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A variety of cardiomyopathies are due to familial disease. Most are primarily associated with cardiac involvement and can lead to hypertrophic, dilated, or restrictive cardiomyopathy. Myotonic dystrophy (MD) is a multisystem disease with autosomal dominant inheritance and variable penetrance. Cardiac diseases are important causes of morbidity and mortality in MD patients. Patients with primary MD should be carefully investigated with an electrocardiogram, stress test, and an echocardiogram to identify preclinical cardiac involvement and to prevent life-threatening complications. Any new onset of atrial flutter or atrial fibrillation in a young patient without any underlying cardiac abnormality should be investigated for underlying myopathy. The authors report on a male adolescent with MD who presented with atrial flutter. The patient had been diagnosed with MD at birth. He had an impaired ejection fraction of 38% to 45%. The patient described sharp chest pain in the retrosternal area, with no radiation, that was induced by exercise.

The rapidly growing volume of electrophysiological signals has been generated for clinical research in neurological disorders. European Data Format (EDF) is a standard format for storing electrophysiological signals. However, the bottleneck of existing signal analysis tools for handling large-scale datasets is the sequential way of loading large EDF files before performing an analysis. To overcome this, we develop Hadoop-EDF, a distributed signal processing tool to load EDF data in a parallel manner using Hadoop MapReduce. Hadoop-EDF uses a robust data partition algorithm making EDF data parallel processable. We evaluate Hadoop-EDF’s scalability and performance by leveraging two datasets from the National Sleep Research Resource and running experiments on Amazon Web Service clusters. The performance of Hadoop-EDF on a 20-node cluster improves 27 times and 47 times than sequential processing of 200 small-size files and 200 large-size files, respectively. The results demonstrate that Hadoop-EDF is more suitable and effective in processing large EDF files.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成4年10月19日 狩野良雄氏の博士論文として提出された

Over thirty years ago electrical coupling was observed in embryonic cells prior to chemical communication. This temporal relationship of electrical coupling preceding functional chemical neurotransmission occurs throughout neurogenesis, prompting the idea that gap junctional coupling synchronizes the synaptogenic establishment of functional neural networks. Helisoma neuronal pairs treated with trophic factors exhibit increased electrical coupling and subsequently delay the formation of inhibitory chemical connections. Studies in this thesis addressed the mechanism regulating this inverse relationship between electrotonic and chemical communication. Synaptogenesis between two neurons from the Helisoma buccal ganglia, B110 and B19, were examined using alternative culturing conditions that were either exposed to or deprived of trophic factors. Incubating neuronal pairs in trophic factors induced transient electrical synapses and postponed the formation of chemical connections. In electrically coupled neuronal pairs, presynaptic secretory vesicles were recruited to the sites of presynaptic contact, but did not respond to calcium elevation (i.e., photolytic release of calcium from NP-EGTA) with neurotransmitter release. These and other studies demonstrated that transient electrical coupling does not disrupt calcium handling or postsynaptic responsiveness. Rather, electrotonic coupling delays chemical synaptic transmission by imposing a functional block between the accumulation of presynaptic calcium and the synchronized vesicular release of neurotransmitter.

Background: Recently there has been a revitalization in research on classic psychedelic substances. This class of drugs has been found to produce intense and profoundly meaningful experiences, and offers a unique opportunity to study the neural correlates of the sense of self. The objective of this research was to systematically review the effects of classic psychedelics on spontaneous brain activity, as measured on three electrophysiological modalities: spectral analysis, signal diversity, and functional connectivity. Method: We searched Pubmed to identify papers in English, published between January 1990 to May 2021, where electrophysiological methods were used to evaluate the effects of classic psychedelics in healthy individuals during non-task resting states. Results: Sixteen papers were included. Classic psychedelic substances generally decrease spectral power in most frequency bands, mainly in the alpha range, increase signal diversity, and decrease the flow of information throughout the brain. Conclusion: Decreases in alpha power, increased signal diversity, and decreases in default mode network activity might be important neural correlates of the psychedelic state. However, inconsistencies in the results and heterogeneity in study design are some of the limitations that have to be considered when interpreting these results.

The electrophysiological and morphological properties of small networks of mammalian neurons were investigated with mouse spinal cord monolayer cultures of 2 mm diameter grown on multimicroelectrode plates (MMEPs). Such cultures were viewed microscopically and their activity simultaneously recorded from 2 of any 36 fixed recording sites. The specific aims achieved were: development of techniques for production of functional MMEPs and maintenance of mini-cultures, characterization of the spontaneous activity of mini-cultures, application of inhibitory and disinhibitory agents, development of staining methods for cultured neurons and initial light microscopic analysis with correlation of electrophysiological and morphological characteristics.

>Magister Scientiae - MSc / INTRODUCTION: Sustained attention is known to be dysfunctional in psychotic disorders. Sustained attention is the ability to remain focused on a specific time-locked stimulus within a task. We aimed to determine whether there are specific group differences between CON and three psychotic disorders: SCZ, MPD and BPD, then to determine differences between these psychotic disorders. This included differences in behavioural performance and prominent electrophysiological event-related potential (ERP) wave components during cueing and target processing of a visual sustained attention task. Further we aimed to characterize ERP waveform component relationships across and within these groups for demographics, substance use, behavioural performance, and clinical variables, the last limited to the psychotic groups. Lastly, we investigated the effects of prescribed medications on ERP wave components within the psychotic groups. METHODOLOGY: 103 participants (29 schizophrenia (SCZ), 28 bipolar disorder with a history of psychosis (BPD), 21 methamphetamine-induced psychotic disorder (MPD), and 30 controls (CON)) underwent electroencephalography (EEG) record while completing a visual continuous performance task. Participants were presented with 60 trials with three consecutive S’s, the presentation of the third S required a behavioural response. Prominent ERP waveform components were extracted from cues and target stimulus. Group differences were determined by ANOVA with Bonferroni post-hoc correction or multivariate Kruskal-Wallis test dependent on data distribution. Relationships between ERP wave components were determined appropriate with Spearman’s Rank order correlation analyses. RESULTS: (1) MPD reported higher use of substances compared to CON, SCZ and BPD. SCZ behavioural performance was poorer compared to CON which was shown by their longer response times, reduced accuracy and increased errors of omission. Clinically, MPD was found to have a shorter duration of illness compared to SCZ. Then SCZ was found to have more positive symptoms compared to BPD whereas BPD had more negative symptoms compared to SCZ. For the first cue, wave component differences were found only over the left hemisphere, for P100 amplitude over the frontal cortex, P300 amplitude over the central cortex, and N170 amplitude over the parietal cortex. For the presentation of the second cue, differences noted for all groups were localised to the frontal and central brain regions, for P100 and N170 ERP waveforms. For the target stimulus wave component differences were found over the prefrontal, frontal and parietal brain regions, within CON, SCZ, BPD and MPD. (2) For the first cue, education positively correlated with the N170 left parietal amplitude in CON and P300 right parietal amplitude in MPD. During the second cue, the left parietal N170 latency in SCZ correlated positively with education and the left central P300 latency correlated negatively with education in MPD. The age on the day of testing correlated positively with the target left frontal P300 latency in MPD. For the first cue, substance use positively correlated with the left and right parietal P300 latency and negatively for the right parietal P100 amplitude in SCZ. In MPD, a negative correlation was noted across left and right prefrontal N170 and P300 amplitudes, and positive correlation for the left prefrontal P300 latency in MPD. For the target stimulus, correlations were evident for the left and right parietal N70, N170 amplitudes, P300 latency, the right parietal P100 amplitude and left central P300 latency in SCZ. For the first cue, in SCZ PANSS total score correlated positively with left and right central P300 amplitudes and the left parietal P300 amplitude. For the second cue; in MPD, the PANSS negative symptom score, positively correlated with the P100 and N170 left parietal amplitude, left and right parietal P150 amplitude, left central and right parietal P300 amplitude. For the target, the Hamilton depression rating scale correlated positively with the left and right frontal P300 amplitude in MPD and then negatively with the right parietal P300 amplitude in SCZ. Behavioural performance in CON, positively correlated with the left parietal N70, P100, P150 and N170 amplitude the number of correct responses, and left central N170 amplitude. While the number of impulsive responses correlated negatively with the left parietal N70, P100, P150 and N170 and the left central N170 amplitude of CON. For the second cue, behavioural performance was related to the fronto-parietal relationship across all groups. For the target stimulus, impulsive responses positively correlated with the left parietal N70 latency in SCZ. Overall response time negatively correlated with the right parietal P300 latency for SCZ. (3) Medication was found to affect ERP wave components during the sustained visual attention task. For the first cue FGA’s increased the left central P100 amplitude in both SCZ and BPD and decreased the left parietal P100 amplitude in SCZ only. The use of antipsychotics increased the right parietal N70 and left central P100 amplitudes in BPD, specifically the right prefrontal N170 amplitude was increased with the use of SGA’s. Then clozapine use increased the left frontal P100 amplitude in SCZ. For the second cue, SGA’s decreased the right parietal P150 amplitude in SCZ but in MPD the right parietal P150 amplitude was increased with haloperidol use, and FGA. SGA’s increased the left parietal P300 latency in BPD and sodium valproate decreased the left prefrontal P300 latency. For the target stimulus, SGA’s decreased the right parietal P100, P150 and left parietal P150 amplitudes and increased the left central P300 latency in BPD. CONCLUSION: (1) sustained attentional performance is poorer in SCZ. Our study adds to previous studies showing attention processing deficits in SCZ, are evident during cueing of a sustained attention tasks; (2) substance use was found to slow cognitive processing, education improved executive function and information processing, and symptom severity was associated with dysfunction of prefrontal and frontal cortices; (3) antipsychotic medication was related to improved processing of salient information. These data support the current literature and provide novel insights to the attentional processing deficits during cueing in the psychotic disorders.

>Magister Scientiae - MSc / Introduction: Sustained attention is known to be dysfunctional in psychotic disorders. Sustained attention is the ability to remain focused on a specific time-locked stimulus within a task. We aimed to determine whether there are specific group differences between CON and three psychotic disorders: SCZ, MPD and BPD, then to determine differences between these psychotic disorders. This included differences in behavioural performance and prominent electrophysiological event-related potential (ERP) wave components during cueing and target processing of a visual sustained attention task. Further we aimed to characterize ERP waveform component relationships across and within these groups for demographics, substance use, behavioural performance, and clinical variables, the last limited to the psychotic groups. Lastly, we investigated the effects of prescribed medications on ERP wave components within the psychotic groups. Methodology: 103 participants (29 schizophrenia (SCZ), 28 bipolar disorder with a history of psychosis (BPD), 21 methamphetamine-induced psychotic disorder (MPD), and 30 controls (CON)) underwent electroencephalography (EEG) record while completing a visual continuous performance task. Participants were presented with 60 trials with three consecutive S’s, the presentation of the third S required a behavioural response. Prominent ERP waveform components were extracted from cues and target stimulus. Group differences were determined by ANOVA with Bonferroni post-hoc correction or multivariate Kruskal-Wallis test dependent on data distribution. Relationships between ERP wave components were determined appropriate with Spearman’s Rank order correlation analyses.

O P300 auditivo é um potencial evocado que reflete a atividade neurofisiológica das habilidades cognitivas auditivas de atenção, memória, discriminação e tomada de decisão. A possibilidade de correlacionar aspectos do comportamento auditivo a fenômenos fisiológicos observáveis tem despertado o interesse de profissionais de diversas áreas interessados no estudo das disfunções auditivas. Por ser um procedimento novo, os métodos de análise e interpretação dos resultados ainda não estão padronizados e, portanto, devem ser explorados e discutidos visando maior segurança para aplicação clínica e científica. Este estudo investigou a estabilidade na análise e interpretação do P300 auditivo seguindo um conjunto de regras (critério) pré-determinadas. Para isso, quatro profissionais da área audiológica analisaram, em 2 momentos diferentes, 70 traçados de P300 de crianças e adolescentes saudáveis entre 8 e 18 anos de idade, seguindo as mesmas regras para a identificação das ondas (N1, P2, N2 e P3) e marcação de suas medidas de latência. As medidas de latência da onda P300 foram submetidas a análises qualitativa e quantitativa. A análise qualitativa investigou os tipos de erros cometidos pelo examinador no uso do critério de determinação do P300 (5,9% do total de 560 medidas obtidas). Os erros mais freqüentes no uso do critério foram: não identificar o P300 como a maior onda logo após o complexo N1-P2-N2 e identificar uma “falsa" onda P300. A análise quantitativa investigou a variabilidade da medida da latência do P300 atribuível ao examinador. Os resultados mostraram que não houve diferença significante entre as análises inter e intra-examinador, tendo sido encontradas correlações significantes entre as medidas de latência, indicando boa fidedignidade no teste-reteste e alta concordância entre os examinadores no modo como analisaram os traçados das ondas. O critério usado neste estudo demonstrou ser útil na determinação do P300, podendo ser sugerido com segurança para uso clínico e científico. / The P300 auditory is an evoked potential which reflects the neurophysiological activity of auditory cognitive abilities: attention, memory, discrimination and making decision as well. The possibility of correlation between aspects of auditory behavior and observable physiological phenomena has increased the interest in the study of auditory dysfunctions among professionals of various fields. Due the fact that the P300 is a recent procedure, the methods of its analysis and interpretation have not been standardized yet. Therefore, they must be explored and debated aiming more security for clinical and scientific application. In this study it was investigated the stability in the analysis and interpretation of P300 auditory, according to a pre-determined set of rules. Four audiologists analyzed twice 70 records of P300 of healthy children and adolescents between 8 and 18 years of age, identifying the waves (N1, P2, N2, P3) and their latencies according to the pre-determined set of rule. The P300 latency measurements were submitted to quantitative and qualitative analysis. The qualitative analysis looked into types of errors made by the examiner during the P300 identification (5.9% in a total of 560 measurements). The no-identification of the P300 as the highest wave following the complex N1-P2-N2, likewise the “wrong" identification of P300 wave were the most frequent mistakes. In the quantitative analysis we investigated the variability of the P300 latency measurements attributable to the examiner. The results showed that there were no significant differences between the inter- and intra-examiner analyses. Significant correlations were found between the measurements, showing a good test-retest reliability and high concordance among the examiners in the way they analyzed the wave records. We conclude that the rules used in this study are useful to the identification of the P300 in both clinical and scientific situations.