RESUMEN
BACKGROUND: Previous studies have reported that the sense of "self" is associated with specific brain regions and neural network activities. In addition, the mirror system, which functions when executing or observing an action, might contribute to differentiating the self from others and form the basis of the sense of self as a fundamental physical representation. This study investigated whether differences in mu suppression, an indicator of mirror system activity, reflect cognitions related to self-other discrimination. METHODS: The participants were 30 of healthy college students. The participants observed short video clips of hand movements performed by themselves or actors from two perspectives (i.e., first-person and third-person). The electroencephalogram (EEG) mu rhythm (8-13 Hz) was measured during video observation as an index of mirror neuron system activity. EEG activity related to self-detection was analyzed using participants' hand movements as self-relevant stimuli. RESULTS: The results showed that mu suppression in the 8-13-Hz range exhibited perspective-dependent responses to self/other stimuli. There was a significant self-oriented mu suppression response in the first-person perspective. However, the study found no significant response orientation in the third-person perspective. The results suggest that mirror system activity may involve self-other discrimination differently depending on the perspective. CONCLUSIONS: In summary, this study examined the mirror system's activity for self and others using the EEG's mu suppression. As a result, it was suggested that differences in self and others or perspectives may influence mu suppression.
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Electroencefalografía , Mano , Movimiento , Humanos , Femenino , Masculino , Mano/fisiología , Adulto Joven , Movimiento/fisiología , Adulto , Neuronas Espejo/fisiología , Ondas Encefálicas/fisiologíaRESUMEN
Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor symptoms like tremors and bradykinesia. PD's pathology involves the aggregation of α-synuclein and loss of dopaminergic neurons, leading to altered neural oscillations in the cortico-basal ganglia-thalamic network. Despite extensive research, the relationship between the motor symptoms of PD and transient changes in brain oscillations before and after motor tasks in different brain regions remain unclear. This study aimed to investigate neural oscillations in both healthy and PD model mice using local field potential (LFP) recordings from multiple brain regions during rest and locomotion. The histological evaluation confirmed the significant dopaminergic neuron loss in the injection side in 6-OHDA lesioned mice. Behavioral tests showed motor deficits in these mice, including impaired coordination and increased forelimb asymmetry. The LFP analysis revealed increased delta, theta, alpha, beta, and gamma band activity in 6-OHDA lesioned mice during movement, with significant increases in multiple brain regions, including the primary motor cortex (M1), caudate-putamen (CPu), subthalamic nucleus (STN), substantia nigra pars compacta (SNc), and pedunculopontine nucleus (PPN). Taken together, these results show that the motor symptoms of PD are accompanied by significant transient increases in brain oscillations, especially in the gamma band. This study provides potential biomarkers for early diagnosis and therapeutic evaluation by elucidating the relationship between specific neural oscillations and motor deficits in PD.
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Modelos Animales de Enfermedad , Enfermedad de Parkinson , Animales , Ratones , Enfermedad de Parkinson/fisiopatología , Masculino , Oxidopamina , Ratones Endogámicos C57BL , Corteza Motora/fisiopatología , Corteza Motora/metabolismo , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Encéfalo/fisiopatología , Encéfalo/patología , Encéfalo/metabolismo , Ondas Encefálicas , Actividad MotoraRESUMEN
Cell replacement therapies using medial ganglionic eminence (MGE)-derived GABAergic precursors reduce seizures by restoring inhibition in animal models of epilepsy. However, how MGE-derived cells affect abnormal neuronal networks and consequently brain oscillations to reduce ictogenesis is still under investigation. We performed quantitative analysis of pre-ictal local field potentials (LFP) of cortical and hippocampal CA1 areas recorded in vivo in the pilocarpine rat model of epilepsy, with or without intrahippocampal MGE-precursor grafts (PILO and PILO+MGE groups, respectively). The PILO+MGE animals had a significant reduction in the number of seizures. The quantitative analysis of pre-ictal LFP showed decreased power of cortical and hippocampal delta, theta and beta oscillations from the 5 min. interictal baseline to the 20 s. pre-ictal period in both groups. However, PILO+MGE animals had higher power of slow and fast oscillations in the cortex and lower power of slow and fast oscillations in the hippocampus compared to the PILO group. Additionally, PILO+MGE animals exhibited decreased cortico-hippocampal synchrony for theta and gamma oscillations at seizure onset and lower hippocampal CA1 synchrony between delta and theta with slow gamma oscillations compared to PILO animals. These findings suggest that MGE-derived cell integration into the abnormally rewired network may help control ictogenesis.
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Corteza Cerebral , Modelos Animales de Enfermedad , Epilepsia , Hipocampo , Pilocarpina , Animales , Pilocarpina/toxicidad , Hipocampo/fisiopatología , Masculino , Corteza Cerebral/fisiopatología , Epilepsia/inducido químicamente , Epilepsia/fisiopatología , Ratas , Ondas Encefálicas/fisiología , Ratas Wistar , Electroencefalografía , Eminencia GanglionarRESUMEN
OBJECTIVE: Schizophrenia (SCZ) is a globally prevalent, severe chronic mental disorder, with cognitive dysfunction being one of its core symptoms. Notably, overweight is exceedingly common among individuals with SCZ, and overweight can also impact cognitive function. Therefore, the relationship between overweight and cognition in SCZ is a clinical issue that is in need of research attention. METHODS: This study enrolled 77 patients with SCZ, including 36 overweight and 41 non-overweight patients. The Positive and Negative Syndrome Scale (PANSS) was used to assess symptom severity, while cognitive functions were evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Electroencephalography (EEG) testing was performed, with power spectral analysis conducted across various frequency bands (δ, θ, α, ß, low γ, and high γ). RESULTS: Compared to non-overweight SCZ patients, those overweight exhibited significantly lower RBANS total and index scores in immediate memory, visuospatial/constructional abilities, and delayed memory. EEG spectral analysis revealed that overweight SCZ patients demonstrated significantly lower oscillation power ratios in the ß, low γ, and high γ frequency bands compared to their non-overweight counterparts. Correlation analyses indicated a significant positive relationship between ß wave activity and RBANS total scores among overweight SCZ patients, suggesting that reduced ß power correlates with more severe cognitive dysfunction. CONCLUSION: Our findings indicate that overweight SCZ patients experience more severe cognitive impairments in a resting state than those who are not overweight, with significant differences in EEG spectrum observed in the ß and γ frequency bands. Additionally, our study establishes a correlation between various EEG spectrum dimensions and cognition. This research highlights the effects of overweight on cognition in individuals with SCZ. Additionally, employing EEG technology to study cognitive function in overweight SCZ patients can offer valuable electrophysiological insights.
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Disfunción Cognitiva , Electroencefalografía , Sobrepeso , Esquizofrenia , Humanos , Masculino , Femenino , Esquizofrenia/fisiopatología , Esquizofrenia/complicaciones , Adulto , Sobrepeso/fisiopatología , Sobrepeso/complicaciones , Sobrepeso/epidemiología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Persona de Mediana Edad , Ondas Encefálicas/fisiología , Pruebas Neuropsicológicas , Adulto JovenRESUMEN
BACKGROUND: "Metacontrol" describes the ability to maintain an optimal balance between cognitive control styles that are either more persistent or more flexible. Recent studies have shown a link between metacontrol and aperiodic EEG patterns. The present study aimed to gain more insight into the neurobiological underpinnings of metacontrol by using methylphenidate (MPH), a compound known to increase postsynaptic catecholamine levels and modulate cortical noise. METHODS: In a double-blind, randomized, placebo-controlled study design, we investigated the effect of MPH (0.5 mg/kg) on aperiodic EEG activity during a flanker task in a sample of n = 25 neurotypical adults. To quantify cortical noise, we employed the fitting oscillations and one over f algorithm. RESULTS: Compared with placebo, MPH increased the aperiodic exponent, suggesting that it reduces cortical noise in 2 ways. First, it did so in a state-like fashion, as the main effect of the drug was visible and significant in both pre-trial and within-trial periods. Second, the electrode-specific analyses showed that the drug also affects specific processes by dampening the downregulation of noise in conditions requiring more control. CONCLUSIONS: Our findings suggest that the aperiodic exponent provides a neural marker of metacontrol states and changes therein. Further, we propose that the effectiveness of medications targeting catecholaminergic signaling can be evaluated by studying changes of cortical noise, fostering the idea of using the quantification of cortical noise as an indicator in pharmacological treatment.
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Electroencefalografía , Metilfenidato , Humanos , Método Doble Ciego , Metilfenidato/farmacología , Masculino , Adulto , Femenino , Electroencefalografía/efectos de los fármacos , Adulto Joven , Estimulantes del Sistema Nervioso Central/farmacología , Catecolaminas/metabolismo , Ondas Encefálicas/efectos de los fármacosRESUMEN
Recently, there has been a resurgence in experimental and conceptual efforts to understand how brain rhythms can serve to organize visual information. Oscillations can provide temporal structure for neuronal processing and form a basis for integrating information across brain areas. Here, we use a bistable paradigm and a data-driven approach to test the hypothesis that oscillatory modulations associate with the integration or segregation of visual elements. Spectral signatures of perception of bound and unbound configurations of visual moving stimuli were studied using magnetoencephalography (MEG) in ambiguous and unambiguous conditions. Using a 2 × 2 design, we were able to isolate correlates from visual integration, either perceptual or stimulus-driven, from attentional and ambiguity-related activity. Two frequency bands were found to be modulated by visual integration: an alpha/beta frequency and a higher frequency gamma-band. Alpha/beta power was increased in several early visual cortical and dorsal visual areas during visual integration, while gamma-band power was surprisingly increased in the extrastriate visual cortex during segregation. This points to an integrative role for alpha/beta activity, likely from top-down signals maintaining a single visual representation. On the other hand, when more representations have to be processed in parallel gamma-band activity is increased, which is at odds with the notion that gamma oscillations are related to perceptual coherence. These modulations were confirmed in intracranial EEG recordings and partially originate from distinct brain areas. Our MEG and stereo-EEG data confirms predictions of binding mechanisms depending on low-frequency activity for long-range integration and for organizing visual processing while refuting a straightforward correlation between gamma-activity and perceptual binding. PRACTITIONER POINTS: Distinct neurophysiological signals underlie competing bistable percepts. Increased alpha/beta activity correlate with visual integration while gamma correlates with segmentation. Ambiguous percepts drive alpha/beta activity in the posterior cingulate cortex.
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Magnetoencefalografía , Humanos , Masculino , Adulto , Femenino , Adulto Joven , Ondas Encefálicas/fisiología , Corteza Visual/fisiología , Percepción de Movimiento/fisiología , Percepción Visual/fisiología , Ritmo Gamma/fisiología , Atención/fisiología , Mapeo EncefálicoRESUMEN
Generalized epilepsy (GE) encompasses a heterogeneous group of hyperexcitability disorders that clinically manifest as seizures. At the whole-brain level, distinct seizure patterns as well as interictal epileptic discharges (IEDs) reflect key signatures of hyperexcitability in magneto- and electroencephalographic (M/EEG) recordings. Moreover, it had been suggested that aperiodic activity, specifically the slope of the 1/ƒx decay function of the power spectrum, might index neural excitability. However, it remained unclear if hyperexcitability as encountered at the cellular level directly translates to putative large-scale excitability signatures, amenable to M/EEG. In order to test whether the power spectrum is altered in hyperexcitable states, we recorded resting-state MEG from male and female GE patients (nâ =â 51; 29 females; 28.82 ± 12.18â years; mean ± SD) and age-matched healthy controls (n = 49; 22 females; 32.10 ± 12.09â years). We parametrized the power spectra using FOOOF ("fitting oscillations and one over f") to separate oscillatory from aperiodic activity to directly test whether aperiodic activity is systematically altered in GE patients. We further identified IEDs to quantify the temporal dynamics of aperiodic activity around overt epileptic activity. The results demonstrate that aperiodic activity indexes hyperexcitability in GE at the whole-brain level, especially during epochs when no IEDs were present (pâ =â 0.0130; d = 0.52). Upon IEDs, large-scale circuits transiently shifted to a less excitable network state (p = 0.001; d = 0.68). In sum, these results uncover that MEG background activity might index hyperexcitability based on the current brain state and does not rely on the presence of epileptic waveforms.
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Electroencefalografía , Epilepsia Generalizada , Magnetoencefalografía , Humanos , Femenino , Masculino , Adulto , Epilepsia Generalizada/fisiopatología , Adulto Joven , Adolescente , Encéfalo/fisiopatología , Persona de Mediana Edad , Ondas Encefálicas/fisiologíaRESUMEN
Recent studies using resting-state functional magnetic resonance imaging have shown that loneliness is associated with altered blood oxygenation in several brain regions. However, the relationship between loneliness and changes in neuronal rhythm activity in the brain remains unclear. To evaluate brain rhythm, we conducted an exploratory resting-state electroencephalogram (EEG) study of loneliness. We recorded resting-state EEG signals from 139 participants (94 women; mean age = 19.96 years) and analyzed power spectrum density (PSD) and functional connectivity (FC) in both the electrode and source spaces. The PSD analysis revealed significant correlations between loneliness scores and decreased beta-band powers, which may indicate negative emotion, attention, reward, and/or sensorimotor processing. The FC analysis revealed a trend of alpha-band FC associated with individuals' loneliness scores. These findings provide new insights into the neural basis of loneliness, which will facilitate the development of neurobiologically informed interventions for loneliness.
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Encéfalo , Electroencefalografía , Soledad , Descanso , Humanos , Femenino , Soledad/psicología , Masculino , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Adulto Joven , Electroencefalografía/métodos , Descanso/fisiología , Adulto , Adolescente , Ondas Encefálicas/fisiología , Mapeo EncefálicoRESUMEN
Human mobility requires neurocognitive inputs to safely navigate the environment. Previous research has examined neural processes that underly walking using mobile neuroimaging technologies, yet few studies have incorporated true real-world methods without a specific task imposed on participants (e.g., dual-task, motor demands). The present study included 40 young adults (M = 22.60, SD = 2.63, 24 female) and utilized mobile electroencephalography (EEG) to examine and compare theta, alpha, and beta frequency band power (µV2) during sitting and walking in laboratory and real-world environments. EEG data was recorded using the Muse S brain sensing headband, a portable system equipped with four electrodes (two frontal, two temporal) and one reference sensor. Qualitative data detailing the thoughts of each participant were collected after each condition. For the quantitative data, a 2 × 2 repeated measures ANOVA with within subject factors of environment and mobility was conducted with full participant datasets (n = 17, M = 22.59, SD = 2.97, 10 female). Thematic analysis was performed on the qualitative data (n = 40). Our findings support that mobility and environment may modulate neural activity, as we observed increased brain activation for walking compared to sitting, and for real-world walking compared to laboratory walking. We identified five qualitative themes across the four conditions 1) physical sensations and bodily awareness, 2) responsibilities and planning, 3) environmental awareness, 4) mobility, and 5) spotlight effect. Our study highlights the importance and potential for real-world methods to supplement standard research practices to increase the ecological validity of studies conducted in the fields of neuroscience and kinesiology.
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Electroencefalografía , Caminata , Humanos , Femenino , Masculino , Adulto Joven , Adulto , Caminata/fisiología , Corteza Cerebral/fisiología , Ondas Encefálicas/fisiología , Sedestación , AmbienteRESUMEN
BACKGROUND: Ictal stereo-encephalography (sEEG) biomarkers for seizure onset zone (SOZ) localization can be classified depending on whether they target abnormalities in signal power or functional connectivity between signals, and they may depend on the frequency band and time window at which they are estimated. NEW METHOD: This work aimed to compare and optimize the performance of a power and a connectivity-based biomarker to identify SOZ contacts from ictal sEEG recordings. To do so, we used a previously introduced power-based measure, the normalized mean activation (nMA), which quantifies the ictal average power activation. Similarly, we defined the normalized mean strength (nMS), to quantify the ictal mean functional connectivity of every contact with the rest. The optimal frequency bands and time windows were selected based on optimizing AUC and F2-score. RESULTS: The analysis was performed on a dataset of 67 seizures from 10 patients with pharmacoresistant temporal lobe epilepsy. Our results suggest that the power-based biomarker generally performs better for the detection of SOZ than the connectivity-based one. However, an equivalent performance level can be achieved when both biomarkers are independently optimized. Optimal performance was achieved in the beta and lower-gamma range for the power biomarker and in the lower- and higher-gamma range for connectivity, both using a 20 or 30 s period after seizure onset. CONCLUSIONS: The results of this study highlight the importance of this optimization step over frequency and time windows when comparing different SOZ discrimination biomarkers. This information should be considered when training SOZ classifiers on retrospective patients' data for clinical applications.
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Epilepsia del Lóbulo Temporal , Humanos , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/diagnóstico , Adulto , Masculino , Femenino , Electroencefalografía/métodos , Convulsiones/fisiopatología , Convulsiones/diagnóstico , Procesamiento de Señales Asistido por Computador , Persona de Mediana Edad , Adulto Joven , Biomarcadores , Técnicas Estereotáxicas , Epilepsia Refractaria/fisiopatología , Epilepsia Refractaria/diagnóstico , Encéfalo/fisiopatología , Ondas Encefálicas/fisiologíaRESUMEN
Down syndrome (DS) is the most common cause of intellectual disability, yet little is known about the neurobiological pathways leading to cognitive impairments. Electroencephalographic (EEG) measures are commonly used to study neurodevelopmental disorders, but few studies have focused on young children with DS. Here we assess resting state EEG data collected from toddlers/preschoolers with DS (n = 29, age 13-48 months old) and compare their aperiodic and periodic EEG features with both age-matched (n = 29) and developmental-matched (n = 58) comparison groups. DS participants exhibited significantly reduced aperiodic slope, increased periodic theta power, and decreased alpha peak amplitude. A majority of DS participants displayed a prominent peak in the theta range, whereas a theta peak was not present in age-matched participants. Overall, similar findings were also observed when comparing DS and developmental-matched groups, suggesting that EEG differences are not explained by delayed cognitive ability.
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Síndrome de Down , Electroencefalografía , Humanos , Síndrome de Down/fisiopatología , Masculino , Femenino , Electroencefalografía/métodos , Lactante , Preescolar , Encéfalo/fisiopatología , Ritmo Teta/fisiología , Ondas Encefálicas/fisiologíaRESUMEN
BACKGROUND: The analysis of EEG demands expertise and keen observation to distinguish epileptiform discharges from benign epileptiform variants (BEVs), a frequent source of erroneous interpretation. The prevalence of BEVs varies based on geographical, racial, and ethnic characteristics. However, most data on BEVs originates from Western populations, and additional studies on different cohorts would enrich the existing literature. METHODS: We reviewed EEGs from our institutional database to study the prevalence of benign epileptiform variants and analyzed their frequency, topography, and other characteristics. Additionally, we investigated the co-existence of epileptiform discharges with BEVs. RESULTS: We identified 296 patients with BEVs after reviewing 3000 EEGs (9.9%). The most common BEV was small sharp spikes (SSS), observed in 114 patients (3.8%). Wicket waves, 6 Hz spike and slow wave, 14 and 6 Hz positive bursts, and Rhythmic Temporal Theta of Drowsiness (RTTD) were identified in 67 (2.2%), 40 (1.3%), 39 (1.3%), and 35 (1.16%) patients, respectively and one patient with Subclinical Rhythmic EEG Discharges in Adults (SREDA). Additionally, we observed the co-existence of epileptiform discharges with BEVs, most commonly with SSS (27.8%). CONCLUSIONS: The present study is a large study with 3000 EEGs to describe the BEV characteristics. BEVs were seen in 9.9% of patients, BSSS being the most common. There were minor differences in frequency, gender or age distribution compared to existing literature. We demonstrated the co-existence of epileptiform discharges. Morphological characteristics remain the cornerstone in recognising BEVs. EEG readers need to be aware of features of BEVs to avoid wrongly interpretation.
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Electroencefalografía , Epilepsia , Humanos , Electroencefalografía/métodos , Femenino , Masculino , Adulto , Adulto Joven , Adolescente , Niño , Epilepsia/fisiopatología , Epilepsia/diagnóstico , Persona de Mediana Edad , Preescolar , Lactante , Estudios Retrospectivos , Anciano , Encéfalo/fisiopatología , Ondas Encefálicas/fisiologíaRESUMEN
Brain oscillations are crucial for perception, memory, and behavior. Parvalbumin-expressing (PV) interneurons are critical for these oscillations, but their population dynamics remain unclear. Using voltage imaging, we simultaneously recorded membrane potentials in up to 26 PV interneurons in vivo during hippocampal ripple oscillations in mice. We found that PV cells generate ripple-frequency rhythms by forming highly dynamic cell assemblies. These assemblies exhibit rapid and significant changes from cycle to cycle, varying greatly in both size and membership. Importantly, this variability is not just random spiking failures of individual neurons. Rather, the activities of other PV cells contain significant information about whether a PV cell spikes or not in a given cycle. This coordination persists without network oscillations, and it exists in subthreshold potentials even when the cells are not spiking. Dynamic assemblies of interneurons may provide a new mechanism to modulate postsynaptic dynamics and impact cognitive functions flexibly and rapidly.
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Interneuronas , Parvalbúminas , Animales , Parvalbúminas/metabolismo , Interneuronas/fisiología , Ratones , Hipocampo/fisiología , Hipocampo/citología , Potenciales de Acción/fisiología , Encéfalo/fisiología , Encéfalo/citología , Ratones Transgénicos , Ondas Encefálicas/fisiología , MasculinoRESUMEN
Cognitive impairments are common in Parkinson's disease (PD). We have linked this deficit to attenuated midfrontal 1-8-Hz activity that fails to engage cortical cognitive networks. We discuss the consequences of these impairments and how they might be leveraged for PD-specific neurophysiological markers and for novel brain stimulation paradigms.
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Disfunción Cognitiva , Enfermedad de Parkinson , Enfermedad de Parkinson/fisiopatología , Humanos , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/etiología , Ondas Encefálicas/fisiología , Cognición/fisiología , Encéfalo/fisiopatologíaRESUMEN
PURPOSE: The study aims to evaluate the effectiveness of brainwave entrainment on pre-operative fear and anxiety in pediatric dental patients. METHODS: The study protocol received approval from the Institutional Ethical Committee under reference number 3010/IEC/2021. Pediatric patients (252) aged from 7 to 12 years, who reported to the dental department were randomized pre-operatively and presented either with brainwave entrainment (experimental), delivered using a "David delight plus device" or a standard behavior management protocol (control). Baseline and post-assessment of anxiety and fear levels were done using the Visual Facial Anxiety Scale and Frankl's behavior rating scale with Wright's modification. Vitals such as blood pressure and pulse rate were also measured. RESULTS: The study sample (n = 252) comprised 118 females and 134 males. The non-significant differences for values of (VFAS1, FRS1, HR1, and BP1) indicated similar baseline characteristics. In the brainwave entrainment group, the p values of the Mann-Whitney U test and Wilcoxon Signed Ranks test (p < 0.01) between the two-timepoints indicated a statistical difference for the values of (VFAS1, FBRS1, HR1, BP1) and (VFAS2, FBRS2, HR2, BP2). CONCLUSIONS: Brainwave entrainment effectively reduces pre-operative fear and anxiety in pediatric dental patients. Therefore, they can be a non-pharmacological and non-invasive behavior management aid. TRIAL REGISTRATION: Clinical Trial Registry of India database CTRI/2023/03/051066.
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Ansiedad al Tratamiento Odontológico , Humanos , Niño , Masculino , Femenino , Ansiedad al Tratamiento Odontológico/prevención & control , Ondas Encefálicas/fisiología , Atención Dental para Niños/métodos , Terapia Conductista/métodos , Miedo/psicologíaRESUMEN
Abnormal patterns of brain connectivity characterize epilepsy. However, little is known about these patterns during the stages preceding a seizure induced by pentylenetetrazol (PTZ). To investigate brain connectivity in male Wistar rats during the preictal phase of PTZ-induced seizures (60 mg/kg), we recorded local field potentials in the primary motor (M1) cortex, the ventral anterior (VA) nucleus of the thalamus, the hippocampal CA1 area, and the dentate gyrus (DG) during the baseline period and after PTZ administration. While there were no changes in power density between the baseline and preictal periods, we observed an increase in directional functional connectivity in theta from the hippocampal formation to M1 and VA, as well as in middle gamma from DG to CA1 and from CA1 to M1, and also in slow gamma from M1 to CA1. These findings are supported by increased phase coherence between DG-M1 in theta and CA1-M1 in middle gamma, as well as enhanced phase-amplitude coupling of delta-middle gamma in M1 and delta-fast gamma in CA1. Interestingly, we also noted a slight decrease in phase synchrony between CA1 and VA in slow gamma. Together, these results demonstrate increased functional connectivity between brain regions during the PTZ-induced preictal period, with this increase being particularly driven by the hippocampal formation.
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Encéfalo , Pentilenotetrazol , Ratas Wistar , Convulsiones , Animales , Pentilenotetrazol/farmacología , Masculino , Convulsiones/inducido químicamente , Convulsiones/fisiopatología , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Ratas , Vías Nerviosas/fisiopatología , Vías Nerviosas/efectos de los fármacos , Modelos Animales de Enfermedad , Electroencefalografía/métodos , Región CA1 Hipocampal/efectos de los fármacos , Región CA1 Hipocampal/fisiopatología , Convulsivantes/toxicidad , Convulsivantes/farmacología , Ondas Encefálicas/efectos de los fármacos , Ondas Encefálicas/fisiología , Corteza Motora/efectos de los fármacos , Corteza Motora/fisiopatologíaRESUMEN
OBJECTIVE: Coupling of sleep spindles with cortical slow waves and hippocampus sharp-waves ripples is crucial for sleep-related memory consolidation. Recent literature evidenced that nasal respiration modulates neural activity in large-scale brain networks. In rodents, this respiratory drive strongly varies according to vigilance states. Whether sleep oscillations are also respiration-modulated in humans remains open. In this work, we investigated the influence of breathing on sleep spindles during non-rapid-eye-movement sleep in humans. METHODS: Full night polysomnography of twenty healthy participants were analysed. Spindles and slow waves were automatically detected during N2 and N3 stages. Spindle-related sigma power as well as spindle and slow wave events were analysed according to the respiratory phase. RESULTS: We found a significant coupling between both slow and fast spindles and the respiration cycle, with enhanced sigma activity and occurrence probability of spindles during the middle part of the expiration phase. A different coupling was observed for slow waves negative peaks which were rather distributed around the two respiration phase transitions. CONCLUSION: Our findings suggest that breathing cycle influences the dynamics of brain activity during non-rapid-eye-movement sleep. SIGNIFICANCE: This coupling may enable sleep spindles to synchronize with other sleep oscillations and facilitate information transfer between distributed brain networks.
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Electroencefalografía , Respiración , Fases del Sueño , Humanos , Masculino , Femenino , Adulto , Fases del Sueño/fisiología , Polisomnografía , Adulto Joven , Sueño/fisiología , Ondas Encefálicas/fisiologíaRESUMEN
Auditory beats stimulation (ABS) has received increased attention for its potential to modulate neural oscillations through a phenomenon described as brain entrainment (i.e synchronization of brain's electrocortical activity to external stimuli at a specific frequency). Recently, a new form of ABS has emerged, inspired by isochronic tones stimulation (ITd). This study investigated neural oscillatory responses induced by ITd in comparison with formerly well-established ABS protocols, such as gamma-binaural beats (BB) and white noise (WN). We recorded the electroencephalographic brain activity in 28 participants during 4 min of BB, ITd, and WN presentation. Data demonstrated that while both BB and WN enhanced oscillatory power on the EEG gamma band, consistently with the expected brain entrainment effect, ITd yielded greater changes in EEG power (p < 0.001). This was confirmed by time-based analysis, which showed a progressive increase in normalized EEG power within the ITd window compared to BB (p < 0.05). Findings also revealed that ITd elicited acute changes in the alpha band of EEG oscillations, through a progressive decrease in power over time, which was distinctly different from the pattern observed while listening BB and WN. Such dual alpha-gamma effects underline the promising and unique potential of ITd to modulate neural oscillations which selectively differ from BB and WN. This study contributes to the evolution of ABS research, highlighting the promise of ITd for cognitive enhancement and clinical applications.
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Estimulación Acústica , Percepción Auditiva , Electroencefalografía , Humanos , Masculino , Femenino , Estimulación Acústica/métodos , Electroencefalografía/métodos , Adulto Joven , Adulto , Percepción Auditiva/fisiología , Encéfalo/fisiología , Ondas Encefálicas/fisiología , Potenciales Evocados Auditivos/fisiología , Ritmo Gamma/fisiologíaRESUMEN
Introduction: High velocity thrust manipulation is commonly used when managing joint dysfunctions. Often, these thrust maneuvers will elicit an audible pop. It has been unclear what conclusively causes this audible sound and its clinical meaningfulness. This study sought to identify the effect of the audible pop on brainwave activity directly following a prone T7 thrust manipulation in asymptomatic/healthy subjects. Methods: This was a quasi-experimental repeated measure study design in which 57 subjects completed the study protocol. Brain wave activity was measured with the Emotiv EPOC+, which collects data with a frequency of 128 HZ and has 14 electrodes. Testing was performed in a controlled environment with minimal electrical interference (as measured with a Gauss meter), temperature variance, lighting variance, sound pollution, and other variable changes that could have influenced or interfered with pure EEG data acquisition. After accommodation each subject underwent a prone T7 posterior-anterior thrust manipulation. Immediately after the thrust manipulation the brainwave activity was measured for 10 seconds. Results: The non-audible group (N = 20) consisted of 55% males, and the audible group (N = 37) consisted of 43% males. The non-audible group EEG data revealed a significant change in brain wave activity under some of the electrodes in the frontal, parietal, and the occipital lobes. In the audible group, there was a significant change in brain wave activity under all electrodes in the frontal lobes, the parietal lobe, and the occipital lobes but not the temporal lobes. Conclusion: The audible sounds caused by a thoracic high velocity thrust manipulation did not affect the activity in the audible centers in the temporal brain region. The results support the hypothesis that thrust manipulation with or without audible sound results in a generalized relaxation immediately following the manipulation. The absence of a significant difference in brainwave activity in the frontal lobe in this study might indicate that the audible pop does not produce a "placebo" mechanism.
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Manipulación Espinal , Humanos , Masculino , Femenino , Adulto , Manipulación Espinal/métodos , Ondas Encefálicas/fisiología , Electroencefalografía/métodos , Adulto Joven , SonidoRESUMEN
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