Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Proc Natl Acad Sci U S A ; 120(5): e2210698120, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36696442

RESUMO

Sharp-wave ripples (SWRs) are highly synchronous neuronal activity events. They have been predominantly observed in the hippocampus during offline states such as pause in exploration, slow-wave sleep, and quiescent wakefulness. SWRs have been linked to memory consolidation, spatial navigation, and spatial decision-making. Recently, SWRs have been reported during visual search, a form of remote spatial exploration, in macaque hippocampus. However, the association between SWRs and multiple forms of awake conscious and goal-directed behavior is unknown. We report that ripple activity occurs in macaque visual areas V1 and V4 during focused spatial attention. The occurrence of ripples is modulated by stimulus characteristics, increased by attention toward the receptive field, and by the size of the attentional focus. During attention cued to the receptive field, the monkey's reaction time in detecting behaviorally relevant events was reduced by ripples. These results show that ripple activity is not limited to hippocampal activity during offline states, rather they occur in the neocortex during active attentive states and vigilance behaviors.


Assuntos
Macaca , Neocórtex , Animais , Hipocampo/fisiologia , Vigília/fisiologia , Sono/fisiologia
2.
Behav Res Methods ; 55(1): 143-150, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35297015

RESUMO

Facial expressions play an essential role in social interactions. Databases of face images have furnished theories of emotion perception, as well as having applications in other disciplines such as facial recognition technology. However, the faces of many ethnicities remain largely underrepresented in the existing face databases, which can impact the generalizability of the theories and technologies developed based on them. Here, we present the first survey-validated database of Iranian faces. It consists of 248 images from 40 Iranian individuals portraying six emotional expressions-anger, sadness, fear, disgust, happiness, and surprise-as well as the neutral state. The photos were taken in a studio setting, following the common scenarios of emotion induction, and controlling for conditions of lighting, camera setup, and the model's head posture. An evaluation survey confirmed high agreement between the models' intended expressions and the raters' perception of them. The database is freely available online for academic research purposes.


Assuntos
Emoções , Expressão Facial , Humanos , Irã (Geográfico) , Felicidade , Ira
3.
J Stroke Cerebrovasc Dis ; 28(11): 104296, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31395425

RESUMO

OBJECTIVES: This study was designed to investigate the effect of prism adaptation (PA) combined with continuous theta-burst transcranial magnetic stimulation (cTBS) on the neglect recovery of stroke patients with unilateral neglect. METHODS: A total of 14 stroke patients with unilateral neglect were randomly assigned to 2 groups including an intervention group undergone PA combined with cTBS over the left intact parietal cortex and a control group. PA combined with sham cTBS was perfomed for 2 weeks in 10 daily sessions. Before and after the intervention, patients were evaluated for visuospatial neglect measured using the Star Cancellation Test (SCT), Line Bisection Task (LBT), Figure Copying Test, and Clock Drawing Task. Neurological function was evaluated using the Modified Rankin Scale (MRS). RESULTS: Both groups (PA alone and PA+ cTBS) showed improvement in their neglected symptoms (measured by SCT, LBT, Figure Copying Test, and Clock Drawing Task), and in their disability in the neurological function (measured by MRS) (P< .05). CONCLUSIONS: The results of the present study showed that, transcranial magnetic stimulation did not increase the effect of PA on neglect symptoms in stroke patients.


Assuntos
Agnosia/reabilitação , Ritmo beta , Encéfalo/fisiopatologia , Óculos , Reabilitação do Acidente Vascular Cerebral/instrumentação , Acidente Vascular Cerebral/terapia , Estimulação Magnética Transcraniana , Visão Ocular , Percepção Visual , Idoso , Agnosia/diagnóstico , Agnosia/fisiopatologia , Agnosia/psicologia , Terapia Combinada , Avaliação da Deficiência , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Projetos Piloto , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/psicologia , Reabilitação do Acidente Vascular Cerebral/efeitos adversos , Fatores de Tempo , Estimulação Magnética Transcraniana/efeitos adversos , Resultado do Tratamento
4.
Ann Nutr Metab ; 69(3-4): 181-189, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27855393

RESUMO

BACKGROUND/AIM: Existing evidence points to an altered status of iron metabolism in obesity. We aimed to investigate whether central obesity is independently associated with estimated liver iron content (liver T2* value) in general population that used the noninvasive assessment method by MRI. METHODS: The study was carried out on 200 subjects randomly selected from the Golestan Cohort Study who underwent abdominal MRI. Quantitative T2* maps of entire cross-sectional area of liver were calculated using a semi-automated software for estimating the levels of iron content. Segmentation and calculation of visceral (VFA) and subcutaneous fat area (SFA) were also performed. RESULTS: There was no significant difference in mean liver T2* values between obese (body mass index, BMI >30 kg/m2) and non-obese (BMI ≤30 kg/m2) subjects. After controlling for other covariates, no statistically significant association was detected between liver T2* values and VFA, SFA and VFA/SFA ratio. The drop in the relative signal intensity as an indicator of steatosis and serum ferritin predicted liver T2* values that almost had the same strength (standardized ß of -0.41 and -0.41, respectively). CONCLUSIONS: Central obesity indices are not correlated with estimated liver iron content by MRI. Hepatic steatosis and serum ferritin seem to be the best predictors of hepatic T2* value. Since central obesity indices were not direct predictors of hepatic T2* value after the adjustment for confounding factors, it is possible that lipid accumulation in the liver locally, but not systematically, influences hepatic iron metabolism.


Assuntos
Ferro/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Idoso , Estudos de Coortes , Feminino , Ferritinas/sangue , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Gordura Intra-Abdominal/metabolismo , Ferro/sangue , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Obesidade/complicações , Obesidade/diagnóstico por imagem , Gordura Subcutânea/diagnóstico por imagem , Gordura Subcutânea/metabolismo
5.
J Sleep Res ; 24(5): 518-25, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26014344

RESUMO

Recent evidence suggests that lack of slow-wave activity may play a fundamental role in the pathogenesis of insomnia. Pharmacological approaches and brain stimulation techniques have recently offered solutions for increasing slow-wave activity during sleep. We used slow (0.75 Hz) oscillatory transcranial direct current stimulation during stage 2 of non-rapid eye movement sleeping insomnia patients for resonating their brain waves to the frequency of sleep slow-wave. Six patients diagnosed with either sleep maintenance or non-restorative sleep insomnia entered the study. After 1 night of adaptation and 1 night of baseline polysomnography, patients randomly received sham or real stimulation on the third and fourth night of the experiment. Our preliminary results show that after termination of stimulations (sham or real), slow oscillatory transcranial direct current stimulation increased the duration of stage 3 of non-rapid eye movement sleep by 33 ± 26 min (P = 0.026), and decreased stage 1 of non-rapid eye movement sleep duration by 22 ± 17.7 min (P = 0.028), compared with sham. Slow oscillatory transcranial direct current stimulation decreased stage 1 of non-rapid eye movement sleep and wake time after sleep-onset durations, together, by 55.4 ± 51 min (P = 0.045). Slow oscillatory transcranial direct current stimulation also increased sleep efficiency by 9 ± 7% (P = 0.026), and probability of transition from stage 2 to stage 3 of non-rapid eye movement sleep by 20 ± 17.8% (P = 0.04). Meanwhile, slow oscillatory transcranial direct current stimulation decreased transitions from stage 2 of non-rapid eye movement sleep to wake by 12 ± 6.7% (P = 0.007). Our preliminary results suggest a sleep-stabilizing role for the intervention, which may mimic the effect of sleep slow-wave-enhancing drugs.


Assuntos
Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Distúrbios do Início e da Manutenção do Sono/terapia , Sono/fisiologia , Estimulação Transcraniana por Corrente Contínua , Adulto , Ondas Encefálicas/fisiologia , Doença Crônica/terapia , Feminino , Humanos , Masculino , Projetos Piloto , Polissonografia
6.
Basic Clin Neurosci ; 13(4): 455-463, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561232

RESUMO

Introduction: This study aims to investigate the attentional bias toward drug-related stimuli along with subjective craving after encountering such stimuli in methamphetamine users. Studies of cue reactivity have confirmed a bias in attention and gaze toward drug-related stimuli for most substances; however, methamphetamine drugs are less studied through a direct measure, such as eye tracking. Methods: A total of 30 male subjects in the case group (methamphetamine users) and 36 subjects in the control group (no prior drug use) participated in this study. The participant's eye movement data were collected while they were viewing pairs of drug-related and non-drug images in a dot-probe paradigm. Craving was assessed via a self-report questionnaire on a scale of 0 to 10 before and after the psychophysical task. Results: The analysis of eye-movement data showed a meaningful gaze bias toward cue images (drug-related) in the case group. Additionally, the gaze duration on cue images was significantly higher in the case group, in contrast to the control group. The same effect was observed in analyzing the dot-probe task; that is, the mean reaction time to a probe that replaced a cue image was significantly lower. The mean of the first-fixation measure in the control group was not significantly higher than chance; however, the percentage of the first-fixation on cue images in the drug users was meaningfully biased. Reported craving was significantly greater after performing the task compared to before. Conclusion: Our results indicated an attentional bias toward drug-related cues in methamphetamine users as well as subjective craving after encountering such cues. Highlights: The gaze duration on cue images was significantly higher in methamphetamine users.The mean reaction time to a probe that replaced a cue image was significantly lower in methamphetamine users compared to the control group.The mean of the first-fixation measure in the case group was significantly better than chance.Craving was reported to be significantly greater after performing the task. Plain Language Summary: Substance users tend to focus on the stimuli associated with substances. This is known as attention bias. Attention bias leads to increased craving. Attention bias for various substances has been previously reported; however, methamphetamine attention bias has not been evaluated so far. In this study, we measured the attention bias toward stimuli related to methamphetamine in methamphetamine users and control subjects with direct (eye tracking) and indirect (dot probe paradigm) methods. In addition, we measured the number of cravings in the case group. Our results confirmed the bias in attention toward methamphetamine-related stimuli in the case group compared to the control group.

7.
Iran J Med Sci ; 36(3): 154-66, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23358382

RESUMO

Glycation is a protein modification, which results in a change in a protein structure. Glycation is believed to be the etiology of various age-related diseases such as diabetes mellitus and Alzheimer's disease (AD). Activation of microglia and resident macrophages in the brain by glycated proteins with subsequent oxidative stress and cytokine release may be an important factor in the progression of AD. It is also suggested that interaction between an advanced glycation end product (AGE) and its receptor (RAGE) results in glial activation as well as cytokine release and reactive oxygen species release. The use of antioxidants, receptor mediated compounds and reactive oxygen species scavenging enzyme produce an opportunity to intervene with AGE-RAGE signaling pathway, and thereby to slow down the progression of aging-related diseases.

8.
Trials ; 22(1): 413, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34167566

RESUMO

BACKGROUND: Self-management of hypertension is of great significance given its increasing incidence and its associated disabilities. In view of the increased use of mobile health in medicine, the present study evaluated the effect of a self-management application on patient adherence to hypertension treatment. METHODS: This clinical trial was performed on 120 hypertensive patients who were provided with a mobile intervention for 8 weeks and followed up until the 24th week. Data on the primary outcome (adherence to treatment) and secondary outcomes (adherence to the DASH diet, regular monitoring of blood pressure, and physical activity) were collected using a questionnaire and a mobile application, respectively. The inter-group change difference over time was analyzed using repeated measures ANOVA (general linear model). RESULTS: The treatment adherence score increased by an average of 5.9 (95% CI 5.0-6.7) in the intervention group compared to the control group. The scores of "adherence to the low-fat and low-salt diet plans" were 1.7 (95% CI 1.3-2.1) and 1.5 (95% CI 1.2-1.9), respectively. Moreover, moderate physical activity increased to 100.0 min (95% CI 61.7-138.3) per week in the intervention group. CONCLUSION: The treatment and control of blood pressure require a multifaceted approach given its complexity and multifactorial nature. Considering the widespread use of smartphones, mHealth interventions can be effective in self-management and better patient adherence to treatments. Our results showed that this application can be used as a successful tool for hypertension self-management in patients attending public hospitals in developing countries. TRIAL REGISTRATION: Iran Randomized Clinical Trial Center IRCT2015111712211N2 . Registered on 1 January 2016.


Assuntos
Hipertensão , Aplicativos Móveis , Autogestão , Pressão Sanguínea , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Irã (Geográfico) , Adesão à Medicação
9.
Ophthalmic Physiol Opt ; 30(5): 626-31, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20883347

RESUMO

The chemical and physical properties of objects provide them with specific surface patterns of color and texture. Endogenous and exogenous forces alter these colors and patterns over time. The ability to identify these changes can have great utility in judging the state and history of objects. To evaluate the role of color cues in this process, we used images of 26 materials undergoing real changes. Observers were asked to identify materials and types of changes for color and gray-scale images. The images were shown in three sets; one image of the surface, two images of the same surface before and after a natural change, and image sequences of the time-varying appearance. The presence of color cues improved performance in all conditions. Identification of materials improved if observers saw two states of the material, but the complete image sequence did not improve performance.


Assuntos
Percepção de Cores/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Sinais (Psicologia) , Humanos , Estimulação Luminosa/métodos , Psicofísica , Propriedades de Superfície
10.
Comput Biol Med ; 117: 103596, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32072973

RESUMO

BACKGROUND AND OBJECTIVE: Despite the widespread prevalence of Multiple Sclerosis (MS), the study of brain interactions is still poorly understood. Moreover, there has always been a great need to automate the MS diagnosis procedure to eliminate the evaluation errors thereby improving its consistency and reliability. To address these issues, in this work, we proposed a robust pattern recognition algorithm as a computer-aided diagnosis system. This method is based on calculating the pairwise phase-synchrony of EEG recordings during a visual task. Initially, the bivariate empirical mode decomposition (BEMD) was applied to extract the intrinsic mode functions (IMFs). The phases of these IMFs were then obtained using the Hilbert transform to be utilized in the mean phase coherence (MPC), a measure for phase-synchrony calculation. After the construction of the feature space using MPC values, the ReliefF algorithm was applied for dimension reduction. Finally, the best distinguishing features were input to a k-nearest neighbor (KNN) classifier. The results revealed a higher level of network synchronization in the posterior regions of the brain and desynchronization in the anterior regions among the MS group as compared with the normal subjects. In the validation phase, the leave-one-subject-out cross-validation (LOOCV) method was used to assess the validity of the proposed algorithm. We achieved an accuracy, sensitivity, and specificity of 93.09%, 91.07%, and 95.24% for red-green, 90.44%, 88.39%, and 92.62% for luminance, and 87.44%, 87.05%, and 87.86% for blue-yellow tasks, respectively. The experimental results demonstrated the reliability of the presented method to be generalized in the field of automated MS diagnosis systems.


Assuntos
Esclerose Múltipla , Algoritmos , Diagnóstico por Computador , Eletroencefalografia , Humanos , Esclerose Múltipla/diagnóstico , Reprodutibilidade dos Testes
11.
Addict Health ; 12(2): 140-158, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32782736

RESUMO

Recent studies have revealed a growing number of patients affected by opioid use disorders (OUDs). Comorbid disorders are suspected to increase the risk of opioid-related adverse effects or treatment failure. The correlation of opioid use with sleep disturbances has been reported in many different studies and suggested to be linked to the brain regions involved in reward processing. This narrative review was intended to discuss the most recent developments in our understanding of the intricate interaction between sleep disturbance and OUD. In addition, in this study, the effects of sleep problems on the occurrence of unpleasant consequences in addiction management, such as craving and relapse in OCD patients, were highlighted. It has been shown that drug use may trigger the induction of sleep disturbances, and those suffering from difficulties in sleeping are prone to relapse to drug use, including opioids. Moreover, pharmaceutical sleep aids are likely to interfere with opiate use.

12.
J Vis ; 9(2): 3.1-12, 2009 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-19271913

RESUMO

It has recently been shown that the visual system is more sensitive to uniform color and/or luminance changes applied to raw compared to phase-scrambled images of natural scenes (A. Yoonessi & F. A. A. Kingdom, 2008). Here we consider whether the mechanisms responsible for the differential sensitivity operate before or after the point at which the signals from the two eyes are combined. Knowing this should help determine the types of nonlinearities responsible. Thresholds for detecting uniform color transformations applied to raw and phase-scrambled natural scenes were measured under two conditions: monocular, in which the discriminand pairs were placed side by side, and dichoptic, in which they were dichoptically superimposed. Subjects were required to select the pair of images that were transformed from two pairs of images in which the other pair was untransformed. In the dichoptic condition, the transformed image pair was identifiable by its lustrous appearance. In line with our previous findings, thresholds in the monocular condition were higher for the phase-scrambled compared to raw scenes. However in the dichoptic condition there was no significant difference between raw and phase-scrambled thresholds, suggesting that the differential sensitivity was mediated by mechanisms lying beyond the point of binocular combination. It is suggested that cortical neurons sensitive to edges but suppressed by neighboring texture might be responsible for the higher sensitivity to transformations applied to raw compared to phase-scrambled images of natural scenes.


Assuntos
Percepção de Cores/fisiologia , Limiar Sensorial , Visão Binocular/fisiologia , Adulto , Humanos , Masculino , Natureza , Psicometria
13.
Front Neurol ; 10: 483, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31133976

RESUMO

Antiepileptic drugs (AEDs) have repeatedly shown inconsistent and almost contradictory effects on the neurocognitive system, from substantial impairments in processing speed to the noticeable improvement in working memory and executive functioning. Previous studies have provided a novel insight into the cognitive improvement by bumetanide as a potential antiepileptic drug. Through the current investigation, we evaluated the longitudinal effects of bumetanide, an NKCC1 co-transporter antagonist, on the brain microstructural organization as a probable underlying component for cognitive performance. Microstructure assessment was completed using SPM for the whole brain assay and Freesurfer/TRACULA for the automatic probabilistic tractography analysis. Primary cognitive operations including selective attention and processing speed, working memory capacity and spatial memory were evaluated in 12 patients with a confirmed diagnosis of refractory epilepsy. Participants treated with bumetanide (2 mg/ day) in two divided doses as an adjuvant therapy to their regular AEDs for 6 months, which followed by the re-assessment of their cognitive functions and microstructural organizations. Seizure frequency reduced in eight patients which accompanied by white matter reconstruction; fractional anisotropy (FA) increased in the cingulum-cingulate gyrus (CCG), anterior thalamic radiation (ATR), and temporal part of the superior longitudinal fasciculus (SLFt) in correlation with the clinical response. The voxel-based analysis in responder patients revealed increased FA in the left hippocampus, right cerebellum, and right medial temporal lobe, while mean diffusivity (MD) values reduced in the right occipital lobe and cerebellum. Microstructural changes in SLFt and ATR accompanied by a reduction in the error rate in the spatial memory test. These primary results have provided preliminary evidence for the effect of bumetanide on cognitive functioning through microstructural changes in patients with drug-resistant epilepsy.

14.
Basic Clin Neurosci ; 9(2): 135-146, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29967673

RESUMO

INTRODUCTION: Transcranial Direct Current Stimulation (tDCS) has been used as a non-invasive method to increase the plasticity of brain. Growing evidence has shown several brain disorders such as depression, anxiety disorders, and chronic pain syndrome are improved following tDCS. In patients with Obsessive-Compulsive Disorder (OCD), increased brain rhythm activity particularly in the frontal lobe has been reported in several studies using Eectroencephalogram (EEG). To our knowledge, no research has been done on the effects of electrical stimulation on brain signals of patients with OCD. We measured the electrical activity of the brain using EEG in patients with OCD before and after tDCS and compared it to normal participants. METHODS: Eight patients with OCD (3 males) and 8 matched healthy controls were recruited. A 64-channel EEG was used to record a 5-min resting state before and after application of tDCS in both groups. The intervention of tDCS was applied for 15 minutes with 2 mA amplitude where anode was placed on the left Dorsolateral Prefrontal Cortex (DLPFC) and cathode on the right DLPFC. RESULTS: In line with previous studies, the results showed that the power of Delta frequency band in OCD patients are significantly higher than the normal group. Following anodal tDCS, hyperactivity in Delta and Theta bands declined in most channels, particularly in DLPFC (F3, F4) and became similar to normal signals pattern. The reduction in Delta band was significantly more than the other bands. CONCLUSION: Anodal tDCS over the left DLPFC significantly decreased the power of frequency bands of Delta and Theta in Patients with OCD. The pattern of EEG activity after tDCS became particularly similar to normal, so tDCS may have potential clinical application in these patients.

15.
Basic Clin Neurosci ; 8(6): 435-442, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29942427

RESUMO

INTRODUCTION: Tinnitus is one of the complex symptoms of hearing described as a phantom auditory sensation without any external stimulation. Due to the subjective nature of tinnitus, perception and discomfort of tinnitus vary among the patients. The main aim of this study is to investigate the effects of gender, age and the degree of hearing loss on discomfort due to tinnitus. METHODS: Eighteen patients with tinnitus, aged 21-72 years, (9 males and 9 females) were recruited. Tinnitus discomfort was investigated by Tinnitus Handicap Inventory (THI) questionnaire. Psychoacoustic assessments of tinnitus and auditory threshold assessments were evaluated using a 2-channel clinical audiometer. RESULTS: The results showed no significant correlation between THI scores with loudness matching (P=0.187), mean of auditory threshold (P=0.304), gender (P=0.93) and age (P=0.200). Also, no significant correlation was found between maximal level of hearing loss and pitch matching (P=0.208). CONCLUSION: The study findings suggests that tinnitus is not correlated with age, gender and hearing loss. Overall, tinnitus is a complicated clinical condition which its real impact and degree of discomfort are unclear. More investigation is needed to clarify the factors involving in tinnitus annoyance.

16.
Basic Clin Neurosci ; 8(4): 299-306, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29158880

RESUMO

INTRODUCTION: Mild Cognitive Impairment (MCI), a disorder of the elderly people, is difficult to diagnose and often progresses to Alzheimer Disease (AD). Temporal region is one of the initial areas, which gets impaired in the early stage of AD. Therefore, auditory cortical evoked potential could be a valuable neuromarker for detecting MCI and AD. METHODS: In this study, the thresholds of Auditory Steady-State Response (ASSR) to 40 Hz and 80 Hz were compared between Alzheimer Disease (AD), MCI, and control groups. A total of 42 patients (12 with AD, 15 with MCI, and 15 elderly normal controls) were tested for ASSR. Hearing thresholds at 500, 1000, and 2000 Hz in both ears with modulation rates of 40 and 80 Hz were obtained. RESULTS: Significant differences in normal subjects were observed in estimated ASSR thresholds with 2 modulation rates in 3 frequencies in both ears. However, the difference was significant only in 500 Hz in the MCI group, and no significant differences were observed in the AD group. In addition, significant differences were observed between the normal subjects and AD patients with regard to the estimated ASSR thresholds with 2 modulation rates and 3 frequencies in both ears. A significant difference was observed between the normal and MCI groups at 2000 Hz, too. An increase in estimated 40 Hz ASSR thresholds in patients with AD and MCI suggests neural changes in auditory cortex compared to that in normal ageing. CONCLUSION: Auditory threshold estimation with low and high modulation rates by ASSR test could be a potentially helpful test for detecting cognitive impairment.

17.
Prog Neuropsychopharmacol Biol Psychiatry ; 79(Pt B): 426-433, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28757160

RESUMO

Despite the worldwide use of tramadol, few studies have been conducted about its effects on memory and mitochondrial function, and controversial results have been reported. Recently, there has been an increasing interest in physical exercise as a protective approach to neuronal and cognitive impairments. Therefore, the aim of this study was to investigate the effects of physical exercise on spatial learning and memory and brain mitochondrial function in tramadol-treated rats. After completion of 2-week (short-term) and 4-week (long-term) treadmill exercise regimens, male Wistar rats received tramadol (20, 40, 80mg/kg/day) intraperitoneally for 30days. Then spatial learning and memory was assessed by Morris water maze test (MWM). Moreover, brain mitochondrial function was evaluated by determination of mitochondrial reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), mitochondrial swelling and cytochrome c release from mitochondria. Chronic administration of tramadol impaired spatial learning and memory as well as brain mitochondrial function as indicated by increased ROS level, MMP collapse, increased mitochondrial swelling and cytochrome c release from mitochondria. Conversely, treadmill exercise significantly attenuated the impairments of spatial learning and memory and brain mitochondrial dysfunction induced by tramadol. The results revealed that chronic tramadol treatment caused memory impairments through induction of brain mitochondrial dysfunction. Furthermore, pre-exposure to physical exercise markedly mitigated these impairments through its positive effects on brain mitochondrial function.


Assuntos
Terapia por Exercício , Aprendizagem em Labirinto/efeitos dos fármacos , Doenças Mitocondriais/induzido quimicamente , Doenças Mitocondriais/terapia , Aprendizagem Espacial/efeitos dos fármacos , Tramadol/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/fisiopatologia , Deficiências da Aprendizagem/induzido quimicamente , Deficiências da Aprendizagem/patologia , Deficiências da Aprendizagem/fisiopatologia , Deficiências da Aprendizagem/terapia , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/patologia , Transtornos da Memória/fisiopatologia , Transtornos da Memória/terapia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Doenças Mitocondriais/patologia , Doenças Mitocondriais/fisiopatologia , Atividade Motora/fisiologia , Entorpecentes/toxicidade , Síndromes Neurotóxicas/patologia , Síndromes Neurotóxicas/fisiopatologia , Síndromes Neurotóxicas/psicologia , Síndromes Neurotóxicas/terapia , Transtornos Relacionados ao Uso de Opioides/patologia , Transtornos Relacionados ao Uso de Opioides/fisiopatologia , Transtornos Relacionados ao Uso de Opioides/psicologia , Transtornos Relacionados ao Uso de Opioides/terapia , Distribuição Aleatória , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Aprendizagem Espacial/fisiologia
18.
Front Hum Neurosci ; 10: 630, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28018197

RESUMO

Humans are fast and accurate in categorizing complex natural images. It is, however, unclear what features of visual information are exploited by brain to perceive the images with such speed and accuracy. It has been shown that low-level contrast statistics of natural scenes can explain the variance of amplitude of event-related potentials (ERP) in response to rapidly presented images. In this study, we investigated the effect of these statistics on frequency content of ERPs. We recorded ERPs from human subjects, while they viewed natural images each presented for 70 ms. Our results showed that Weibull contrast statistics, as a biologically plausible model, explained the variance of ERPs the best, compared to other image statistics that we assessed. Our time-frequency analysis revealed a significant correlation between these statistics and ERPs' power within theta frequency band (~3-7 Hz). This is interesting, as theta band is believed to be involved in context updating and semantic encoding. This correlation became significant at ~110 ms after stimulus onset, and peaked at 138 ms. Our results show that not only the amplitude but also the frequency of neural responses can be modulated with low-level contrast statistics of natural images and highlights their potential role in scene perception.

19.
Basic Clin Neurosci ; 7(3): 221-30, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27563415

RESUMO

INTRODUCTION: Methamphetamine is a powerful psychostimulant that causes significant neurological impairments with long-lasting effects and has provoked serious international concerns about public health. Denial of drug abuse and drug craving are two important factors that make the diagnosis and treatment extremely challenging. Here, we present a novel and rapid noninvasive method with potential application for differentiation and monitoring methamphetamine abuse. METHODS: Visual stimuli comprised a series of images with neutral and methamphetamine-related content. A total of 10 methamphetamine abusers and 10 age-gender matched controls participated in the experiments. Event-related potentials (ERPs) were recorded and compared using a time window analysis method. The ERPs were divided into 19 time windows of 100 ms with 50 ms overlaps. The area of positive sections below each window was calculated to measure the differences between the two groups. RESULTS: Significant differences between two groups were observed from 250 to 500 ms (P300) in response to methamphetamine-related visual stimuli and 600 to 800 ms in response to neutral stimuli. CONCLUSION: This study presented a novel and noninvasive method based on neural correlates to discriminate healthy individuals from methamphetamine drug abusers. This method can be employed in treatment and monitoring of the methamphetamine abuse.

20.
Trials ; 17(1): 511, 2016 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-27769282

RESUMO

BACKGROUND: Hypertension is one of the most important and well-known risk factors for cardiovascular diseases. Unfortunately, in spite of effective treatments, adherence to the regular use of drugs and other nondrug treatments, such as lifestyle improvement, is often poor. This study evaluates the effectiveness of an educational, supportive intervention - in the form of a Blood Pressure Management Application (BPMAP) - on self-management in patients with primary hypertension on controlling the determinant factors of hypertension, and on adherence to treatment. METHODS/DESIGN: A two-arm, parallel-design randomized controlled clinical trial will be conducted on 30 to 60 year-old patients with primary hypertension who are attending the Tehran Heart Center. One hundred and thirty-two (132) patients will be randomly assigned to the intervention and control (usual method) groups. The most important inclusion criteria are, having primary hypertension and being pharmacologically treated for it, and not having developed the complications of hypertension, such as myocardial infarction, cerebral stroke and cardiac insufficiency. The participants should be able to read Persian and be able to use the application. The most important outcomes of the study include adherence to treatment, weight control, and regular monitoring of blood pressure which are assessed in the primary assessment (baseline data questionnaire) and again at the 8th and 24th weeks. The intervention is a mobile application that has capabilities such as reminders and scientific and supportive information. DISCUSSION: This application has been programmed to reduce many of the nonadherence factors of hypertension treatment. Therefore, the findings may contribute to a rise in adherence to treatment. If proven to have an appropriate impact, it may be extended for use in the national hypertension control plan. TRIAL REGISTRATION: This study was registered in the Iran Randomized Clinical Trial Center under the number IRCT2015111712211N2 on 1 January 2016.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Adesão à Medicação , Educação de Pacientes como Assunto , Autocuidado/métodos , Telemedicina/métodos , Adulto , Monitorização Ambulatorial da Pressão Arterial , Protocolos Clínicos , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Hipertensão/psicologia , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Aplicativos Móveis , Valor Preditivo dos Testes , Sistemas de Alerta , Projetos de Pesquisa , Fatores de Risco , Comportamento de Redução do Risco , Autocuidado/instrumentação , Smartphone , Inquéritos e Questionários , Telemedicina/instrumentação , Fatores de Tempo , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa