Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 153
Filter
Add more filters

Publication year range
1.
J Anat ; 241(1): 20-32, 2022 07.
Article in English | MEDLINE | ID: mdl-35178703

ABSTRACT

Von Economo neurons (VENs) have been mentioned in the medical literature since the second half of the 19th century; however, it was not until the second decade of the 20th century that their cytomorphology was described in detail. To date, VENs have been found in limbic sectors of the frontal, temporal and insular lobes. In humans, their density seems to decrease in the caudo-rostral and ventro-dorsal direction; that is, from the anterior regions of the cingulate and insular cortices towards the frontal pole and the superior frontal gyrus. Several studies have provided similar descriptions of the shape of the VEN soma, but the size of the soma varies from one cortical region to another. There is consensus among different authors about the selective vulnerability of VENs in certain pathologies, in which a deterioration of the capacities involved in social behaviour is observed. In this review, we propose that the restriction of VENs towards the sectors linked to limbic information processing in Homo sapiens gives them a possible functional role in relation to the structures in which they are located. However, given the divergence in characteristics such as location, density, size and biochemical profile among VENs of different cortical sectors, the activities in which they participate could allow them to partake in a wide spectrum of neurological functions, including autonomic responses and executive functions.


Subject(s)
Hominidae , Neurons , Animals , Cerebral Cortex , Frontal Lobe , Gyrus Cinguli , Hominidae/anatomy & histology , Humans , Limbic Lobe
2.
Ecotoxicol Environ Saf ; 208: 111495, 2021 Jan 15.
Article in English | MEDLINE | ID: mdl-33099139

ABSTRACT

Different techniques have been developed for the remediation of Cu contaminated soils, being the phytoremediation a sustainable and environmentally friendly strategy, but its use in mine tailings is scarce. Arbuscular mycorrhizal fungi (AMF) can decrease the Cu concentration in plants by favouring the stabilization of this metal through different mechanisms such as the production of glomalin, immobilization in the fungal wall of hyphae and spores, and the storage of Cu in vacuoles. Additionally, the use of organic amendments promotes the beneficial effects produced by AMF and improves plant growth. Based on the above, the aim of this study was to determine the effect of AMF inoculation and compost application at different doses on the growth of Oenothera picensis in a Cu mine tailing. One group of plants were inoculated with Claroideoglomus claroideum (CC) and other was non-inoculated (NM). Both CC and NM were grown for two month under greenhouse conditions in pots with the Cu mine tailing, which also had increasing compost doses (0%, 2.5%, 5%, and 10%). Results showed greater biomass production of O. picensis by CC up to 2-fold compared with NM. This effect was improved by the compost addition, especially at doses of 5% and 10%. Therefore, the increase of mycorrhizal and nutritional parameters in O. picensis, and the decreasing of Cu availability in the mine tailing, promoted the production of photosynthetic pigments together with the plant growth, which is of importance to accomplish phytoremediation programs in Cu mine tailings.


Subject(s)
Composting/methods , Copper/metabolism , Fungi/physiology , Oenothera/microbiology , Soil Pollutants/metabolism , Biodegradation, Environmental , Biomass , Copper/analysis , Fungi/metabolism , Mining , Mycorrhizae/metabolism , Mycorrhizae/physiology , Oenothera/growth & development , Oenothera/metabolism , Soil/chemistry , Soil Pollutants/analysis
3.
Appl Psychophysiol Biofeedback ; 46(2): 161-173, 2021 06.
Article in English | MEDLINE | ID: mdl-33877491

ABSTRACT

Research suggest that in autism spectrum disorder (ASD) a disturbance in the coordinated interactions of neurons within local networks gives rise to abnormal patterns of brainwave activity in the gamma bandwidth. Low frequency transcranial magnetic stimulation (TMS) over the dorsolateral prefrontal cortex (DLPFC) has been proven to normalize gamma oscillation abnormalities, executive functions, and repetitive behaviors in high functioning ASD individuals. In this study, gamma frequency oscillations in response to a visual classification task (Kanizsa figures) were analyzed and compared in 19 ASD (ADI-R diagnosed, 14.2 ± 3.61 years old, 5 girls) and 19 (14.8 ± 3.67 years old, 5 girls) age/gender matched neurotypical individuals. The ASD group was treated with low frequency TMS (1.0 Hz, 90% motor threshold, 18 weekly sessions) targeting the DLPFC. In autistic subjects, as compared to neurotypicals, significant differences in event-related gamma oscillations were evident in amplitude (higher) pre-TMS. In addition, recordings after TMS treatment in our autistic subjects revealed a significant reduction in the time period to reach peak amplitude and an increase in the decay phase (settling time). The use of a novel metric for gamma oscillations. i.e., envelope analysis, and measurements of its ringing decay allowed us to characterize the impedance of the originating neuronal circuit. The ringing decay or dampening of gamma oscillations is dependent on the inhibitory tone generated by networks of interneurons. The results suggest that the ringing decay of gamma oscillations may provide a biomarker reflective of the excitatory/inhibitory balance of the cortex and a putative outcome measure for interventions in autism.


Subject(s)
Autism Spectrum Disorder , Transcranial Magnetic Stimulation , Adolescent , Autism Spectrum Disorder/therapy , Child , Executive Function , Female , Humans , Physical Therapy Modalities , Prefrontal Cortex
4.
Neuropathol Appl Neurobiol ; 42(2): 115-34, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25630827

ABSTRACT

The cerebral cortex undergoes protracted maturation during human development and exemplifies how biology and environment are inextricably intertwined in the construction of complex neural circuits. Autism spectrum disorders are characterized by a number of pathological changes arising from this developmental process. These include: (i) alterations to columnar structure that have significant implications for the organization of cortical circuits and connectivity; (ii) alterations to synaptic spines on individual cortical units that may underlie specific types of connectional changes; and (iii) alterations within the cortical subplate, a region that plays a role in proper cortical development and in regulating interregional communication in the mature brain. Although the cerebral cortex is not the only structure affected in the disorder, it is a fundamental contributor to the behaviours that characterize autism. These alterations to cortical circuitry likely underlie the behavioural phenotype in autism and contribute to the unique pattern of deficits and strengths that characterize cognitive functioning. Recent findings within the cortical subplate may indicate that alterations to cortical construction begin prenatally, before activity-dependent connections are established, and are in need of further study. A better understanding of cortical development in autism spectrum disorders will draw bridges between the microanatomical computational circuitry and the atypical behaviours that arise when that circuitry is modified. In addition, it will allow us to better exploit the constructional plasticity within the brain to design more targeted interventions that better manage atypical cortical construction and that can be applied very early in postnatal life.


Subject(s)
Autism Spectrum Disorder , Cerebral Cortex/growth & development , Cerebral Cortex/pathology , Neural Pathways/growth & development , Neural Pathways/pathology , Humans
5.
FEMS Yeast Res ; 16(7)2016 11.
Article in English | MEDLINE | ID: mdl-27609602

ABSTRACT

By two-dimensional gel electrophoresis (2-DE) and mass spectrometry, we have characterized the polypeptide species present in extracts obtained by 60% ethanol treatment of whole mature (48 h) biofilms formed by a reference strain (CAI4-URA3) and four Candida albicans null mutants for cell-wall-related genes (ALG5, CSA1, MNN9 and PGA10) Null mutants form fragile biofilms that appeared partially split and weakly attached to the substratum contrary to those produced by the reference strain. An almost identical, electrophoretic profile consisting of about 276 spots was visualized in all extracts examined. Proteomic analysis led to the identification of 131 polypeptides, corresponding to 86 different protein species, being the rest isoforms-83 displayed negative hydropathic indexes and 82 lack signal peptide. The majority of proteins appeared at pI between 4 and 6, and molecular mass between 10 and 94 kDa. The proteins identified belonged to the following Gene Ontology categories: 21.9% unknown molecular function, 16.2% oxidoreductase activity, 13.3% hydrolase activity and 41.8% distributed between other different GO categories. Strong defects in biofilm formation appreciated in the cell-wall mutant strains could be attributed to defects in aggregation due to abnormal cell wall formation rather than to differences in the biofilm extracellular matrix composition.


Subject(s)
Biofilms/growth & development , Candida albicans/chemistry , Candida albicans/genetics , Cell Wall/genetics , Extracellular Matrix/chemistry , Fungal Proteins/analysis , Proteome/analysis , Candida albicans/physiology , Electrophoresis, Gel, Two-Dimensional , Gene Deletion , Genes, Fungal , Mass Spectrometry
6.
Appl Psychophysiol Biofeedback ; 41(4): 405-420, 2016 12.
Article in English | MEDLINE | ID: mdl-27573986

ABSTRACT

Autism is a pervasive developmental disorder of childhood characterized by deficits in social interaction, language, and stereotyped behaviors along with a restricted range of interests. It is further marked by an inability to perceive and respond to social and emotional signals in a typical manner. This might due to the functional disconnectivity of networks important for specific aspects of social cognition and behavioral control resulting in deficits of sensory information integration. According to several recent theories sensory processing and integration abnormalities may play an important role in impairments of perception, cognition, and behavior in individuals with autism. Among these sensory abnormalities, auditory perception distortion may contribute to many typical symptoms of autism. The present study used Berard's technique of auditory integration training (AIT) to improve sound integration in children with autism. It also aimed to understand the abnormal neural and functional mechanisms underlying sound processing distortion in autism by incorporating behavioral, psychophysiological and neurophysiological outcomes. It was proposed that exposure to twenty 30-min AIT sessions (total 10 h of training) would result in improved behavioral evaluation scores, improve profile of cardiorespiratory activity, and positively affect both early [N1, mismatch negativity (MMN)] and late (P3) components of evoked potentials in auditory oddball task. Eighteen children with autism spectrum disorder (ASD) participated in the study. A group of 16 typically developing children served as a contrast group in the auditory oddball task. Autonomic outcomes of the study reflected a linear increase of heart rate variability measures and respiration rate. Comparison of evoked potential characteristics of children with ASD versus typically developing children revealed several group difference findings, more specifically, a delayed latency of N1 to rare and frequent stimuli, larger MMN; higher P3a to frequent stimuli, and at the same time delayed latency of P3b to rare stimuli in the autism group. Post-AIT changes in evoked potentials could be summarized as a decreased magnitude of N1 to rare stimuli, marginally lower negativity of MMN, and decrease of the P3a to frequent stimuli along with delayed latency and higher amplitude of the P3b to the rare stimuli. These evoked potential changes following completion of Berard AIT course are in a positive direction, making them less distinct from those recorded in age-matched group of typical children, thus could be considered as changes towards normalization. Parental questionnaires clearly demonstrated improvements in behavioral symptoms such as irritability, hyperactivity, repetitive behaviors and other important behavioral domains. The results of the study propose that more controlled research is necessary to document behavioral and psychophysiological changes resulting from Berard AIT and to provide explanation of the neural mechanisms of how auditory integration training may affect behavior and psychophysiological responses of children with ASD.


Subject(s)
Acoustic Stimulation/methods , Autism Spectrum Disorder/therapy , Evoked Potentials/physiology , Adolescent , Autism Spectrum Disorder/physiopathology , Child , Electroencephalography/methods , Female , Humans , Male , Reaction Time/physiology , Surveys and Questionnaires
7.
Appl Psychophysiol Biofeedback ; 41(1): 47-60, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26341093

ABSTRACT

Autism spectrum disorder (ASD) is a developmental disorder marked by difficulty in social interactions and communication. ASD also often present symptoms of autonomic nervous system (ANS) functioning abnormalities. In individuals with autism the sympathetic branch of the ANS presents an over-activation on a background of the parasympathetic activity deficits, creating an autonomic imbalance, evidenced by a faster heart rate with little variation and increased tonic electrodermal activity. The objective of this study was to explore the effect of 12 sessions of 0.5 Hz repetitive transcranial magnetic stimulation (rTMS) over dorsolateral prefrontal cortex (DLPFC) on autonomic activity in children with ASD. Electrocardiogram and skin conductance level (SCL) were recorded and analyzed during each session of rTMS. The measures of interest were time domain (i.e., R-R intervals, standard deviation of cardiac intervals, NN50-cardio-intervals >50 ms different from preceding interval) and frequency domain heart rate variability (HRV) indices [i.e., power of high frequency (HF) and low frequency (LF) components of HRV spectrum, LF/HF ratio]. Based on our prior pilot studies it was proposed that the course of 12 weekly inhibitory low-frequency rTMS bilaterally applied to the DLPFC will improve autonomic balance probably through improved frontal inhibition of the ANS activity, and will be manifested in an increased length of cardiointervals and their variability, and in higher frequency-domain HRV in a form of increased HF power, decreased LF power, resulting in decreased LF/HF ratio, and in decreased SCL. Our post-12 TMS results showed significant increases in cardiac intervals variability measures and decrease of tonic SCL indicative of increased cardiac vagal control and reduced sympathetic arousal. Behavioral evaluations showed decreased irritability, hyperactivity, stereotype behavior and compulsive behavior ratings that correlated with several autonomic variables.


Subject(s)
Autism Spectrum Disorder/therapy , Autonomic Nervous System Diseases/therapy , Galvanic Skin Response/physiology , Heart Rate/physiology , Prefrontal Cortex/physiopathology , Transcranial Magnetic Stimulation/methods , Adolescent , Adult , Autism Spectrum Disorder/physiopathology , Autonomic Nervous System Diseases/physiopathology , Child , Electrocardiography , Female , Humans , Male , Treatment Outcome , Young Adult
8.
Appl Psychophysiol Biofeedback ; 41(1): 81-92, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26377686

ABSTRACT

Abnormalities in motor skills have been regarded as part of the symptomatology characterizing autism spectrum disorder (ASD). It has been estimated that 80 % of subjects with autism display "motor dyspraxia" or clumsiness that are not readily identified in a routine neurological examination. In this study we used behavioral measures, event-related potentials (ERP), and lateralized readiness potential (LRP) to study cognitive and motor preparation deficits contributing to the dyspraxia of autism. A modified Posner cueing task was used to analyze motor preparation abnormalities in children with autism and in typically developing children (N = 30/per group). In this task, subjects engage in preparing motor response based on a visual cue, and then execute a motor movement based on the subsequent imperative stimulus. The experimental conditions, such as the validity of the cue and the spatial location of the target stimuli were manipulated to influence motor response selection, preparation, and execution. Reaction time and accuracy benefited from validly cued targets in both groups, while main effects of target spatial position were more obvious in the autism group. The main ERP findings were prolonged and more negative early frontal potentials in the ASD in incongruent trials in both types of spatial location. The LRP amplitude was larger in incongruent trials and had stronger effect in the children with ASD. These effects were better expressed at the earlier stages of LRP, specifically those related to response selection, and showed difficulties at the cognitive phase of stimulus processing rather that at the motor execution stage. The LRP measures at different stages reflect the chronology of cognitive aspects of movement preparation and are sensitive to manipulations of cue correctness, thus representing very useful biomarker in autism dyspraxia research. Future studies may use more advance and diverse manipulations of movement preparation demands in testing more refined specifics of dyspraxia symptoms to investigate functional connectivity abnormalities underlying motor skills deficits in autism.


Subject(s)
Apraxias/physiopathology , Attention/physiology , Autism Spectrum Disorder/physiopathology , Cues , Motor Activity/physiology , Psychomotor Performance/physiology , Space Perception/physiology , Adolescent , Adult , Apraxias/etiology , Autism Spectrum Disorder/complications , Child , Electroencephalography , Evoked Potentials , Humans , Visual Perception , Young Adult
9.
Brain ; 137(Pt 7): 1863-75, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24531625

ABSTRACT

The prefrontal cortex of the primate brain has a modular architecture based on the aggregation of neurons in minicolumnar arrangements having afferent and efferent connections distributed across many brain regions to represent, select and/or maintain behavioural goals and executive commands. Prefrontal cortical microcircuits are assumed to play a key role in the perception to action cycle that integrates relevant information about environment, and then selects and enacts behavioural responses. Thus, neurons within the interlaminar microcircuits participate in various functional states requiring the integration of signals across cortical layers and the selection of executive variables. Recent research suggests that executive abilities emerge from cortico-cortical interactions between interlaminar prefrontal cortical microcircuits, whereas their disruption is involved in a broad spectrum of neurologic and psychiatric disorders such as autism, schizophrenia, Alzheimer's and drug addiction. The focus of this review is on the structural, functional and pathological approaches involving cortical minicolumns. Based on recent technological progress it has been demonstrated that microstimulation of infragranular cortical layers with patterns of microcurrents derived from supragranular layers led to an increase in cognitive performance. This suggests that interlaminar prefrontal cortical microcircuits are playing a causal role in improving cognitive performance. An important reason for the new interest in cortical modularity comes from both the impressive progress in understanding anatomical, physiological and pathological facets of cortical microcircuits and the promise of neural prosthetics for patients with neurological and psychiatric disorders.


Subject(s)
Cognition Disorders/pathology , Executive Function/physiology , Prefrontal Cortex/pathology , Prefrontal Cortex/physiopathology , Humans
10.
Acta Paediatr ; 104(4): 346-55, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25626149

ABSTRACT

UNLABELLED: Postmortem studies in autism spectrum disorder (ASD) individuals indicate the presence of abnormalities within the peripheral neuropil space (PNS) of cortical minicolumns. The geometrical orientation of inhibitory elements within the PNS suggests using repetitive transcranial magnetic stimulation (rTMS) to up-regulate their activity. Several rTMS trials in ASD have shown marked improvements in motor symptomatology, attention and perceptual binding. CONCLUSION: rTMS is the first therapeutic attempt at ASD aimed at correcting some of its core pathology.


Subject(s)
Autism Spectrum Disorder/therapy , Transcranial Magnetic Stimulation , Autism Spectrum Disorder/pathology , Cerebral Cortex/pathology , Child , Humans
11.
Environ Monit Assess ; 187(11): 697, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26490735

ABSTRACT

There are concerns about the impact of maize cultivation with high applications of nitrogen (N) and phosphorus (P) on water quality in surface waters in Mediterranean Central Chile. This study estimated the contribution of N and P from maize fields to nearby drainage channels and evaluated the effects in water quality. An N and P budget was drawn up for three fields managed with a maize-fallow system, El Maitén (20.7 ha), El Naranjal (14.9 ha) and El Caleuche (4.2 ha), and water quality variables (pH, EC, dissolved oxygen, total solids, turbidity, NO3-N, NH4-N, PO4(3-), COD, total N, total P and sulphate) were monitored in nearby drainage channels. The N and P balances for the three fields indicated a high risk of N and P non-point source pollution, with fertiliser management, soil texture and climate factors determining the temporal variations in water quality parameters. Elevated levels of NH4-N and PO4(3-) in the drainage channels were usually observed during the winter period, while NO3- concentrations did not show a clear tendency. The results suggest that excessive slurry application during winter represents a very high risk of N and P runoff to drainage channels. Overall, great emphasis must be placed on good agronomic management of fields neighbouring drainage channels, including accurately calculating N and P fertiliser rates and establishing mitigation measures.


Subject(s)
Agricultural Irrigation , Environmental Monitoring , Nitrogen/analysis , Phosphorus/analysis , Water Pollutants, Chemical/analysis , Zea mays/growth & development , Chile , Fertilizers/analysis , Water
12.
J Neurosci Res ; 92(7): 927-36, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24692022

ABSTRACT

Valproic acid (VPA) is commonly used to treat bipolar disorder (BD), but its therapeutic role has not been clearly elucidated. To gain insights into VPA's mechanism of action, proteomic analysis was used to identify differentially expressed proteins in the rat prefrontal cortex (PFC), a region particularly affected in BD, after 6 weeks of VPA treatment. Proteins from PFCs of control and VPA-treated rats were separated by 2D-DIGE and identified by mass spectrometry. Among the 2,826 protein spots resolved, the abundance of 19 proteins was found to be significantly altered in the VPA-treated group (with the levels of three proteins increasing and 16 decreasing). Seven proteins whose levels were significantly altered after chronic VPA exposure were quantified by Western blot analysis. The 19 identified proteins represent potential new targets for VPA action and should aid in our understanding of the role of VPA in BD.


Subject(s)
Anticonvulsants/metabolism , Nerve Tissue Proteins/metabolism , Prefrontal Cortex/drug effects , Proteomics/methods , Valproic Acid/pharmacology , Animals , Electrophoresis, Gel, Two-Dimensional , Gene Expression Regulation/drug effects , Male , Models, Biological , Prefrontal Cortex/metabolism , Protein Interaction Maps/drug effects , Rats , Rats, Sprague-Dawley , Time Factors
13.
Appl Psychophysiol Biofeedback ; 39(3-4): 237-57, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25267414

ABSTRACT

Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, language, stereotyped behaviors, and restricted range of interests. In previous studies low frequency repetitive transcranial magnetic stimulation (rTMS) has been used, with positive behavioral and electrophysiological results, for the experimental treatment in ASD. In this study we combined prefrontal rTMS sessions with electroencephalographic (EEG) neurofeedback (NFB) to prolong and reinforce TMS-induced EEG changes. The pilot trial recruited 42 children with ASD (~14.5 years). Outcome measures included behavioral evaluations and reaction time test with event-related potential (ERP) recording. For the main goal of this exploratory study we used rTMS-neurofeedback combination (TMS-NFB, N = 20) and waitlist (WTL, N = 22) groups to examine effects of 18 sessions of integrated rTMS-NFB treatment or wait period) on behavioral responses, stimulus and response-locked ERPs, and other functional and clinical outcomes. The underlying hypothesis was that combined TMS-NFB will improve executive functions in autistic patients as compared to the WTL group. Behavioral and ERP outcomes were collected in pre- and post-treatment tests in both groups. Results of the study supported our hypothesis by demonstration of positive effects of combined TMS-NFB neurotherapy in active treatment group as compared to control WTL group, as the TMS-NFB group showed significant improvements in behavioral and functional outcomes as compared to the WTL group.


Subject(s)
Brain Waves/physiology , Child Development Disorders, Pervasive/therapy , Evoked Potentials/physiology , Executive Function/physiology , Neurofeedback/methods , Transcranial Magnetic Stimulation/methods , Adolescent , Adult , Child , Child Development Disorders, Pervasive/physiopathology , Female , Humans , Male , Pilot Projects , Treatment Outcome , Young Adult
14.
J Neurosci ; 32(34): 11864-78, 2012 Aug 22.
Article in English | MEDLINE | ID: mdl-22915127

ABSTRACT

Deficits in social and communication behaviors are common features of a number of neurodevelopmental disorders. However, the molecular and cellular substrates of these higher order brain functions are not well understood. Here we report that specific alterations in social and communication behaviors in mice occur as a result of loss of the EPAC2 gene, which encodes a protein kinase A-independent cAMP target. Epac2-deficient mice exhibited robust deficits in social interactions and ultrasonic vocalizations, but displayed normal olfaction, working and reference memory, motor abilities, anxiety, and repetitive behaviors. Epac2-deficient mice displayed abnormal columnar organization in the anterior cingulate cortex, a region implicated in social behavior in humans, but not in somatosensory cortex. In vivo two-photon imaging revealed reduced dendritic spine motility and density on cortical neurons in Epac2-deficient mice, indicating deficits at the synaptic level. Together, these findings provide novel insight into the molecular and cellular substrates of social and communication behavior.


Subject(s)
Dendritic Spines/genetics , Guanine Nucleotide Exchange Factors/deficiency , Neurons/cytology , Social Behavior , Somatosensory Cortex/cytology , Vocalization, Animal/physiology , Animals , Dendritic Spines/physiology , Exploratory Behavior/physiology , Female , Green Fluorescent Proteins/metabolism , Guanine Nucleotide Exchange Factors/genetics , Locomotion/genetics , Male , Maze Learning/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Statistics, Nonparametric
15.
Brain Sci ; 13(1)2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36672111

ABSTRACT

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that interferes with normal brain development. Brain connectivity may serve as a biomarker for ASD in this respect. This study enrolled a total of 179 children aged 3-10 years (90 typically developed (TD) and 89 with ASD). We used a weighted phase lag index and a directed transfer function to investigate the functional and effective connectivity in children with ASD and TD. Our findings indicated that patients with ASD had local hyper-connectivity of brain regions in functional connectivity and simultaneous significant decrease in effective connectivity across hemispheres. These connectivity abnormalities may help to find biomarkers of ASD.

16.
Bioengineering (Basel) ; 10(1)2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36671670

ABSTRACT

Autism spectrum disorder (ASD) is a heterogeneous disorder that affects several behavioral domains of neurodevelopment. Transcranial direct current stimulation (tDCS) is a new method that modulates motor and cognitive function and may have potential applications in ASD treatment. To identify its potential effects on ASD, differences in electroencephalogram (EEG) microstates were compared between children with typical development (n = 26) and those with ASD (n = 26). Furthermore, children with ASD were divided into a tDCS (experimental) and sham stimulation (control) group, and EEG microstates and Autism Behavior Checklist (ABC) scores before and after tDCS were compared. Microstates A, B, and D differed significantly between children with TD and those with ASD. In the experimental group, the scores of microstates A and C and ABC before tDCS differed from those after tDCS. Conversely, in the control group, neither the EEG microstates nor the ABC scores before the treatment period (sham stimulation) differed from those after the treatment period. This study indicates that tDCS may become a viable treatment for ASD.

17.
J Pers Med ; 13(3)2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36983738

ABSTRACT

The BRAIN Foundation (Pleasanton, CA, USA) hosted Synchrony 2022, a translational medicine conference focused on research into treatments for individuals with neurodevelopmental disorders (NDD), including those with autism spectrum disorders (ASD) [...].

18.
Front Neurosci ; 17: 1277786, 2023.
Article in English | MEDLINE | ID: mdl-38274502

ABSTRACT

Introduction: Many studies have collected normative developmental EEG data to better understand brain function in early life and associated changes during both aging and pathology. Higher cognitive functions of the brain do not normally stem from the workings of a single brain region that works but, rather, on the interaction between different brain regions. In this regard studying the connectivity between brain regions is of great importance towards understanding higher cognitive functions and its underlying mechanisms. Methods: In this study, EEG data of children (N = 253; 3-10 years old; 113 females, 140 males) from pre-school to schoolage was collected, and the weighted phase delay index and directed transfer function method was used to find the electrophysiological indicators of both functional connectivity and effective connectivity. A general linear model was built between the indicators and age, and the change trend of electrophysiological indicators analyzed for age. Results: The results showed an age trend for the functional and effective connectivity of the brain of children. Discussion: The results are of importance in understanding normative brain development and in defining those conditions that deviate from typical growth trajectories.

19.
Appl Psychophysiol Biofeedback ; 37(2): 91-102, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22311204

ABSTRACT

One important executive function known to be compromised in autism spectrum disorder (ASD) is related to response error monitoring and post-error response correction. Several reports indicate that children with ASD show reduced error processing and deficient behavioral correction after an error is committed. Error sensitivity can be readily examined by measuring event-related potentials (ERP) associated with responses to errors, the fronto-central error-related negativity (ERN), and the error-related positivity (Pe). The goal of our study was to investigate whether reaction time (RT), error rate, post-error RT change, ERN, and Pe will show positive changes following 12-week long slow frequency repetitive TMS (rTMS) over dorsolateral prefrontal cortex (DLPFC) in high functioning children with ASD. We hypothesized that 12 sessions of 1 Hz rTMS bilaterally applied over the DLPFC will result in improvements reflected in both behavioral and ERP measures. Participants were randomly assigned to either active rTMS treatment or wait-list (WTL) groups. Baseline and post-TMS/or WTL EEG was collected using 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. ERN in TMS treatment group became significantly more negative. The number of omission errors decreased post-TMS. The RT did not change, but post-error RT became slower. There were no changes in RT, error rate, post-error RT slowing, nor in ERN/Pe measures in the wait-list group. Our results show significant post-TMS differences in the response-locked ERP such as ERN, as well as behavioral response monitoring measures indicative of improved error monitoring and correction function. The ERN and Pe, along with behavioral performance measures, can be used as functional outcome measures to assess the effectiveness of neuromodulation (e.g., rTMS) in children with autism and thus may have important practical implications.


Subject(s)
Autistic Disorder/psychology , Autistic Disorder/rehabilitation , Prefrontal Cortex/physiology , Psychomotor Performance/physiology , Self Concept , Transcranial Magnetic Stimulation , Adolescent , Child , Child Behavior , Data Interpretation, Statistical , Diagnostic and Statistical Manual of Mental Disorders , Electroencephalography , Electrooculography , Evoked Potentials/physiology , Female , Humans , Intelligence Tests , Male , Neuropsychological Tests , Reaction Time/physiology , Transcranial Magnetic Stimulation/instrumentation , Transcranial Magnetic Stimulation/methods , Young Adult
20.
Med Biol Eng Comput ; 60(12): 3655-3664, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36282407

ABSTRACT

To compare the differences in directed connectivity between typically developing (TD) and autism spectrum disorder (ASD) children and identify the potential effects of repetitive transcranial magnetic stimulation (rTMS) on brain connectivity and behavior of children with ASD; 26 TD children (18 males/8 females; the average age was 6.34 ± 0.45) and 30 ASD children (21 males/9 females; the average age was 6.42 ± 0.17) participated in the experiment. ASD children were divided randomly into an experimental group and a control group. The experimental group received 18 rTMS sessions (twice a week for nine weeks), whereas the control group received the same procedures with sham stimulation. Directed transfer function (DTF) was used to calculate the effective connectivity as a way of investigating differences between ASD and TD children while simultaneously evaluating the effectiveness of rTMS for ASD. The results illustrate that the DTF of TD children in the frontal lobe (Fp1, Fp2, F7, F8) and temporal lobe (T7, T8) is higher than that of ASD children in all frequency bands; however, the DTF of ASD children is higher than TD in the midline (Fz, Cz), central lobe (C3, C4), and parietal lobe (P3, P4). In the experimental group of ASD children, the effective connectivity decreased from O1 to T7 and from P7 to Fp1 in the alpha band and from Pz to T8 in the gamma band after stimulation. Significant changes in Autism Behavior Checklist (ABC) scores were also found in social behaviors. Effective connectivity derived from DTF distinguishes ASD from TD children. rTMS provides changes in connectivity and behavior, suggesting its potential use as a viable treatment option for ASD individuals.


Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Child , Male , Female , Humans , Child, Preschool , Transcranial Magnetic Stimulation/methods , Autistic Disorder/therapy , Autism Spectrum Disorder/therapy , Pilot Projects , Brain/physiology , Electroencephalography/methods
SELECTION OF CITATIONS
SEARCH DETAIL