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Find video protocols related to scientific articles indexed in Pubmed.
Spectroscopic and computational study of a nonheme iron nitrosyl center in a biosynthetic model of nitric oxide reductase.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 01-31-2014
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A major barrier to understanding the mechanism of nitric oxide reductases (NORs) is the lack of a selective probe of NO binding to the nonheme FeB center. By replacing the heme in a biosynthetic model of NORs, which structurally and functionally mimics NORs, with isostructural ZnPP, the electronic structure and functional properties of the FeB nitrosyl complex was probed. This approach allowed observation of the first S=3/2 nonheme {FeNO}(7) complex in a protein-based model system of NOR. Detailed spectroscopic and computational studies show that the electronic state of the {FeNO}(7) complex is best described as a high spin ferrous iron (S=2) antiferromagnetically coupled to an NO radical (S=1/2) [Fe(2+)-NO(.)]. The radical nature of the FeB -bound NO would facilitate N-N bond formation by radical coupling with the heme-bound NO. This finding, therefore, supports the proposed trans mechanism of NO reduction by NORs.
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A review on telemedicine-based WBAN framework for patient monitoring.
Telemed J E Health
PUBLISHED: 07-10-2013
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In this article, we describe the important aspects like major characteristics, research issues, and challenges with body area sensor networks in telemedicine systems for patient monitoring in different scenarios. Present and emerging developments in communications integrated with the developments in microelectronics and embedded system technologies will have a dramatic impact on future patient monitoring and health information delivery systems. The important challenges are bandwidth limitations, power consumption, and skin or tissue protection.
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Short- and long-latency interhemispheric inhibitions are additive in human motor cortex.
J. Neurophysiol.
PUBLISHED: 03-27-2013
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Transcranial magnetic stimulation (TMS) of the human primary motor cortex (M1) at suprathreshold strength results in inhibition of M1 in the opposite hemisphere, a process termed interhemispheric inhibition (IHI). Two phases of IHI, termed short-latency interhemispheric inhibition (SIHI) and long-latency interhemispheric inhibition (LIHI), involving separate neural circuits, have been identified. In this study we evaluated how these two inhibitory processes interact with each other. We studied 10 healthy right-handed subjects. A test stimulus (TS) was delivered to the left M1, and motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous (FDI) muscle. Contralateral conditioning stimuli (CCS) were applied to the right M1 either 10 ms or 50 ms prior to the TS, inducing SIHI and LIHI, respectively, in the left M1. The effects of SIHI and LIHI alone, and SIHI and LIHI delivered together, were compared. The TS was adjusted to produce 1-mV or 0.5-mV MEPs when applied alone or after CCS. SIHI and LIHI were found to be additive when delivered together, irrespective of the strength of the TS. The interactions were affected neither by varying the strength of the conditioning stimulus producing SIHI nor by altering the current direction of the TS. Small or opposing interactions, however, may not have been detected. These results support previous findings suggesting that SIHI and LIHI act through different neural circuits. Such inhibitory processes may be used individually or additively during motor tasks and should be studied as separate processes in functional studies.
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A four-coordinate thionitrosyl complex of vanadium.
Chem. Commun. (Camb.)
PUBLISHED: 02-27-2013
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Addition of elemental sulfur to the vanadium nitride [(nacnac)V?N(OAr)] forms the first thionitrosyl complex of vanadium, [(nacnac)V(NS)(OAr)]. Single crystal X-Ray diffraction studies and DFT calculations reveal an almost linear thionitrosyl ligand resulting from an extended ?-resonance across the VNS moiety.
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A short term experience of management of open and osteoporotic intercondylar fractures of the distal humerus using a mini-external fixator.
J Indian Med Assoc
PUBLISHED: 10-20-2011
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Seven cases of intercondylar fractures of the distal humerus were treated by a mini-external fixation technique. The average range of motion was 30 degrees to 110 degrees. All fractures united with radiologic and clinical evidence of union at 10-12 weeks. Open wound sites healed in 6 cases. There were no evidence of any nerve palsies.
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Studies on Enders intramedullary nailing for closed tibial shaft fractures.
J Indian Med Assoc
PUBLISHED: 10-20-2011
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Low cost multiple flexible Enders nails can be used in tibial shaft fractures in a non-ideal operating room set-up in India, also because of easy methodology. It is commonly used in femur and humerus but not in tibia. So we made the study in which prospective and consecutive patients were taken based on selection criteria. Forty patients were treated by the technique from August 2004 to May 2006. Twenty-seven patients (67.5%) were male, 28 patients (70%) had fracture type 4-2A of AO classification, 37 patients (92.5%) had acute injuries, delay in surgery by 1-2 weeks in 21 patients (52.5%), 30 patients (75%) had closed nailing, 35 patients (87.5%) needed 2 nails, 36 patients (90%) were operated by antegrade nailing approach and 23 patients (57.5%) had fracture union within 16 weeks. All the patients were evaluated based on pain,range of movement of knee and ankle,shortening and radiological union along with ability to perform daily activities like squatting,sitting cross-legged and the ability to walk. There was excellent result in 34 patients (85%), good in 5 patients (12.5%), fair/poor result in 1 patient (2.5%). The complications observed were soft tissue irritation of the proximal part of tibia due to protruding nail in 5 patients,infection at the entry portal in one patient and non-union in one patient. Enders nailing can be a safe and alternative method of fixation of fracture shaft of tibia in rural India for poor patients in not well set-up.
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Brief electroencephalography rhythmic discharges (BERDs) in the neonate with seizures: their significance and prognostic implications.
J. Child Neurol.
PUBLISHED: 06-07-2011
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We aimed to explore the significance and prognostic implications of paroxysmal brief electroencephalography (EEG) rhythmic discharges (BERDs) in neonatal seizures. The 52 neonates in this study were divided into 3 groups: (1) BERDs only: 9 neonates, (2) BERDs + conventional EEG seizures: 11 babies, (3) Conventional EEG seizures only: 32 babies. We analyzed the BERDs and compared outcomes in the 3 groups: there was no significant difference in mortality and neurodevelopmental or background EEG impairment. Similar to conventional EEG seizures, BERDs are also associated with an increased mortality, morbidity, and EEG background abnormalities. Fewer babies with BERDS appear to develop postneonatal seizures suggesting their epileptogenic potential is less. In the appropriate clinical context, BERDs should be considered as miniseizures.
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Redox properties of Tanakas water oxidation catalyst: redox noninnocent ligands dominate the electronic structure and reactivity.
Inorg Chem
PUBLISHED: 06-02-2011
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[Ru(2)(OH)(2)(3,6-(t)Bu(2)Q)(2)(btpyan)](2+) ((t)Bu(2)Q, 3,6-di-tert-butyl-1,2-benzoquinone; btpyan, 1,8-bis(2,2:6,2-terpyridyl)anthracene) is one of a handful of structurally well-defined homogeneous catalysts that can electrocatalytically oxidize water at room temperature. Unfortunately, the exact composition and the chemical properties of the redox intermediates leading to the catalytically competent species remains poorly resolved. On the basis of the UV-vis spectra the catalyst was previously speculated to lose two protons spontaneously to form an intermediate containing the key O-O bond in water. We evaluated this mechanistic scenario computationally and found that the associated pK(a) values are in the range of 21, much too high to justify spontaneous deprotonation under experimental conditions of pH = 4. In later work, the O-O bond formation was speculated to occur after removal of two protons and two electrons. Extensive exploration of the various oxidation and protonation states that the diruthenium complex may access during catalyst activation reveals surprisingly complex electronic structure patterns in several redox intermediates: the quinone and tpy ligands become redox noninnocent, i.e., they participate actively in the electron transfer processes by temporarily storing redox equivalents. On the basis of this new insight into the electronic structure we propose a novel alternative explanation of the spectroscopic observations reported previously and characterize the electronic structure of the key intermediates in detail. Finally, the redox potential for the first two-electron oxidation is evaluated based on our proposed intermediates and predicted to be 0.411 V, which compares well with the experimentally observed broad two-electron wave at ?0.32 V.
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Classification of clinical semiology in epileptic seizures in neonates.
Eur. J. Paediatr. Neurol.
PUBLISHED: 03-10-2011
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The clinical semiology of 61 neonatal seizures with EEG correlates, in 24 babies was analysed. Most seizures (89%) had multiple features during the EEG discharge. The seizures were classified using the prominent clinical feature at onset, and all features seen during the seizure, using an extended classification scheme. Orolingual features occurred most frequently at onset (30%), whereas ocular phenomena occurred most often during the seizure (70%). Orolingual, ocular and autonomic features were seen at onset in 55% of the seizures. Seizure onsets with clonic, tonic and hypomotor features were seen in 20%, 8% and 18% respectively. Clinico-electrical correlations were as follows. The EEG discharge involved both hemispheres in 54% of all seizures, in clonic seizures this was 93%. Focal clonic seizures were associated with EEG seizure onset from the contralateral hemisphere. Majority of the clonic and hypomotor seizures had a left hemisphere ictal EEG onset. Orolingual seizures frequently started from the right hemisphere, whereas ocular and autonomic seizures arose from either hemisphere. There was no significant difference in mortality, morbidity, abnormal neuroimaging and EEG background abnormalities in babies with or without clonic seizures. This study provides insights into neuronal networks that underpin electroclinical seizures, by analysing and classifying the obvious initial clinical features and those during the seizure.
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A Granger causality measure for point process models of ensemble neural spiking activity.
PLoS Comput. Biol.
PUBLISHED: 02-17-2011
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The ability to identify directional interactions that occur among multiple neurons in the brain is crucial to an understanding of how groups of neurons cooperate in order to generate specific brain functions. However, an optimal method of assessing these interactions has not been established. Granger causality has proven to be an effective method for the analysis of the directional interactions between multiple sets of continuous-valued data, but cannot be applied to neural spike train recordings due to their discrete nature. This paper proposes a point process framework that enables Granger causality to be applied to point process data such as neural spike trains. The proposed framework uses the point process likelihood function to relate a neurons spiking probability to possible covariates, such as its own spiking history and the concurrent activity of simultaneously recorded neurons. Granger causality is assessed based on the relative reduction of the point process likelihood of one neuron obtained excluding one of its covariates compared to the likelihood obtained using all of its covariates. The method was tested on simulated data, and then applied to neural activity recorded from the primary motor cortex (MI) of a Felis catus subject. The interactions present in the simulated data were predicted with a high degree of accuracy, and when applied to the real neural data, the proposed method identified causal relationships between many of the recorded neurons. This paper proposes a novel method that successfully applies Granger causality to point process data, and has the potential to provide unique physiological insights when applied to neural spike trains.
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Motor cortical networks for skilled movements have dynamic properties that are related to accurate reaching.
Neural Plast.
PUBLISHED: 02-15-2011
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Neurons in the Primary Motor Cortex (MI) are known to form functional ensembles with one another in order to produce voluntary movement. Neural network changes during skill learning are thought to be involved in improved fluency and accuracy of motor tasks. Unforced errors during skilled tasks provide an avenue to study network connections related to motor learning. In order to investigate network activity in MI, microwires were implanted in the MI of cats trained to perform a reaching task. Spike trains from eight groups of simultaneously recorded cells (95 neurons in total) were acquired. A point process generalized linear model (GLM) was developed to assess simultaneously recorded cells for functional connectivity during reaching attempts where unforced errors or no errors were made. Whilst the same groups of neurons were often functionally connected regardless of trial success, functional connectivity between neurons was significantly different at fine time scales when the outcome of task performance changed. Furthermore, connections were shown to be significantly more robust across multiple latencies during successful trials of task performance. The results of this study indicate that reach-related neurons in MI form dynamic spiking dependencies whose temporal features are highly sensitive to unforced movement errors.
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Fast activity during EEG seizures in neonates.
Epilepsy Res.
PUBLISHED: 02-06-2011
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Paroxysmal fast activity (FA) has been proposed as a marker for epileptic networks. We explore the presence and significance of ictal FA on scalp video EEG seizures (EEG Sz) recorded in neonates.
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Ictal electroencephalograms in neonatal seizures: characteristics and associations.
Pediatr. Neurol.
PUBLISHED: 01-17-2011
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The characteristics of ictal electroencephalograms in 160 neonatal seizures of 43 babies were correlated with mortality and neurodevelopmental outcomes. Neonatal seizures are focal at onset, most frequently temporal, and often occur during sleep. Twenty-one percent of babies with seizures died, and 76% of survivors manifested neurodevelopmental impairment during 2-6-year follow-up. A low-amplitude ictal electroencephalogram discharge was associated with increased mortality, and a frequency of <2 Hz with increased morbidity. Status epilepticus, ictal fractions, multiple foci, and bihemispheric involvement did not influence outcomes. Of 160 seizures, 99 exhibited no associated clinical features (electrographic seizures). Neonatal seizures with clinical correlates (electroclinical seizures) exhibited a higher amplitude and frequency of ictal electroencephalogram discharge than electrographic seizures. During electroclinical seizures, the ictal electroencephalogram was more likely to involve larger areas of the brain and to cross the midline. Mortality and morbidity were similar in babies with electroclinical and electrographic seizures, emphasizing the need to diagnose and treat both types. Ictal electroencephalogram topography has implications for electrode application during limited-channel, amplitude-integrated electroencephalograms. We recommend temporal and paracentral electrodes. Video electroencephalograms are important in diagnosing neonatal seizures and providing useful information regarding ictal electroencephalogram characteristics.
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Unlicensed applications of licensed psychotropic drugs in an intellectual disability clinical service: retrospective case-note study.
J Intellect Disabil
PUBLISHED: 11-11-2010
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Prescribing of psychotropic drugs for unlicensed indications is common in inpatients with intellectual disability, but the frequency in the community is uncertain. This study examined the medical records of all patients undergoing review within a single service led by a consultant psychiatrist. The notes of 114 individuals with varying degrees of disability and independence were available. In 78 percent of individuals the cause of disability was uncertain; 72, 69 and 78 percent had mental health problems, physical ill-health and behavioural challenges respectively; and 66 percent received licensed drugs for unlicensed applications, principally for aggression, risperidone being the drug most prescribed. There were no significant differences between groups with mild, moderate or severe disability in the proportion receiving licensed and unlicensed prescriptions. Unlicensed prescribing was similarly common for patients living in different settings. Prescribing for unlicensed applications in patients with intellectual disability is common, regardless of degree of disability or place of residence.
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Statistical inference for assessing functional connectivity of neuronal ensembles with sparse spiking data.
IEEE Trans Neural Syst Rehabil Eng
PUBLISHED: 10-11-2010
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The ability to accurately infer functional connectivity between ensemble neurons using experimentally acquired spike train data is currently an important research objective in computational neuroscience. Point process generalized linear models and maximum likelihood estimation have been proposed as effective methods for the identification of spiking dependency between neurons. However, unfavorable experimental conditions occasionally results in insufficient data collection due to factors such as low neuronal firing rates or brief recording periods, and in these cases, the standard maximum likelihood estimate becomes unreliable. The present studies compares the performance of different statistical inference procedures when applied to the estimation of functional connectivity in neuronal assemblies with sparse spiking data. Four inference methods were compared: maximum likelihood estimation, penalized maximum likelihood estimation, using either l(2) or l(1) regularization, and hierarchical Bayesian estimation based on a variational Bayes algorithm. Algorithmic performances were compared using well-established goodness-of-fit measures in benchmark simulation studies, and the hierarchical Bayesian approach performed favorably when compared with the other algorithms, and this approach was then successfully applied to real spiking data recorded from the cat motor cortex. The identification of spiking dependencies in physiologically acquired data was encouraging, since their sparse nature would have previously precluded them from successful analysis using traditional methods.
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Differential involvement of excitatory and inhibitory neurons of cat motor cortex in coincident spike activity related to behavioral context.
J. Neurosci.
PUBLISHED: 06-11-2010
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To assess temporal associations in spike activity between pairs of neurons in the primary motor cortex (MI) related to different behaviors, we compared the incidence of coincident spiking activity of task-related (TR) and non-task-related (NTR) neurons during a skilled motor task and sitting quietly in adult cats (Felis domestica). Chronically implanted microwires were used to record spike activity of MI neurons in four animals (two male and two female) trained to perform a skilled reaching task or sit quietly. Neurons were identified as TR if spike activity was modulated during the task (and NTR if not). Based on spike characteristics, they were also classified as either regular-spiking (RS, putatively excitatory) or fast-spiking (FS, putatively inhibitory) neurons. Temporal associations in the activities of simultaneously recorded neurons were evaluated using shuffle-corrected cross-correlograms. Pairs of NTR and TR neurons showed associations in their firing patterns over wide areas of MI (representing forelimb and hindlimb movements) during quiet sitting, more commonly involving RS neurons. During skilled task performance, however, significantly coincident firing was seen almost exclusively between TR neurons in a smaller part of MI (representing forelimb movements), involving mainly FS neurons. The findings of this study show evidence for widespread interactions in MI when the animal sits quietly, which changes to a more specific and restricted pattern of interactions during task performance. Different populations of excitatory and inhibitory neurons appear to be synchronized during skilled movement and quiet sitting.
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Schizophrenia and borderline personality disorder: similarities and differences in the experience of auditory hallucinations, paranoia, and childhood trauma.
J. Nerv. Ment. Dis.
PUBLISHED: 06-10-2010
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This study investigated similarities and differences in the experience of auditory hallucinations, paranoia, and childhood trauma in schizophrenia and borderline personality disorder (BPD). Patients with clinical diagnoses of schizophrenia or BPD were interviewed using the Structured Clinical Interviews for DSM-IV. Axes 1 and 2 and auditory hallucinations, paranoia, and childhood trauma were assessed. A total of 111 patients participated; 59 met criteria for schizophrenia, 33 for BPD, and 19 for both. The groups were similar in their experiences of voices, including the perceived location of them, but they differed in frequency of paranoid delusions. Those with a diagnosis of BPD, including those with schizophrenia comorbidity, reported more childhood trauma, especially emotional abuse. BPD and schizophrenia frequently coexist, and this comorbidity has implications for diagnostic classification and treatment. Levels of reported childhood trauma are especially high in those with a BPD diagnosis, whether they have schizophrenia or not, and this requires assessment and appropriate management.
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Paradoxical role of prion protein aggregates in redox-iron induced toxicity.
PLoS ONE
PUBLISHED: 03-29-2010
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Imbalance of iron homeostasis has been reported in sporadic Creutzfeldt-Jakob-disease (sCJD) affected human and scrapie infected animal brains, but the contribution of this phenotype to disease associated neurotoxicity is unclear.
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Level of purposeful hand function as a marker of clinical severity in Rett syndrome.
Dev Med Child Neurol
PUBLISHED: 03-19-2010
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We investigated relationships between hand function and genotype and aspects of phenotype in Rett syndrome.
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Neurodevelopmental outcomes in neonates with seizures: a numerical score of background encephalography to help prognosticate.
J. Child Neurol.
PUBLISHED: 03-11-2010
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There is a high incidence of mortality and neurodevelopmental sequelae in babies with neonatal seizures. The electroencephalography (EEG) background has been shown to be an excellent predictor of outcome by most studies, with a few suggesting limited value in prognostication. Previous studies suggest poor prognosis with severely abnormal backgrounds, but prediction was difficult with moderate abnormalities. The proposed numerical scoring system for the EEG background provides an objective method of evaluation with improved reproducibility, categorization, and prognostication. Our study showed that the numerical score of EEG background was a good predictor of outcome. Higher numerical scores reflecting greater abnormality of background EEG were associated with increasing incidence of mortality, neurodevelopmental impairment, cerebral palsy, vision and hearing impairment, and epilepsy. The numerical score also correlated with neuroimaging abnormalities. A numerical EEG score can help target interventional strategies for neonatal seizures.
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Neural integration of reaching and posture: interhemispheric spike correlations in cat motor cortex.
Exp Brain Res
PUBLISHED: 01-26-2010
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To study the interlimb coordination of reaching and postural movements, chronically implanted microelectrodes were used to record single unit activity from the primary motor cortex (MI) of cats during performance of a trained reaching task. Recordings were made from both cerebral hemispheres to record neurons that modulated their activity during reaching (reach-related neurons) and supportive (posture-related neurons) movements of either forelimb. Evidence of temporal associations in the activities of simultaneously recorded reach- and posture-related neurons was evaluated using shuffle-corrected cross correlograms. The spike activity of approximately 34% of reach-related neurons was temporally correlated with the spike activity of simultaneously recorded posture-related neurons in the opposite motor cortex. Significant associations in the spike activity of neurons recorded from homotopic representational areas of the motor cortex in opposite hemispheres have not previously been reported. These interactions may have an important role in the coordination of opposite forelimbs during reaching movements and postural actions.
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A regularized point process generalized linear model for assessing the functional connectivity in the cat motor cortex.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 12-08-2009
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Identification of multiple simultaneously recorded neural spike train recordings is an important task in understanding neuronal dependency, functional connectivity, and temporal causality in neural systems. An assessment of the functional connectivity in a group of ensemble cells was performed using a regularized point process generalized linear model (GLM) that incorporates temporal smoothness or contiguity of the solution. An efficient convex optimization algorithm was then developed for the regularized solution. The point process model was applied to an ensemble of neurons recorded from the cat motor cortex during a skilled reaching task. The implications of this analysis to the coding of skilled movement in primary motor cortex is discussed.
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Patterns of spatio-temporal correlations in the neural activity of the cat motor cortex during trained forelimb movements.
Somatosens Mot Res
PUBLISHED: 08-22-2009
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In order to study how neurons in the primary motor cortex (MI) are dynamically linked together during skilled movement, we recorded simultaneously from many cortical neurons in cats trained to perform a reaching and retrieval task using their forelimbs. Analysis of task-related spike activity in the MI of the hemisphere contralateral to the reaching forelimb (in identified forelimb or hindlimb representations) recorded through chronically implanted microwires, was followed by pairwise evaluation of temporally correlated activity in these neurons during task performance using shuffle corrected cross-correlograms. Over many months of recording, a variety of task-related modulations of neural activities were observed in individual efferent zones. Positively correlated activity (mainly narrow peaks at zero or short latencies) was seen during task performance frequently between neurons recorded within the forelimb representation of MI, rarely within the hindlimb area of MI, and never between forelimb and hindlimb areas. Correlated activity was frequently observed between neurons with different patterns of task-related activity or preferential activity during different task elements (reaching, feeding, etc.), and located in efferent zones with dissimilar representation as defined by intracortical microstimulation. The observed synchronization of action potentials among selected but functionally varied groups of MI neurons possibly reflects dynamic recruitment of network connections between efferent zones during skilled movement.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.