organization of at least some parts of the nervous system. Some crucial parameters including the selection of the dyes, the injection technique and tissue processing as well as the appropriate immunohistochemical fluorescent markers are discussed. Cell reconstruction techniques also are mentioned.

18

The responsiveness of the rat intergeniculate leaflet neurons to glutamatergic agonists

63%

Blasiak A. , Pekala D. , Lewandowski M. H.

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tom 58

|

nr 4

EN

The intergeniculate leaflet (IGL) has been shown to be a functional constituent of the circadian timing system. The IGL receives a monosynaptic input from the retina and is known to mediate some of the effects of light on the circadian clock. In the majority of retinal ganglion cells, glutamate functions as an excitatory neurotransmitter. The effect of monosodium glutamate and N-methyl-D-aspartate (NMDA), on the extracellularly recorded discharge activity of IGL neurons was studied in vitro. The application of monosodium glutamate induced either an excitatory, a biphasic or an inhibitory response. Application of NMDA induced an excitatory response in the majority of tested neurons. To determine the role of NMDA receptors in the response to glutamate application, the selective antagonist of NMDA receptors- AP-5, was applied to the incubation medium. The presence of AP-5 reduced the response of the IGL cells to focal application of glutamate and completely blocked their responsiveness to NMDA. To clarify whether GABAergic interneurons are involved in mediation of the inhibitory effects of glutamate, we repeated our experiments in the presence of bicuculline in the incubation medium. Since bicuculline did not influence the observed inhibitory effects, the involvement of GABAA receptors was excluded. The present study provides the first electrophysiological evidence that neurons in the rat IGL, respond to glutamate probably through NMDA receptors. However, our results also suggest that other types of glutamate receptors may play an additional role in mediating the action of this excitatory amino acid on the IGL neurons.

19

Hemispheric asymmetry in event related potentials associated with positive and negative emotions

63%

Sobotka S. , Grabowska A. , Grodzicka J. , Wasilewski R. , Budohoska W.

Acta Neurobiologiae Experimentalis

|

1992

|

tom 52

|

nr 4

20

Asymmetry in visual evoked potentials to gratings registered in the two hemispheres of the human brain

63%

Grabowska A. , Nowicka A. , Szatkowska I.

Acta Neurobiologiae Experimentalis

|

1992

|

tom 52

|

nr 4