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1.
Brain Sci ; 13(6)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37371425

RESUMO

The accurate detection of emotions has significant implications in healthcare, psychology, and human-computer interaction. Integrating personality information into emotion recognition can enhance its utility in various applications. The present study introduces a novel deep learning approach to emotion recognition, which utilizes electroencephalography (EEG) signals and the Big Five personality traits. The study recruited 60 participants and recorded their EEG data while they viewed unique sequence stimuli designed to effectively capture the dynamic nature of human emotions and personality traits. A pre-trained convolutional neural network (CNN) was used to extract emotion-related features from the raw EEG data. Additionally, a long short-term memory (LSTM) network was used to extract features related to the Big Five personality traits. The network was able to accurately predict personality traits from EEG data. The extracted features were subsequently used in a novel network to predict emotional states within the arousal and valence dimensions. The experimental results showed that the proposed classifier outperformed common classifiers, with a high accuracy of 93.97%. The findings suggest that incorporating personality traits as features in the designed network, for emotion recognition, leads to higher accuracy, highlighting the significance of examining these traits in the analysis of emotions.

2.
Electromagn Biol Med ; 41(3): 335-342, 2022 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35791924

RESUMO

The present study aimed to assess the effect of the rTMS (repetitive Transcranial Magnetic Stimulation) intensity on the permeability of the BBB for brain-targeted drug delivery. For this purpose, different rTMS intensities including 70%, 100%, and 130% of Resting Motor Threshold (RMT) assessed in three groups of rats (three groups of 5 rats). Stimulation applied over the right hemisphere of the animals. The first phase of the study was composed of intravenous administration of Evans Blue Dye (EBD), rTMS stimulation and EBD uptake measurement in both brain hemispheres. The second examination was included rTMS stimulation, injection of the MRI Contrast Agent (CA), and signal intensity measurement in post-contrast images. Each exam also included five rats in a sham group. Thus, the total of 40 male Wistar rats enrolled in this study. There was no significant difference in the amount of EBD accumulated between the right hemisphere of the brain in the sham group and the group with 70% RMT magnetic stimulation, while this figure was significantly higher than the sham group for both 100 and 130% RMT groups. There was also a significant difference in this index between 100 and 130% groups. All of the results from the first phase of the study were consistent with the second assessment representing an upward trend of induced permeability by rising rTMS intensity. The results of this study imply that to cause an effective temporary disruption in the BBB the intensity of 100% RMT or above should be used for stimulation.


Assuntos
Barreira Hematoencefálica , Estimulação Magnética Transcraniana , Animais , Encéfalo/fisiologia , Masculino , Ratos , Ratos Wistar , Estimulação Magnética Transcraniana/métodos
3.
J Biomed Phys Eng ; 12(2): 205-210, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35433520

RESUMO

Background: In the present study, we investigated the application of pulsed magnetic field (MF) (3.5 T, 1 Hz, 8 square-wave/160 µs) permeabilization on murine breast adenocarcinoma cells when administering bleomycin (BLM) in vivo. Objective: This cross-over study aims to find a noninvasive method to facilitate penetration of hydrophilic anti-cancer drugs through the cancerous cells membrane into the cytosoll in order to minimize the side effects of the chemotherapy treatments of tumors. Material and Methods: In this cross-over study, a total of 50 female Balb/c mice were tumorized via homograft. After about 2 weeks, magnetic pulses (3.5 T, 1 Hz, 8 square-wave/160 µs) were applied to tumor-bearing mice 3 min after intratumoral BLM solution injection. Tumor volume was measured every 48 h during 22 days. Results: The results showed that the difference between the BLM plus 3.5 T MF group versus the sham control or sham MF groups was significant. Uptake of BLM molecules by tumoral cells in the BLM plus 3.5 T MF group versus the BLM control group was 7- folds higher that this result was statistically insignificant (P<0.05, SEM=266.8676, analysis of variance). Conclusion: Significant cell permeabilization to BLM requires greater MF strength or exposure time. Further investigation is necessary.

4.
Cell J ; 23(4): 445-450, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34455720

RESUMO

OBJECTIVE: The cell membrane is a major barrier for delivery of hydrophilic drugs and molecules into the cells. Although low voltage and high frequency electric fields (LVHF) are proposed to overcome the cell membrane barrier, the mechanism of membrane permeabilization is unclear. The aim of study is to investigate endocytosis pathways as a possible mechanism for enhancing uptake of bleomycin by LVHF. MATERIALS AND METHODS: In this experimental study, MCF-7 cells were exposed to bleomycin or to electric fields with various strengths (10-80 V/cm), frequency of 5 kHz, 4000 electric pulse and 100 µs duration in the presence and absence of three endocytosis inhibitors-chlorpromazine (Cpz), amiloride (Amilo) and genistein (Geni). We determined the efficiency of these chemotherapeutic agents in each group. RESULTS: LVHF, depending on the intensity, induced different endocytosis pathways. Electric field strengths of 10 and 20 V/cm stimulated the macropinocytosis route. Clathrin-mediated endocytosis was observed at electric field intensities of 10, 30, 60 and 70 V/cm, whereas induction of caveolae-mediated endocytosis was observed only at the lowest electric field intensity (10 V/cm). CONCLUSION: The results of this study imply that LVHF can induce different endocytosis pathways in MCF-7 cells, which leads to an increase in bleomycin uptake.

5.
Med Hypotheses ; 153: 110615, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34214759

RESUMO

Transcranial Direct Current Stimulation (tDCS) is a non-invasive and sub-threshold method for altering the excitability of neurons to achieve target conditions. Many clinical applications of tDCS are in progress including treatment of neurological disease. Despite the therapeutic and practical potentials of tDCS, the precise mechanism of its impact is still unclear to a large extent. The initial perspective about the effect of tDCS on synaptic plasticity was that electric stimulation of the brain degrades the threshold of neural firing, thus facilitating electrical transmission and improving conductivity between neurons and ultimately leading to changes in the processing of information. However, new results of some experimental studies have changed the initial perspective. Recently, calcium imaging has shown sudden calcium fluctuations, followed by a change in cortical metaplasticity under tDCS. These pieces of evidence pinpoint the important role of astrocytes in describing the effect of tDCS. Astrocytes are glial cells that are traditionally viewed with only a supportive and nutritional role, but recent research expresses that they are active and contribute to processing and regulating synaptic information. We hypothesize that considering astrocytes as an important player in tDCS effect instead of the direct effect on voltage membrane of neurons is closer to the reality of tDCS effect mechanism. This hypothesis is examined here based on the experimental evidence published so far, which indicates astroglia involvement in tDCS-induced activities and results of our proposed computational model.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Encéfalo , Humanos , Neuroglia , Plasticidade Neuronal , Neurônios
6.
Electromagn Biol Med ; 40(3): 361-374, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34043463

RESUMO

The present study aimed to select an effective Pulsed High Magnetic Field (PHMF) stimulation protocol that would induce the Blood-Brain Barrier's (BBB) reversible permeability to enhance brain-targeted drug delivery. PHMF was applied to the skull over the right hemisphere of 60 Wistar rats. The sham group contained other 10 rats that did not receive PHMF stimulation. The investigated parameters were repetition frequencies (0.25, 1, and 4 Hz as well as the effective low frequency combined with 10 Hz) and numbers of pulses in each train. Evans Blue Dye (EBD) uptake within the brain parenchyma was measured to select an effective PHMF stimulation protocol. BBB reversibility was evaluated by measuring EBD uptake and Gadobutrol retention, through MRI signal intensity enhancement, within brain parenchyma after exposure to the effective PHMF stimulation protocol at different time points including 0.5, 1, and 24 hours. The obtained results showed that the PHMF stimulation increased the BBB's reversible permeability; this increase was more significant for 28 pulses with 1 Hz frequency (P < .0001). Changes in EBD uptake and MRI signal intensity in the exposed side (right hemisphere) peaked within 0.5-1 hour and returned to normal levels 24 hours after exposure to the effective protocol of PHMF stimulation (28 pulses with 1 Hz frequency). The Contrast-Enhanced MRI (CE-MRI) signal intensity confirmed the changes in EBD concentration. PHMF stimulation can be used as an effective protocol for enhancing the permeability reversibly of BBB, hence considered a potential clinical approach to brain-targeted drug delivery.


Assuntos
Barreira Hematoencefálica , Preparações Farmacêuticas , Animais , Encéfalo/diagnóstico por imagem , Campos Magnéticos , Permeabilidade , Ratos , Ratos Wistar
7.
Electromagn Biol Med ; 40(3): 438-445, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-33977836

RESUMO

Cell membrane acts as a barrier to the entry of impermeable drugs into cells. Recent studies have suggested that using magnetic fields can enable molecules to overcome the cell membrane barrier. However, the mechanism of membrane permeabilization remains unclear. Therefore, we evaluated the increases in bleomycin (CT) uptake, a non-permanent chemotherapy agent, using high-pulsed magnetic fields and investigated whether endocytosis was involved in the process. This study exposed MCF-7 cells to magnetic fields (2.2 T strength, different number of 28 and 56 pulses, and frequency of 1 and 10 Hz) in order to investigate whether this approach could promote the cell-killing efficiency of bleomycin. The involvement of endocytosis as a possible mechanism was tested by exposing cells to three endocytosis inhibitors, namely chlorpromazine, genistein, and amiloride. Our results illustrated that magnetic fields, depending on their conditions, could induce different endocytosis pathways. In such conditions as 10 Hz-28 pulses, 10 Hz-56 pulses, and 1 Hz-56 pulse, clathrin-mediated endocytosis was observed. Moreover, macropinocytosis was induced by the 10 Hz magnetic field and caveolae-mediated endocytosis occurred in all the magnetic field conditions. The findings imply that high-pulsed magnetic fields generate different endocytosis pathways in the MCF-7 cells, thus increasing the efficiency of chemotherapy agents.


Assuntos
Cavéolas , Clatrina , Membrana Celular , Endocitose , Campos Magnéticos
8.
J Ultrasound ; 18(2): 165-71, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26191104

RESUMO

PURPOSE: Because the cytotoxic potential of hydrophilic drugs like bleomycin (BLM) is restricted by its low membrane permeability, the application of low-intensity ultrasound (US) on growing tumor cells enhances intracellular delivery of BLM after intratumoral administration, thereby potentiating its cytotoxicity. In the present study, the in vivo cell membrane permeability enhancement with US (1 MHz, 2, 5, and 10 min, ISPTA = 2 W/cm(2)) is compared with the murine model of breast adenocarcinoma in BALB/c mice. METHODS: Tumor induction was performed through a homograft surgery procedure. Mice were anesthetized before putting them in sonication situations. Sonications were done in an aquarium. Seven groups of the tumor-bearing mice, each consisting of eight mice, were sonicated without or after intratumoral injection of 0.1 ml BLM at different exposure times. The tumor volume was evaluated to assess the growth process by use of a digital caliper. RESULTS: The results show that the BLM control group has a significant difference with BLM plus 10 min US on day 2 (p < 0.05). There is a significant difference between 2- and 10-min sonication on days 8 and 10 also. The difference between the Only US group and the other groups except Sham US was significant too (p < 0.05). Significant differences were seen only between the BLM plus US groups with Sham US and Only US control groups. CONCLUSION: It has been concluded that for significant permeabilization of the cell membrane, sonication time for more than 10 min is required. Significant difference between the Only US and other groups indicates that US has a promoting effect on cell division procedure, in spite of the no-carcinogen effect of the US.

9.
Cell J ; 16(4): 560-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25685747

RESUMO

The effect of external magnetic and electric fields, in the range of electroporation and magnetoporation, on Lucifer Yellow (LY) fluorescence in the absence of cells is studied. Electric-field-induced quenching and magnetic field-induced increase are observed for fluorescence intensity of LY. Regard to the fact that the variation of field-induced fluorescence, even in the absence of cells, can be observed, the application of LY, as a marker, is debatable in electroporation and magnetoporation techniques.

10.
Neurol Sci ; 35(11): 1651-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25073696

RESUMO

The recorded EEG of some brain regions of patients such as attention deficit hyperactivity disorder (ADHD), depression and etc. are different in comparison to healthy people. The disease improves with modifying the patient EEG that this is the basis of neurofeedback training. The main disadvantage of neurofeedback training demands patient's collaborative and active participation during treatment sessions, while some of patients such as addicts, depressed people and ADHD children cannot easily concentrate in direction of therapist's purpose. Furthermore, extremely low frequency magnetic fields (MFs) can affect brain signals and change them that in some cases lead to clinical effects. This report proposes if by locating small coils in desired region proceeds to local exposure of brain and happens in different frequencies or intensities and the effects of each MF in brain signals get analyzed then by knowing its effects we can make changes in patient voluntary without direct participation of patient in his/her brain signal changes. In the other words by changing type of the MF exposure and immediate record of brain signals we can fallow brain signals by observing the immediate record after exposure, with changes in the amplitude and the next exposure frequency, the therapist tries to direct the brain signal of desired region to the purpose. The possibility of approving this hypothesis in spite of contradictory effects about recovery or appearance of depression because of the MF and ability of local magnetic field exposures in changing of brain signals get reinforced to some extent.


Assuntos
Magnetoterapia/métodos , Transtornos Mentais/terapia , Neurorretroalimentação/métodos , Encéfalo , Eletroencefalografia , Campos Eletromagnéticos , Humanos , Magnetoterapia/tendências
11.
Neurol Sci ; 34(11): 1897-903, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23546991

RESUMO

In the current study we investigated the effect of repetitive transcranial magnetic stimulation (rTMS) at different frequencies on chemical kindling in rats. Chemical kindling was induced by injection of pentylenetetrazol (PTZ; 45 mg/kg) at the intervals of 48 h between the injections. In the first experiment, effect of 0.25, 1 and 5 Hz rTMS (four trains of 4 s at motor threshold intensity) on kindling acquisition was investigated. In the second experiment, the stability of rTMS effects was checked in animals of the first experiment during a follow-up period of 2 weeks. Animals received a single dose of PTZ at 7th and 14th day after the last PTZ injection (12th injection) and their seizure parameters were recorded. Obtained results showed that application of rTMS at the frequencies of 0.25 and 1 Hz had anticonvulsant effect and decreased the PTZ kindling acquisition. However, when applied at the frequency of 5 Hz, it had an increasing effect on PTZ kindling rate. During the follow-up study, the seizure severity increased in animals treated with 0.25 Hz rTMS (and somehow in animals treated with 1 Hz rTMS), but did not change in animals treated with 5 Hz rTMS compared to the 12th PTZ injection. Our results showed that rTMS application may have an anticonvulsant effect during chemical kindling acquisition at very low frequency (0.25 Hz) and can increase the seizure severity at high frequency (5 Hz). However, during follow-up, the anticonvulsant effects of rTMS may be converted to proconvulsive effects.


Assuntos
Excitação Neurológica , Convulsões/fisiopatologia , Estimulação Magnética Transcraniana , Animais , Masculino , Pentilenotetrazol , Ratos , Ratos Wistar , Convulsões/induzido quimicamente
12.
J Biomed Phys Eng ; 3(3): 87-92, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25505752

RESUMO

UNLABELLED: Propose: Standard electroporation and electrochemotherapy caused the endothelial cell permeability and reduction in tumor blood flow. The effects of low voltage and high frequency electroporation on the endothelial cells permeability and viability were expected. Therefore, the propose of present study was to evaluate the effect of electroporation with bleomycin or alone on viability and permeabilization of human Embryo microvascular endothelial (HUVEC) cell line. MATERIAL AND METHODS: The HUVEC cells were exposed to 4000 electric pulsed with 100µs duration, 50-150 v/cm with increment of 10 v/cm in 4, 5 and 6 kHz frequency (33 experimental groups) and then uptake and viability reduction was measured in each group. RESULTS: The results of this study demonstrated that electric pulses alone reduce the cell viability and with bleomycin significantly increases the toxicity to endothelial cells. CONCLUSION: Our data indicated that low voltage, high frequency ECT is highly cytotoxic for a HUVEC cell offers a possible effect of antivascular actions of this kind of electrochemotherapy.

13.
Radiol Oncol ; 46(2): 119-25, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23077448

RESUMO

BACKGROUND: The cell membrane acts as a barrier that hinders free entrance of most hydrophilic molecules into the cell. Due to numerous applications in medicine, biology and biotechnology, the introduction of impermeant molecules into biological cells has drawn considerable attention in the past years. One of the most famous methods in this field is electroporation, in which electric pulses with high intensity and short duration are applied to the cells. The aim of our study was to investigate the effect of time-varying magnetic field with different parameters on transmembrane molecular transport. MATERIALS AND METHODS: 'Moreover, a comparison was made between the uptake results due to magnetic pulse exposure and electroporation mediated uptake.' at the end of Background part. The Chinese hamster ovary (CHO) cells were exposed to magnetic pulses of 2.2 T peak strength and 250 µs duration delivered by Magstim stimulator and double 70 mm coil. Three different frequencies of 0.25, 1 and 10 Hz pulses with 112, 56 and 28 number of pulses were applied (altogether nine experimental groups) and Lucifer Yellow uptake was measured in each group. Moreover, maximum uptake of Lucifer Yellow obtained by magnetic pulses was compared to the measured uptake due to electroporation with typical parameters of 8 pulses of 100 µs, repetition frequency of 1 Hz and electric field intensities of 200 to 600 V/cm. RESULTS AND CONCLUSIONS: Our results show that time-varying magnetic field exposure increases transmembrane molecular transport and this uptake is greater for lower frequencies and larger number of pulses. Besides, the comparison shows that electroporation is more effective than pulsed magnetic field, but the observed uptake enhancement due to magnetic exposure is still considerable.

14.
Radiol Oncol ; 46(3): 226-32, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23077461

RESUMO

BACKGROUND: The aim of this study was to investigate the antitumor effectiveness of electrochemotherapy with cisplatin combined with suboptimal radiotherapy doses. Tumor radiosensitization was evaluated on large invasive ductal carcinoma tumors in Balb/C mice. MATERIALS AND METHODS: Tumors of an average volume of 630 mm(3) were treated with cisplatin, electric pulses, radiotherapy, electrochemotherapy, alone as well as in appropriate combinations. Tumors were irradiated with Cobalt-60 γ-rays at doses 3 Gy and 5 Gy in combination with electrochemotherapy using cisplatin. Controls included each of the treatments alone as well as the combination of the radiotherapy with electric pulses alone or with cisplatin alone. Antitumor effectiveness was evaluated by tumor growth delay, tumor-doubling time, inhibition ratio and the objective response rates. RESULTS: As anticipated, electrochemotherapy was more effective than the treatment with cisplatin alone or the application of the electric pulses alone. When treatments were combined with tumor irradiation at either 3 or 5 Gy, the combination with electrochemotherapy was more effective: at 5 Gy, 2 animals out of 8 were in complete remission 100 days later. In general the higher 5 Gy dose of γ-radiation was more effective than the lower one of 3 Gy. CONCLUSIONS: The results of our study demonstrate that irradiation doses, 3 Gy or 5 Gy, increase the antitumor effectiveness of electrochemotherapy with cisplatin on invasive ductal carcinoma tumors. Good antitumor results were achieved in experimental tumors with a size comparable to clinical lesions, demonstrating that this three-modality combined treatment is useful for the treatment of large lesions even at sub-optimal radiotherapy doses.

15.
Epilepsy Res ; 99(1-2): 69-77, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22071554

RESUMO

Low frequency stimulation (LFS) may be considered as a new potential therapy for drug-resistant epilepsy. However, the relation between LFS parameters and its anticonvulsant effects is not completely determined. In this study, the effect of some LFS parameters on its anticonvulsant action was investigated in rats. In all animals, stimulating and recording electrodes were implanted into the perforant path and dentate gyrus, respectively. In one group of animals, kindling stimulations were applied until rats achieved a fully kindled state. In other groups, different patterns of LFS were applied at the end of kindling stimulations during twenty consecutive days. In the first experiment the effect of LFS pulse numbers was investigated on its anticonvulsant action. Animals were divided randomly into three groups and 1, 4, and 8 packages of LFS (each pack contains 200 pulses, 0.1 ms pulse duration at 1 Hz) were applied five minutes after termination of kindling stimulations. Obtained results showed that 4 packages of LFS had the strongest anticonvulsant effects. Therefore, this pattern (4 packages) was used in the next experiment. In the second experiment, 4 packages of LFS were applied at intervals of 30 s and 30 min after termination of kindling stimulations. The strongest anticonvulsant effect was observed in the group received LFS at the interval of 30 s. Therefore, this pattern was selected for the third experiment. In the third experiment the effect of LFS at frequencies of 0.25 Hz and 5 Hz was investigated. The group of animals which received LFS at the frequency of 0.25 Hz showed somehow stronger anticonvulsant effect. The results indicate that different parameters of LFS have important role in induction of LFS anticonvulsant effects. Regarding this view, it seems that the slower LFS frequency and the shorter interval between LFS and kindling stimulations, the stronger anticonvulsant effect will be observed. But there is no direct relation between number of pulses and the magnitude of anticonvulsant effect of LFS.


Assuntos
Terapia por Estimulação Elétrica/métodos , Excitação Neurológica/fisiologia , Via Perfurante/fisiologia , Convulsões/prevenção & controle , Convulsões/fisiopatologia , Animais , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar
16.
Cell J ; 14(2): 110-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23508227

RESUMO

OBJECTIVE: In electrochemotherapy (ECT), there is an unpleasant sensation of muscle contraction when using a low frequency (1 Hz). Therefore, by increasing the pulse frequency above the tetanic frequency this painful sensation can be reduced. The aim of the present study is to compare the treatment efficiencies of low and high frequency ECT, and estimate the effect of its repeated sessions. MATERIALS AND METHODS: We transplanted invasive ductal carcinoma into the flanks of female Balb/c mice. ECT was performed on the mice by the use of 8 pulses, 1000 v/cm, of 100 µs duration at 1 Hz and 5 kHz repetition frequencies along with intra-tumoral injections of bleomycin. We also used this ECT protocol for the second therapy session six days after tumour regrowth. The effect of treatment was measured by calculating the tumor volumes for 24 days following treatment. Statistical analysis was performed with ANOVA. RESULTS: ECT at 1 Hz and 5 kHz pulse frequencies demonstrated significant inhibition of tumor growth, but after the first treatment the tumours began to regrow. Repetitive ECT sessions increased the curability of tumors up to 40% in the group treated by 1 Hz frequency and 60% in the group treated with 5 kHz frequency. CONCLUSION: Our results demonstrate that the effects of 1 Hz and 5 kHz pulse repetition frequencies are comparable for inhibited tumour growth. Repetitive treatment can improve the effectiveness of ECT.

17.
Comput Biol Med ; 39(12): 1073-82, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19880102

RESUMO

In the present paper a number of techniques were applied to determine the effects of epileptic seizure on spontaneous ongoing EEG. The idea is that seizure represents transitions of an epileptic brain from its normal (chaotic) state to an abnormal (more ordered) state. Some nonlinear measures including correlation dimension, maximum Lyapunov exponent and wavelet entropy and a graphical tool, named recurrence plot, as well as a novel technique that collects some statistics of the state space organization were used to characterize interictal, preictal and ictal states and derivate a phase transition. The novelty of this work includes of introducing new types of indicators base upon some nonlinear features besides of proposing a new feature of point distribution in phase space. Our results show that (1) these three states are separable in 3-D feature space of nonlinear measures with a gradual decrease of their quantity in seizure evolution, (2) strong rhythmicity, which manifests in recurrence plots and recurrence quantification analysis measures, appears in dynamic while having entered into seizure and (3) different volumes of state space are occupied during each phase of epileptic disorder. The significance of the work is that this information is a step into the detection of a preictal state and consequently is helpful in the prediction and control of epileptic seizures.


Assuntos
Diagnóstico por Computador/métodos , Eletroencefalografia/estatística & dados numéricos , Epilepsia/fisiopatologia , Adulto , Encéfalo/fisiopatologia , Biologia Computacional , Bases de Dados Factuais , Diagnóstico por Computador/estatística & dados numéricos , Epilepsia/diagnóstico , Epilepsia/etiologia , Lógica Fuzzy , Humanos , Modelos Neurológicos , Dinâmica não Linear , Recidiva
18.
Neurobiol Learn Mem ; 88(4): 387-92, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17768075

RESUMO

This study was planned to evaluate the effect of an exposure to magnetic fields on consolidation and retrieval of hippocampus dependent spatial memory using a water maze. In Experiments 1 and 2, rats were trained in a hidden version (spatial) of water maze task with two blocks of four trials. The retention of spatial memory was evaluated 48 h later. Exposure to a 50 Hz 8 mT, but not 2 mT magnetic fields for 20 min immediately after training impaired retention performance. The same time exposure shortly before retention testing had no effect. In Experiment 3, rats were trained in a cued version of water maze with two blocks of four trials. Exposure to magnetic field at 8 mT for 20 min immediately after training did not impair retention performance. These findings indicate that acute exposure to a 50 Hz magnetic field at 8 mT for short time can impair consolidation of spatial memory.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Hipocampo/fisiologia , Aprendizagem em Labirinto/fisiologia , Percepção Espacial/fisiologia , Comportamento Espacial/fisiologia , Análise de Variância , Animais , Estimulação Elétrica/instrumentação , Estimulação Elétrica/métodos , Hipocampo/efeitos da radiação , Masculino , Aprendizagem em Labirinto/efeitos da radiação , Ratos , Ratos Wistar , Retenção Psicológica/fisiologia , Retenção Psicológica/efeitos da radiação , Percepção Espacial/efeitos da radiação , Comportamento Espacial/efeitos da radiação , Estatísticas não Paramétricas
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