Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Brain Sci ; 14(4)2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38672027

RESUMO

This study aimed to investigate the effects of intranasal air-puffing on cognitive impairments and brain cortical activity following one night of partial sleep deprivation (PSD) in adults. A total of 26 healthy adults underwent the numerical Stroop test (NST) and electroencephalography (EEG) before and after one night of PSD. Following PSD, subjects in the treatment group (n = 13) received nasal air-puffs (5 Hz, 3 min) before beginning the NST and EEG recording. Administration of nasal air-puffs in the treatment group restored the PSD-induced increase in error rate and decrease in reaction time and missing rate in the NST. Intranasal air-puffs recovered the PSD-induced augmentation of delta and theta power and the reduction of beta and gamma power in the EEG, particularly in the frontal lobes. Intranasal air-puffing also almost reversed the PSD-induced decrease in EEG signal complexity. Furthermore, it had a restorative effect on PSD-induced alteration in intra-default mode network functional connectivity in the beta and gamma frequency bands. Rhythmic nasal air-puffing can mitigate acute PSD-induced impairments in cognitive functions. It exerts part of its ameliorating effect by restoring neuronal activity in cortical brain areas involved in cognitive processing.

2.
CNS Neurosci Ther ; 30(3): e14656, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38439573

RESUMO

AIMS: In this study, the anticonvulsant action of closed-loop, low-frequency deep brain stimulation (DBS) was investigated. In addition, the changes in brain rhythms and functional connectivity of the hippocampus and prefrontal cortex were evaluated. METHODS: Epilepsy was induced by pilocarpine in male Wistar rats. After the chronic phase, a tripolar electrode was implanted in the right ventral hippocampus and a monopolar electrode in medial prefrontal cortex (mPFC). Subjects' spontaneous seizure behaviors were observed in continuous video recording, while the local field potentials (LFPs) were recorded simultaneously. In addition, spatial memory was evaluated by the Barnes maze test. RESULTS: Applying hippocampal DBS, immediately after seizure detection in epileptic animals, reduced their seizure severity and duration, and improved their performance in Barnes maze test. DBS reduced the increment in power of delta, theta, and gamma waves in pre-ictal, ictal, and post-ictal periods. Meanwhile, DBS increased the post-ictal-to-pre-ictal ratio of theta band. DBS decreased delta and increased theta coherences, and also increased the post-ictal-to-pre-ictal ratio of coherence. In addition, DBS increased the hippocampal-mPFC coupling in pre-ictal period and decreased the coupling in the ictal and post-ictal periods. CONCLUSION: Applying closed-loop, low-frequency DBS at seizure onset reduced seizure severity and improved memory. In addition, the changes in power, coherence, and coupling of the LFP oscillations in the hippocampus and mPFC demonstrate low-frequency DBS efficacy as an antiepileptic treatment, returning LFPs to a seemingly non-seizure state in subjects that received DBS.


Assuntos
Epilepsia , Pilocarpina , Humanos , Masculino , Ratos , Animais , Pilocarpina/toxicidade , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/terapia , Anticonvulsivantes , Hipocampo , Aprendizagem em Labirinto
3.
J Photochem Photobiol B ; 252: 112852, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38330690

RESUMO

Infertility is such an important issue in society today. In some cases of male infertility, the main cause is oxidative stress and the presence of reactive oxygen species in the environment or in sperm cells. All current techniques that measure oxidative stress, including the nitroblue tetrazolium Test, DNA Fragmentation Index, Malondialdehyde, and Endz Test are qualitative and semi-quantitative. These methods do not have good sensitivity and specificity. Semen samples from 50 infertile patients and 10 normal individuals were collected. The samples were examined for laboratory routine tests according to the WHO 2010 protocol. Oxidative stress tests, including DFI, NBT, and MDA, were performed for these two groups. Bioluminescence inhibition assay was performed for detection of O2.- in semen samples by aequorin. The normal individuals showed significantly better semen parameters than the patient's group. Significantly lower O2.- levels were seen in the patient's group compared to normal individuals. The cut-off value of O2.- levels in normal individuals was determined to be 8 × 105 RLU/s with a sensitivity of 100% and a specificity of 100%. Infertile patients, despite having reduced quality of semen parameters, have high O2.- levels, and this causes the intensity of bioluminescence to be quenched in these people.


Assuntos
Infertilidade Masculina , Superóxidos , Humanos , Masculino , Superóxidos/metabolismo , Sêmen , Fragmentação do DNA , Motilidade dos Espermatozoides , Estresse Oxidativo/fisiologia , Infertilidade Masculina/diagnóstico , Espermatozoides/metabolismo
4.
Mol Brain ; 16(1): 77, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37950268

RESUMO

Optogenetics has revolutionised neuroscience research, but at the same time has brought a plethora of new variables to consider when designing an experiment with AAV-based targeted gene delivery. Some concerns have been raised regarding the impact of AAV injection volume and expression time in relation to longitudinal experimental designs. In this study, we investigated the efficiency of optically evoked post-synaptic responses in connection to two variables: the volume of the injected virus and the expression time of the virus. For this purpose, we expressed the blue-shifted ChR2, oChIEF, employing a widely used AAV vector delivery strategy. We found that the volume of the injected virus has a minimal impact on the efficiency of optically-evoked postsynaptic population responses. The expression time, on the other hand, has a pronounced effect, with a gradual reduction in the population responses beyond 4 weeks of expression. We strongly advise to monitor time-dependent expression profiles when planning or conducting long-term experiments that depend on successful and stable channelrhodopsin expression.


Assuntos
Terapia Genética , Vetores Genéticos , Channelrhodopsins/genética , Channelrhodopsins/metabolismo , Optogenética , Dependovirus/metabolismo
5.
J Med Signals Sens ; 13(4): 253-260, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37809015

RESUMO

Background: Optical coherence tomography (OCT) imaging significantly contributes to ophthalmology in the diagnosis of retinal disorders such as age-related macular degeneration and diabetic macular edema. Both diseases involve the abnormal accumulation of fluids, location, and volume, which is vitally informative in detecting the severity of the diseases. Automated and accurate fluid segmentation in OCT images could potentially improve the current clinical diagnosis. This becomes more important by considering the limitations of manual fluid segmentation as a time-consuming and subjective to error method. Methods: Deep learning techniques have been applied to various image processing tasks, and their performance has already been explored in the segmentation of fluids in OCTs. This article suggests a novel automated deep learning method utilizing the U-Net structure as the basis. The modifications consist of the application of transformers in the encoder path of the U-Net with the purpose of more concentrated feature extraction. Furthermore, a custom loss function is empirically tailored to efficiently incorporate proper loss functions to deal with the imbalance and noisy images. A weighted combination of Dice loss, focal Tversky loss, and weighted binary cross-entropy is employed. Results: Different metrics are calculated. The results show high accuracy (Dice coefficient of 95.52) and robustness of the proposed method in comparison to different methods after adding extra noise to the images (Dice coefficient of 92.79). Conclusions: The segmentation of fluid regions in retinal OCT images is critical because it assists clinicians in diagnosing macular edema and executing therapeutic operations more quickly. This study suggests a deep learning framework and novel loss function for automated fluid segmentation of retinal OCT images with excellent accuracy and rapid convergence result.

6.
Diagnostics (Basel) ; 13(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37370889

RESUMO

The retina is a thin, light-sensitive membrane with a multilayered structure found in the back of the eyeball. There are many types of retinal disorders. The two most prevalent retinal illnesses are Age-Related Macular Degeneration (AMD) and Diabetic Macular Edema (DME). Optical Coherence Tomography (OCT) is a vital retinal imaging technology. X-lets (such as curvelet, DTCWT, contourlet, etc.) have several benefits in image processing and analysis. They can capture both local and non-local features of an image simultaneously. The aim of this paper is to propose an optimal deep learning architecture based on sparse basis functions for the automated segmentation of cystic areas in OCT images. Different X-let transforms were used to produce different network inputs, including curvelet, Dual-Tree Complex Wavelet Transform (DTCWT), circlet, and contourlet. Additionally, three different combinations of these transforms are suggested to achieve more accurate segmentation results. Various metrics, including Dice coefficient, sensitivity, false positive ratio, Jaccard index, and qualitative results, were evaluated to find the optimal networks and combinations of the X-let's sub-bands. The proposed network was tested on both original and noisy datasets. The results show the following facts: (1) contourlet achieves the optimal results between different combinations; (2) the five-channel decomposition using high-pass sub-bands of contourlet transform achieves the best performance; and (3) the five-channel decomposition using high-pass sub-bands formations out-performs the state-of-the-art methods, especially in the noisy dataset. The proposed method has the potential to improve the accuracy and speed of the segmentation process in clinical settings, facilitating the diagnosis and treatment of retinal diseases.

7.
Sci Rep ; 13(1): 6520, 2023 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-37085688

RESUMO

Pharmacoresistant temporal lobe epilepsy affects millions of people around the world with uncontrolled seizures and comorbidities, like anxiety, being the most problematic aspects calling for novel therapies. The intrahippocampal kainic acid model of temporal lobe epilepsy is an appropriate rodent model to evaluate the effects of novel interventions, including glycolysis inhibition, on epilepsy-induced alterations. Here, we investigated kainic acid-induced changes in the dorsal hippocampus (dHPC) and basolateral amygdala (BLA) circuit and the efficiency of a glycolysis inhibitor, 2-deoxy D-glucose (2-DG), in resetting such alterations using simultaneous local field potentials (LFP) recording and elevated zero-maze test. dHPC theta and gamma powers were lower in epileptic groups, both in the baseline and anxiogenic conditions. BLA theta power was higher in baseline condition while it was lower in anxiogenic condition in epileptic animals and 2-DG could reverse it. dHPC-BLA coherence was altered only in anxiogenic condition and 2-DG could reverse it only in gamma frequency. This coherence was significantly correlated with the time in which the animals exposed themselves to the anxiogenic condition. Further, theta-gamma phase-locking was lower in epileptic groups in the dHPC-BLA circuit and 2-DG could considerably increase it.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Epilepsia do Lobo Temporal , Epilepsia , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Ácido Caínico , Ansiedade , Hipocampo , Epilepsia/induzido quimicamente , Glicólise
8.
Life Sci ; 315: 121373, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36621536

RESUMO

AIMS: Allergic asthma is associated with anxiety-related behaviors, leading to poor quality of life. Previous studies mainly described the neuropathophysiology of asthma-induced anxiety. However, the effects of corticosteroids, the most common anti-inflammatory agents for asthma treatment, on the neurophysiological foundations of allergic asthma-induced anxiety are unexplored. MAIN METHODS: Here, we evaluated lung and brain inflammation as well as anxiety in an animal model of allergic asthma pretreated with inhaled fluticasone propionate. Furthermore, to define the neurophysiological bases of these conditions, we studied the medial prefrontal cortex (mPFC)-amygdala circuit, which is previously shown to accompany asthma-induced anxiety. KEY FINDINGS: Our data showed that allergen induces anxiety, mPFC and amygdala inflammation, as well as disruptions in the local and long-range oscillatory activities within the mPFC-amygdala circuit. Interestingly, we observed a roughly consistent trend of changes with inhaled fluticasone pretreatment. Namely, the asthma-induced behavioral, inflammatory, and neurophysiological changes were partly, but not totally, prevented by inhaled fluticasone pretreatment. SIGNIFICANCE: We suggest that early treatment of asthmatic patients with inhaled corticosteroids improves mPFC-amygdala circuit function by attenuating neuroinflammation leading to reduced anxiety. These findings could lead clinical guidelines of asthma to consider the neuropsychiatric disorders of patients in treatment recommendations.


Assuntos
Asma , Qualidade de Vida , Animais , Androstadienos/efeitos adversos , Asma/induzido quimicamente , Fluticasona/uso terapêutico , Córtex Pré-Frontal , Ansiedade/tratamento farmacológico , Tonsila do Cerebelo , Corticosteroides/uso terapêutico , Administração por Inalação
9.
Respir Physiol Neurobiol ; 307: 103981, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36330894

RESUMO

BACKGROUND AND OBJECTIVES: Default mode network (DMN) is a principal network that is more active at the baseline functional state of consciousness and spontaneous brain activity. Nasal breathing beyond the oxygen supply, entrained brain oscillations in widespread brain regions. Consistent with the important role of nasal breathing on neural oscillation for brain function, here we aimed to evaluate respiration entrained DMN rhythms. MATERIALS AND METHODS: Using electroencephalography (EEG), we assessed the power spectral density and connectivity in DMN during the resting state among a group of sixteen healthy during three successive sessions. In addition to DMN, synchrony of the signal over the widespread cortical regions including somatosensory areas was investigated. Signal acquisition sessions consist of three times including nasal breathing, oral breathing, and nasal air-puff state that odorless air was puffed using a nasal cannula via an electrical valve (open duration of 630 ms) with a frequency of 0.2 Hz while subjects spontaneously breath orally. RESULTS: Our analyses demonstrated that nasal airflow, during both nasal breathing and nasal air-puff states, enhanced the power and connectivity of DMN regions specially at higher frequency bands, particularly gamma ranges. Enhancement in brain areas activity and connectivity including DMN and somatosensory due to the nasal airflow were not affected even in the condition that subjects were not attending to the nasal air-puff. CONCLUSIONS: Nasal airflow promotes brain oscillations, particularly at the range of gamma that is very essential for higher brain functions.


Assuntos
Rede de Modo Padrão , Eletroencefalografia , Humanos , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Estado de Consciência , Imageamento por Ressonância Magnética
10.
Neurochem Res ; 48(1): 210-228, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36064822

RESUMO

Temporal lobe epilepsy is the most drug-resistant type with the highest incidence among the other focal epilepsies. Metabolic manipulations are of great interest among others, glycolysis inhibitors like 2-deoxy D-glucose (2-DG) being the most promising intervention. Here, we sought to investigate the effects of 2-DG treatment on cellular and circuit level electrophysiological properties using patch-clamp and local field potentials recordings and behavioral alterations such as depression and anxiety behaviors, and changes in nitric oxide signaling in the intrahippocampal kainic acid model. We found that epileptic animals were less anxious, more depressed, with more locomotion activity. Interestingly, by masking the effect of increased locomotor activity on the parameters of the zero-maze test, no altered anxiety behavior was noted in epileptic animals. However, 2-DG could partially reverse the behavioral changes induced by kainic acid. The findings also showed that 2-DG treatment partially suppresses cellular level alterations while failing to reverse circuit-level changes resulting from kainic acid injection. Analysis of NADPH-diaphorase positive neurons in the CA1 area of the hippocampus revealed that the number of positive neurons was significantly reduced in dorsal CA1 of the epileptic animals and 2-DG treatment did not affect the diminishing effect of kainic acid on NADPH-d+ neurons in the CA1 area. In the control group receiving 2-DG, however, an augmented NADPH-d+ cell number was noted. These data suggest that 2-DG cannot suppress epileptiform activity at the circuit-level in this model of epilepsy and therefore, may fail to control the seizures in temporal lobe epilepsy cases.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Animais , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/prevenção & controle , Ácido Caínico/toxicidade , NADPH Desidrogenase/metabolismo , NADPH Desidrogenase/farmacologia , Glucose/metabolismo , NADP/metabolismo , Hipocampo/metabolismo , Epilepsia/metabolismo , Neurônios/metabolismo , Desoxiglucose/farmacologia , Desoxiglucose/uso terapêutico , Glicólise , Modelos Animais de Doenças
11.
J Physiol Sci ; 72(1): 9, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35468718

RESUMO

Neural oscillations synchronize the activity of brain regions during cognitive functions, such as spatial working memory. Olfactory bulb (OB) oscillations are ubiquitous rhythms that can modulate neocortical and limbic regions. However, the functional connectivity between the OB and areas contributing to spatial working memory, such as the ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC), is less understood. Hence, we investigated functional interaction between OB and the vHPC-mPFC circuit during the spatial working memory performance in rats. To this end, we analyzed the simultaneously recorded local field potentials from OB, vHPC, and mPFC when rats explored the Y-maze and compared the brain activities of correct trials vs. wrong trials. We found that coupling between the vHPC and mPFC was augmented during correct trials. The enhanced coherence of OB activity with the vHPC-mPFC circuit at delta (< 4 Hz) and gamma (50-80 Hz) ranges were observed during correct trials. The cross-frequency analysis revealed that the OB delta phase increased the mPFC gamma power within corrected trials, indicating a modulatory role of OB oscillations on mPFC activity during correct trials. Moreover, the correlation between OB oscillations and the vHPC-mPFC circuit was increased at the delta range during correct trials, exhibiting enhanced synchronized activity of these regions during the cognitive task. We demonstrated a functional engagement of OB connectivity with the vHPC-mPFC circuit during spatial working memory task performance.


Assuntos
Memória de Curto Prazo , Bulbo Olfatório , Animais , Cognição , Hipocampo , Córtex Pré-Frontal , Ratos , Memória Espacial
12.
Sci Rep ; 12(1): 4394, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35292712

RESUMO

Neural synchrony in brain circuits is the mainstay of cognition, including memory processes. Alzheimer's disease (AD) is a progressive neurodegenerative disorder that disrupts neural synchrony in specific circuits, associated with memory dysfunction before a substantial neural loss. Recognition memory impairment is a prominent cognitive symptom in the early stages of AD. The entorhinal-hippocampal circuit is critically engaged in recognition memory and is known as one of the earliest circuits involved due to AD pathology. Notably, the olfactory bulb is closely connected with the entorhinal-hippocampal circuit and is suggested as one of the earliest regions affected by AD. Therefore, we recorded simultaneous local field potential from the olfactory bulb (OB), entorhinal cortex (EC), and dorsal hippocampus (dHPC) to explore the functional connectivity in the OB-EC-dHPC circuit during novel object recognition (NOR) task performance in a rat model of AD. Animals that received amyloid-beta (Aß) showed a significant impairment in task performance and a marked reduction in OB survived cells. We revealed that Aß reduced coherence and synchrony in the OB-EC-dHPC circuit at theta and gamma bands during NOR performance. Importantly, our results exhibit that disrupted functional connectivity in the OB-EC-dHPC circuit was correlated with impaired recognition memory induced by Aß. These findings can elucidate dynamic changes in neural activities underlying AD, helping to find novel diagnostic and therapeutic targets.


Assuntos
Doença de Alzheimer , Córtex Entorrinal , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Córtex Entorrinal/patologia , Hipocampo/metabolismo , Transtornos da Memória/patologia , Bulbo Olfatório/metabolismo , Ratos
13.
Respir Physiol Neurobiol ; 300: 103870, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35176500

RESUMO

Asthma is a chronic inflammatory disease associated with a high prevalence of psychiatric disorders. There are specific brain networks responsible for emotional processes, including two important networks associated with psychiatric problems: the default mode network (DMN), which is more active in the resting state, and the salience network (SN), which is structurally connected to DMN. Although previous studies suggested that neuro-phenotypes of asthma may be recognizable by the neural activity of brain circuits, an association between the brain's functional alterations and psychiatric impairments induced by asthma remains unknown. We aimed to assess DMN and SN activity and its association with psychiatric indices and clinical parameters in asthmatic patients. Electroencephalography was recorded during the resting state with an awake and eyes-open condition in thirty-eight sex and age-matched subjects (19 atopic asthma patients and 19 healthy participants). Power spectrum and functional connectivity were computed for DMN and SN. We examined psychiatric disorders (including depression, anxiety, and stress) and pulmonary function using the DASS questionnaire and spirometry test, respectively. The results showed that DASS scores were significantly higher in asthmatic patients compared to healthy subjects. Asthmatic patients also demonstrate a significant enhancement in power and functional connectivity in the two networks. Notably, these power enhancements of the networks were correlated with psychiatric problems scores, pulmonary function, asthma duration, and poor asthma control. These results introduce new evidence for the association between altered brain activity, the existence of psychiatric disorders, and asthma-related features, including pulmonary function. Also, we provide new insights into asthma-induced inflammatory response and the importance of developing novel interventions and therapeutic strategies for managing allergic inflammation patients who suffer from concurrent psychiatric disorders.


Assuntos
Asma , Mapeamento Encefálico , Asma/complicações , Asma/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética/métodos , Vias Neurais/diagnóstico por imagem
14.
Neuromodulation ; 25(8): 1351-1363, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35088756

RESUMO

OBJECTIVES: Coma state and loss of consciousness are associated with impaired brain activity, particularly gamma oscillations, that integrate functional connectivity in neural networks, including the default mode network (DMN). Mechanical ventilation (MV) in comatose patients can aggravate brain activity, which has decreased in coma, presumably because of diminished nasal airflow. Nasal airflow, known to drive functional neural oscillations, synchronizing distant brain networks activity, is eliminated by tracheal intubation and MV. Hence, we proposed that rhythmic nasal air puffing in mechanically ventilated comatose patients may promote brain activity and improve network connectivity. MATERIALS AND METHODS: We recorded electroencephalography (EEG) from 15 comatose patients (seven women) admitted to the intensive care unit because of opium poisoning and assessed the activity, complexity, and connectivity of the DMN before and during the nasal air-puff stimulation. Nasal cavity air puffing was done through a nasal cannula controlled by an electrical valve (open duration of 630 ms) with a frequency of 0.2 Hz (ie, 12 puff/min). RESULTS: Our analyses demonstrated that nasal air puffing enhanced the power of gamma oscillations (30-100 Hz) in the DMN. In addition, we found that the coherence and synchrony between DMN regions were increased during nasal air puffing. Recurrence quantification and fractal dimension analyses revealed that EEG global complexity and irregularity, typically seen in wakefulness and conscious state, increased during rhythmic nasal air puffing. CONCLUSIONS: Rhythmic nasal air puffing, as a noninvasive brain stimulation method, opens a new window to modifying the brain connectivity integration in comatose patients. This approach may potentially influence comatose patients' outcomes by increasing brain reactivity and network connectivity.


Assuntos
Coma , Respiração Artificial , Humanos , Feminino , Coma/diagnóstico por imagem , Coma/terapia , Rede de Modo Padrão , Encéfalo/fisiologia , Eletroencefalografia , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Vias Neurais
15.
J Physiol Sci ; 71(1): 21, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193043

RESUMO

Cognitive functions such as working memory require integrated activity among different brain regions. Notably, entorhinal cortex (EC) activity is associated with the successful working memory task. Olfactory bulb (OB) oscillations are known as rhythms that modulate rhythmic activity in widespread brain regions during cognitive tasks. Since the OB is structurally connected to the EC, we hypothesized that OB could modulate EC activity during working memory performance. Herein, we explored OB-EC functional connectivity during spatial working memory performance by simultaneous recording local field potentials when rats performed a Y-maze task. Our results showed that the coherence of delta, theta, and gamma-band oscillations between OB and EC was increased during correct trials compared to wrong trials. Cross-frequency coupling analyses revealed that the modulatory effect of OBs low-frequency phase on EC gamma power and phase was enhanced when animals correctly performed working memory task. The influx of information from OB to EC was also increased at delta and gamma bands within correct trials. These findings indicated that the modulatory influence of OB rhythms on EC oscillations might be necessary for successful working memory performance.


Assuntos
Córtex Entorrinal/fisiologia , Memória de Curto Prazo/fisiologia , Bulbo Olfatório/fisiologia , Memória Espacial/fisiologia , Animais , Ondas Encefálicas/fisiologia , Masculino , Aprendizagem em Labirinto , Ratos , Ratos Wistar
16.
Brain Res ; 1758: 147368, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33582121

RESUMO

Allergic rhinitis (AR) is a chronic inflammatory disease frequently associated with a deficit in learning and memory. Working memory is an important system for decision making and guidance, which depends on interactions between the ventral hippocampus (vHipp) and the prelimbic prefrontal cortex (plPFC). It is still unclear whether AR influences the activity and coupling of these brain areas, which consequently may impair working memory. The current study aimed to examine alterations of the vHipp-plPFC circuit in a rat model of AR. Our results show decreased working memory performance in AR animals, accompanied by a reduction of theta and gamma oscillations in plPFC. Also, AR reduces coherence between vHipp and plPFC in both theta and gamma frequency bands. Cross-frequency coupling analyses confirmed a reduced interaction between hippocampal theta and plPFC gamma oscillations. Granger causality analysis revealed a reduction in the causal effects of vHipp activity on plPFC oscillations and vice versa. A significant correlation was found between working memory performance with disruption of functional connectivity in AR animals. In summary, our data show that in AR, there is a deficit of functional coupling between hippocampal and prefrontal network, and suggest that this mechanism might contribute to working memory impairment in individuals with AR.


Assuntos
Hipocampo/fisiopatologia , Transtornos da Memória/etiologia , Vias Neurais/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Rinite Alérgica/complicações , Animais , Masculino , Transtornos da Memória/fisiopatologia , Memória de Curto Prazo/fisiologia , Ratos , Ratos Wistar , Rinite Alérgica/fisiopatologia
17.
Respir Physiol Neurobiol ; 287: 103627, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33516946

RESUMO

Mechanical ventilation (MV) can result in long-term brain impairments that are resistant to treatment. The mechanisms underlying MV-induced brain function impairment remain unclear. Since nasal airflow modulates brain activity, here we evaluated whether reinstating airflow during MV could influence the memory performance of rats after recovery. Rats were allocated into two study groups: one group received rhythmic air-puff into the nasal cavity during MV and a control group that underwent ventilation without air-puff. During MV, air-puffs induced time-locked event potentials in OB, mPFC and vHPC and significantly increased the oscillatory activity at the air-puff frequency. Furthermore, in mPFC and vHPC, (but not in OB), delta and theta oscillations were more prominent during air-puff application. After recovery, working memory performance was significantly higher in the air-puff group compared to control. Our study thus suggests a promising non-invasive brain stimulation approach to alleviate the neurological complications of prolonged mechanical ventilation.


Assuntos
Ondas Encefálicas/fisiologia , Potenciais Evocados/fisiologia , Hipocampo/fisiologia , Transtornos da Memória/terapia , Memória de Curto Prazo/fisiologia , Bulbo Olfatório/fisiologia , Córtex Pré-Frontal/fisiologia , Ventilação Pulmonar/fisiologia , Respiração Artificial/efeitos adversos , Animais , Comportamento Animal/fisiologia , Modelos Animais de Doenças , Masculino , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Cavidade Nasal , Estimulação Física , Ratos , Ratos Wistar
18.
Artigo em Inglês | MEDLINE | ID: mdl-33037158

RESUMO

BACKGROUND: The biophysical and ultrasonographic properties of the skin change in papulosquamous diseases. AIMS: : To identify biophysical and ultrasonographic properties for the differentiation of five main groups of papulosquamous skin diseases. METHODS: Fifteen biophysical and ultrasonographic parameters were measured by multiprobe adapter system and high-frequency ultrasonography in active lesions and normal control skin in patients with chronic eczema, psoriasis, lichen planus, pityriasis rosea and parapsoriasis/mycosis fungoides. Using histological diagnosis as a gold standard, a decision tree analysis was performed based on the mean percentage changes of these parameters [(lesion-control/control) ×100] for differentiation of the diseases. RESULTS: The accuracy of the decision tree model for differentiation of five diseases was 67% which developed based on changes in stratum corneum hydration, epidermal thickness, skin pH, melanin index, R0 (reciprocal of firmness) and erythema. Among the flowcharts for pairs of diseases, three models for differentiation had high accuracy (> 95%): those of psoriasis from lichen planus, pityriasis rosea, and parapsoriasis/mycosis fungoides. LIMITATIONS: Validation studies on a larger sample size in situations where the diagnosis is unclear are needed to confirm the accuracy and applicability of decision trees. CONCLUSION: Skin biophysical and ultrasonographic properties may help in the differentiation of papulosquamous diseases as simple and non-invasive tools.


Assuntos
Árvores de Decisões , Dermatopatias Papuloescamosas/diagnóstico por imagem , Dermatopatias Papuloescamosas/patologia , Adulto , Biometria , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Dermatopatias Papuloescamosas/fisiopatologia , Fenômenos Fisiológicos da Pele , Ultrassonografia , Adulto Jovem
19.
Iran J Basic Med Sci ; 23(2): 173-177, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32405359

RESUMO

OBJECTIVES: Seizure detection during online recording of electrophysiological parameters is very important in epileptic patients. In the present study, online analysis of field potential recordings was used for detecting spontaneous seizures in epileptic animals. MATERIALS AND METHODS: Epilepsy was induced in rats by pilocarpine injection. During the chronic period of the pilocarpine model, local field potential (LFP) recording was run for at least 24 hr. At the same time, video monitoring of the animals was done to determine the real time of seizure occurrence. Both power and sample entropy of LFP were used for online analysis. RESULTS: Obtained results showed that changes in LFP power are a better index for seizure detection. In addition, when we used one hundred consecutive epochs (each epoch equals 10 ms) of LFP for data analysis, the best detection was achieved. CONCLUSION: It may be suggested that power is a suitable parameter for online analysis of LFP in order to detect the spontaneous seizures correctly.

20.
Sci Rep ; 9(1): 19586, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31863052

RESUMO

Anxiety is prevalent in asthma, and is associated with disease severity and poor quality of life. However, no study to date provides direct experimental evidence for the effect of allergic inflammation on the structure and function of medial prefrontal cortex (mPFC) and amygdala, which are essential regions for modulating anxiety and its behavioral expression. We assessed the impact of ovalbumin (OVA)-induced allergic inflammation on the appearance of anxiety-like behavior, mPFC and amygdala volumes using MRI, and the mPFC-amygdala circuit activity in sensitized rats. Our findings exhibited that the OVA challenge in sensitized rats induced anxiety-like behavior, and led to more activated microglia and astrocytes in the mPFC and amygdala. We also found a negative correlation between anxiety-like behavior and amygdala volume. Moreover, OVA challenge in sensitized rats was associated with increases in mPFC and amygdala activity, elevation of amygdala delta-gamma coupling, and the enhancement of functional connectivity within mPFC-amygdala circuit - accompanied by an inverted direction of information transferred from the amygdala to the mPFC. We indicated that disrupting the dynamic interactions of the mPFC-amygdala circuit may contribute to the induction of anxiety-related behaviors with asthma. These findings could provide new insight to clarify the underlying mechanisms of allergic inflammation-induced psychiatric disorders related to asthma.


Assuntos
Alérgenos/química , Tonsila do Cerebelo/fisiopatologia , Ansiedade/fisiopatologia , Asma/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Animais , Ansiedade/induzido quimicamente , Asma/induzido quimicamente , Asma/psicologia , Comportamento Animal , Modelos Animais de Doenças , Inflamação , Pulmão/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Aprendizagem em Labirinto , Ovalbumina/química , Ratos , Ratos Wistar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA