Relevant bibliographies by topics / Extracellular recording / Dissertations / Theses
To see the other types of publications on this topic, follow the link: Extracellular recording.

Dissertations / Theses on the topic 'Extracellular recording'

Author: Grafiati
Published: 4 June 2021
Last updated: 10 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 39 dissertations / theses for your research on the topic 'Extracellular recording.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Blum, Richard Alan. "An Electronic System for Extracellular Neural Stimulation and Recording." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16192.

Full text
Abstract:
A system for extracellular neural interfacing that had the capability for stimulation and recording at multiple electrodes was presented. As the core of this system was a custom integrated circuit (IC) that contained low-noise amplifiers, stimulation buffers, and artifact-elimination circuitry. The artifact-elimination circuitry was necessary to prevent the activity of the stimulation buffers from interfering with the normal functioning of the low-noise amplifiers. The integrated circuits were fabricated in in a 0.35 micron CMOS process. We measured input-referred noise levels for the amplifiers as low as 3.50 microvolts (rms) in the in the bandwidth 30 Hz-3 kHz, corresponding to the frequency range of neural action potentials. The power consumption was 120 microwatts, corresponding to a noise-efficiency factor of 14.5. It was possible to resume recording signals within 2 ms of a stimulation, using the same electrode for both stimulation and recording. A filtering algorithm to remove the post-discharge artifact was also presented. The filtering was implemented using a field-programmable gate array (FPGA). The filtering algorithm itself consisted of blanking for the duration of the stimulation and artifact-elimination, followed by a wavelet de-noising. The wavelet de-noising split the signal into frequency ranges, discarded those ranges that did not correspond to neural signals, applied a threshold to the retained signals, and recombined the different frequency ranges into a single signal. The combination of the filtering with the artifact-elimination IC resulted in the capability for artifact-free recordings.
APA, Harvard, Vancouver, ISO, and other styles
2

Bernstein, Jacob (Jacob Gold). "Development of extracellular electrophysiology methods for scalable neural recording." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107581.

Full text
Abstract:
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references.
In order to map the dynamics of neural circuits in mammalian brains, there is a need for tools that can record activity over large volumes of tissue and correctly attribute the recorded signals to the individual neurons that generated them. High-resolution neural activity maps will be critical for the discovery of new principles of neural coding and neural computation, and to test computational models of neural circuits. Extracellular electrophysiology is a neural recording method that has been developed to record from large populations of neurons, but well-known problems with signal attribution pose an existential threat to the viability of further system scaling, as analyses of network function become more sensitive to errors in attribution. A key insight is that blind-source separation algorithms such as Independent Component Analysis may ameliorate problems with signal attribution. These algorithms require recording signals at much finer spatial resolutions than existing probes have accomplished, which places demands on recording system bandwidth. We present several advances to technologies in neural recording systems, and a complete neural recording system designed to investigate the challenges of scaling electrophysiology to whole brain recording. We have developed close-packed microelectrode arrays with the highest density of recording sites yet achieved, for which we built our own data acquisition hardware, developed with a computational architecture specifically designed to scale to over several orders of magnitude. We also present results from validation experiments using colocalized patch clamp recording to obtain ground-truth activity data. This dataset provides immediate insight into the nature of electrophysiological signals and the interpretation of data collected from any electrophysiology recording system. This data is also essential in order to optimize probe development and data analysis algorithms which will one day enable whole-brain activity mapping.
by Jacob G. Bernstein.
Ph. D.
APA, Harvard, Vancouver, ISO, and other styles
3

Sayed, Herbawi Abdalrahman [Verfasser], and Oliver [Akademischer Betreuer] Paul. "High-density CMOS probes for large-scale extracellular neural recording." Freiburg : Universität, 2020. http://d-nb.info/1226657265/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kuykendal, Michelle Lea. "Closed-loop optimization of extracellular electrical stimulation for targeted neuronal activation." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52303.

Full text
Abstract:
We have developed a high-throughput system of closed-loop electrical stimulation and optical recording that facilitates the rapid characterization of extracellular stimulus-evoked neural activity. The ability to selectively stimulate a neuron is a defining characteristic of next-generation neural prostheses. Greater stimulus control and differential activation of specific neuronal populations allows for prostheses that better mimic their biological counterparts. In our system, we deliver square current pulses using a microelectrode array; automated real-time image processing of high-speed digital video identifies the neuronal response; and a feedback controller alters the applied stimulus to achieve a targeted response. The system controller performs directed searches within the strength-duration (SD) stimulus parameter space to build probabilistic neuronal activation curves. An important feature of this closed-loop system is a reduction in the number of stimuli needed to derive the activation curves when compared to the more commonly used open-loop system: this allows the closed-loop system to spend more time probing stimulus regions of interest in the multi-parameter waveform space, facilitating high resolution analysis. The stimulus-evoked activation data were well-fit to a sigmoid model in both the stimulus strength (current) and duration (pulse width) slices through the waveform space. The 2-D analysis produced a set of probability isoclines corresponding to each neuron-electrode pairing, which were fit to the SD threshold model described by Lapique (1907). We show that stimulus selectivity within a given neuron pair is possible in the one-parameter search space by using multiple stimulation electrodes. Additionally, by applying simultaneous stimuli to adjacent electrodes, the interaction between stimuli alters the neuronal activation threshold. The interaction between simultaneous multi-electrode multi-parameter stimulus waveforms creates an opportunity for increased stimulus selectivity within a population. We demonstrated that closed-loop imaging and micro-stimulation technology enable the study of neuronal excitation across a large parameter space, which is requisite for controlling neuronal activation in next generation clinical solutions.
APA, Harvard, Vancouver, ISO, and other styles
5

Czeschik, Anna [Verfasser], Bernhard [Akademischer Betreuer] Wolfrum, and Jörg [Akademischer Betreuer] Fitter. "Nanocavity arrays for extracellular recording and stimulation of electroactive cell systems / Anna Czeschik ; Bernhard Wolfrum, Jörg Fitter." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130151530/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Patel, Manoj Kumar. "An investigation into electrophysiological changes associated with myocardial ischaemia and reperfusion using extracellular and intracellular recording techniques." Thesis, Coventry University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308953.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Sörensen, Sören Per. "Development of a cell-based drug screening platform : extracellular recording and electrochemical impedance spectroscopy on microelectrode array chips." Thesis, University of Bath, 2007. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486476.

Full text
Abstract:
Two established methods, Electrochemical Impedance Spectroscopy (EIS) and extracellular recording, were implemented into a technology platform for non-invasive whole-cell biosensing. Electrical activity of cardiomyocytes and cell-substrate interaction of human ovarian cancer cells was monitored on electrode array chips. The performance of cells inside a microfluidic or closed low volume environment was investigated. Prior to the development of the entire microfluidic platform the two transducing methods were evaluated in single experiments. Processes as cellular attachment and detachment were monitored using EIS and single frequency impedance sensing. Electrodes of different size and structure were employed and compared for their impedance response. It was shown that small electrodes (A = 9·10-6 cm²) are more sensitive to cell-substrate interaction than larger ones (A = 9·10-5 cm²) and that the frequency used for analysis has a profound influence on the sensitivity. Data were modelled using a common equivalent circuit that represents a cell layer on an electrode resulting in an increase of the impedance magnitude by <170 % due to cell attachment. In order to demonstrate the potential of this method for biomedical applications, experiments related to anti-cancer strategies were performed. Cell detachment was induced by addition of synthetic integrin ligands and by hypericin mediated photodynamic therapy and monitored with impedance-based biosensing. Electrical activity of cardiomyocytes cultured on microelectrode arrays was monitored inside a microfluidic system. The chronotropic drug isoproterenol was applied using a robotic dispensing machine, and the resulting changes in spike rate and duration were compared with results gained by experiments with a large scale MEA chip. The experimental findings inspired the development of a technology platform that was finally evaluated by monitoring extracellular signals from myocytes in response to Isoproterenol. Another topic was the comparison of cell-substrate interaction monitored on various electrode structures.
APA, Harvard, Vancouver, ISO, and other styles
8

Bradley, Peter Mark James. "A Novel Fibre-Optic Probe for Simultaneous Extracellular Electrical and Intracellular Fluorescence Recording in Neurones In Situ and In Vito." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503894.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Steidl, Esther. "Mise au point d’une plateforme de tests in vitro pour l’évaluation du potentiel proconvulsivant de façon précoce au cours du développement de médicaments." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0050.

Full text
Abstract:
L’objectif des travaux de recherche présentés ici était la mise au point d’une plateforme de tests pour identifier le potentiel proconvulsivant de composés de façon précoce au cours de leur développement. Ces tests ont été réalisés in vitro à partir de tranches d’hippocampes enregistrées à l’aide de multi-electrode arrays (MEA). La technique du MEA est particulièrement adaptée pour ce type d’investigations car elle permet d’évaluer l’effet de composés sur une large partie d’un réseau neuronal natif. De plus, cette technique permet de réaliser des tests à moyen débit et à partir de faibles quantités de composé.Tout d’abord, l’évaluation de composés de référence a permis de déterminer les paramètres d’intérêt, qui sont modifiés par des composés proconvulsivants. Les composés proconvulsivants testés ont causé une augmentation de l’aire des potentiels d’action de population et l’apparition de potentiels d’action additionnels, déclenché des décharges épileptiformes et/ou augmenté la fréquence de décharge des neurones de la région CA1. Les conditions expérimentales des tests réalisés ont ensuite été modifiées pour augmenter leur sensibilité et permettre la détection de proconvulsivants faibles. Cette plateforme de 3 tests complémentaires a été nommée NS-PC set. Pour valider la plateforme NS-PC set, 15 composés fournis par des sociétés pharmaceutiques partenaires, incluant des contrôles positifs et négatifs, ont été testés à l’aveugle. Un nouveau type de test plus rapide et abordable appelé NS-PC screen a ensuite été mis au point, sur la base d’enregistrement de décharges épileptiformes induites par la 4-aminopyridine dans des tranches d’hippocampe
The goal of the present work was to develop a platform of tests that could predict the proconvulsive potential of compounds in development as early as possible during preclinical phases. These tests were carried out in vitro from hippocampal slices recorded with multi-electrode arrays (MEAs). The MEA technology is particularly adapted because it allows to investigate compounds’ effect on a wide area of a native neural network, including all the complexity and organization of the different cell types. In addition, rapidity and low compound consumption of the MEA-based assays make them suitable for early stages of development.First, the evaluation of reference proconvulsive/seizurogenic compounds allowed to determine the parameters that should be monitored to detect proconvulsive properties. It appeared that reference compounds triggered one or several of the following effects: increase of the population spikes area and repetition of spikes, triggering of epileptiform discharges and/or increase of the CA1 neurons firing. The experimental conditions of the assays were then modified to increase their sensitivity and thus detect even weak proconvulsive compounds. This platform of 3 complementary assays was termed NS-PC set.15 compounds, including positive and negative controls, were provided by partner pharmaceutical companies to be tested under blind conditions on NS-PC set. A new faster and cheaper assay, termed NS-PC screen, was also designed based on the recording of 4-aminopyridine-induced epileptiform discharges in hippocampal slices
APA, Harvard, Vancouver, ISO, and other styles
10

Krüger, Hagen. "Elektrophysiologische Untersuchungen zu Einflüssen von ionotropen Glutamatantagonisten sowie 5-HT1A-Agonisten auf die Kaliumchlorid-induzierte "spreading depression" im neokortikalen Hirnschnittpräparat der adulten Ratte." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2000. http://dx.doi.org/10.18452/14462.

Full text
Abstract:
Die kortikale spreading depression (SD), wie sie von Leão 1944 zuerst beschrieben wurde, ist ein elektrophysiologisches Phänomen, das in der Pathophysiologie der Aurasymptomatik einer Mi-gräneattacke und Ischämie-induzierter Zellschäden diskutiert wird. Während der akuten fokalen zerebralen Ischämie treten eine Reihe von Ereignissen wie eine massive Entzündungsreaktion und die allmähliche Einbeziehung einer zunächst viablen ischämischen Randzone - der Penum-bra - in das infarzierte Hirngewebe auf. Da an diesen Ereignissen SD-ähnliche Depolarisationen kausal beteiligt sind, ist die pharmakologische Verringerung von SD-Episoden bzw. eine Ver-kleinerung ihrer Amplitude und Dauer unter in vitro als auch tierexperimentellen in vivo Bedin-gungen eine mögliche neuroprotektive Strategie. In der vorliegenden Arbeit wurde ein in vitro Modell beschrieben, das am Hirnschnittpräparat des Neokortex der adulten Ratte eine reproduzierbare Auslösung von SD-Wellen unter normoxi-schen Bedingungen gestattet. Anhand von charakteristischen elektrophysiologischen Parametern einer SD wie Amplitude, Dauer und Ausbreitungsgeschwindigkeit wurden die gute Überein-stimmungen dieses in vitro Modells mit in vivo Modellen gezeigt. Obwohl SD Wellen am nicht-ischämischen Kortex keine morphologischen Schäden verursachen, zeigte sich in den hier vorge-stellten Experimenten eine funktionelle Unterdrückung der GABAergen hemmenden Mechanis-men des Neokortex nach repetitiven SDs auch bei ausreichender Energie- und Sauerstoffversor-gung. Die hier diskutierten Ergebnisse demonstrierten, daß unter in vitro Bedingungen der AMPA-Glutamatrezeptor für die Auslösung und Ausbreitung einer SD eine untergeordnete Rolle spielt. Demgegenüber erwies sich die NMDA-Rezeptoraktivierung als herausragend für eine SD, da die Blockade dieses Rezeptors mit dem nicht-kompetitiven Antagonisten Ketamin die SD-Amplitude und SD-Dauer signifikant verringerte. Die Anwendung der selektiven 5-HT1A-Agonisten 8-OH-DPAT und BAY x 3702 erwies sich als eine neue Möglichkeit, die Zeitdauer einer SD zu verringern. Die aufgezeigte SD-induzierte neuronale Hyperexzitabilität kann unter normoxischen Bedingun-gen zelluläre Dysfunktionen verursachen und auch an einer Generierung der Aura eines Migrä-neanfalls beteiligt sein. Unter hypoxisch-ischämischen Bedingungen könnte eine SD-induzierte Dysfunktion GABAerger Kontrollmechanismen die Ausweitung ischämischer Zellschäden be-wirken. Die Hoffnungen auf eine effektive Schlaganfalltherapie haben sich mit den bisherigen NMDA-Antagonisten trotz ihrer hier bestätigten guten in vitro Wirksamkeit aufgrund der Interferenz mit physiologischen Glutamatfunktionen im Kortex nicht erfüllt. Die hier gezeigte konzentrationsab-hängige Verkürzung der SD-Dauer durch die Aktivierung des 5-HT1A-Serotoninrezeptors unter in vitro Bedingungen kann bei der bekannten hohen 5-HT1A-Rezeptor-mRNA-dichte an beson-ders ischämievulnerablen Neuronen einen neuen neuroprotektiven Ansatz auch beim Menschen darstellen. Weitere Untersuchungen müssen zeigen, ob die hier beschriebene enge Verflechtung des serotonergen Systems mit der glutamatergen Neurotransmission eventuell auch zu uner-wünschte Wirkungen unter in vivo Bedingungen führt.
Repetitive cortical spreading depression (SD) and SD-like events, associated with a massive de-polarization of neuronal and glial cells, is thought to play a key role in the induction of neuronal damage in the peri-infarct zone following experimental focal cerebral ischemia. In addition, ex-perimental and clinical data suggest that SD is the underlying mechanism of neurological distur-bances during migraine auras as well. However, detailed analyses on the consequences of repeti-tive SDs on cortical function and involved receptors are lacking. Using an in vitro rat model of SD I investigated in this thesis the electrophysiological properties of repetitive potassium chloride (KCl)-induced SDs, their influence on synaptic neurotransmis-sion and the effects of ionotropic glutamate antagonists and 5-HT1A agonists in neocortical slices obtained from adult rats. Whereas repetitive SDs revealed only non-significant variations in du-ration, amplitude and integral when elicited at intervals of 30 min, paired-pulse inhibition of ex-tracellularly recorded field potential responses was significantly affected by repetitive SD even under normoxic conditions. Compared to the control recordings, each SD episode caused a sig-nificant decrease in the efficacy of intracortical GABAergic inhibition by approximately 10%. Since excitatory synaptic transmission was unaffected, these data indicate that repetitive SDs cause a selective suppression of GABAergic function even in the non-ischemic brain. None of the compounds tested prevented the SD-induced cortical disinhibition. However, the SD-associated negative shift in the extracellular DC potential was reduced by ketamine, a selective N-methyl-D-aspartic acid (NMDA-) receptor antagonist. Ketamine significantly (p < 0.01) re-duced the amplitude of the first SD peak and blocked the second SD peak. Ketamine also de-creased the SD duration at half maximal amplitude (p < 0.05). NBQX, a selective a-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist did not affect the SD-accompanied cortical depolarization, whereas selective 5-hydroxytryptamine (5-HT)1A receptor agonists 8-OH-DPAT and BAY x 3702 shortened concentration-dependently the duration of the SD up to 50 %. Nevertheless, both 5-HT1A receptor agonists caused a strong disinhibition of neu-ronal function with a tendency towards paired-pulse facilitation as well. Thus, repetitive SD and SD-like events may induce neuronal hyperexcitability due to a selective suppression of intrinsic inhibitory GABAergic function. Under normoxic conditions, SD-induced disinhibition may be involved in the generation and maintenance of migraine or associated neurological disturbances. Under hypoxic-ischemic conditions, neuronal hyperexcitability may contribute to the gradual expansion of the ischemic core and the metabolic deterioration of the penumbral tissue after SD episodes. This underlines the deleterious effect of SD to the outcome of focal cerebral ischemia. Although the precise mecha-nisms of SD generation and propagation remains far from established, the present pharmacologi-cal profile of KCl-induced SD in vitro links the induction and propagation of SD in rat neocorti-cal slices mainly to a local increase of [K + ] e and a subsequent activation of NMDA- receptors. This corroborates the neuroprotective effect of a NMDA- receptor blockade observed in various in vitro and in vivo models. However, as it has been demonstrated in clinical trials, NMDA- re-ceptor antagonists in use today cause psychomimetic and cardiovascular side effects in humans and are therefore currently of low clinical benefit. The activation of 5-HT1A receptors by selective agonists represents a new pharmacological strategy in the treatment of acute ischemic stroke, since shortened SD waves may represent a less energy-consuming process under conditions of limited energy supply and are probably associated with an efflux of excitatory neurotransmitters to a lesser extent. The potential clinical benefit of 5-HT 1A receptor agonists remains to be investi-gated in clinical trials, since systemic administration of these compounds after the onset of acute focal cerebral ischemia might interfere with normal functions of glutamatergic neurotransmission in the intact, non-ischemic brain.
APA, Harvard, Vancouver, ISO, and other styles
11

Kobaïter, Maarawi Sandra. "Effets électrophysiologiques de la stimulation du cortex moteur sur les noyaux somatosensorielslatéraux du thalamus : étude expérimentale sur un modèle de stimulation du cortex moteur chez le chat." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10100/document.

Full text
Abstract:
La stimulation du cortex moteur (SCM) est une technique neurochirurgicale utilisée chez l'Homme comme traitement de dernier recours pour les douleurs neuropathiques rebelles. Elle a été développée sur des bases empiriques. Ce travail vise à une meilleure compréhension des mécanismes d'action de la SCM qui restent incomplètement élucidés à ce jour. L'objectif de cette thèse est d'étudier les effets électrophysiologiques de la SCM au niveau thalamique, chez un modèle de chat. La première partie de cette étude a consisté à établir une cartographie stéréotaxique du cortex moteur (CM) de cet animal, inexistante dans la littérature. À partir de cette cartographie, nous avons pu établir et valider un modèle de SCM chez cet animal, implanté de façon mini-invasive. La deuxième partie de ce travail a consisté à recueillir et analyser les changements électrophysiologiques de l'activité extracellulaire unitaire des cellules du noyau ventro-postéro-latéral (VPL) du thalamus, induits par différents protocoles de SCM. Nos résultats montrent une modulation de l'activité des cellules du VPL par la SCM, qui varie en fonction de la nature nociceptive ou non de la cellule thalamique. La SCM augmente l'activité des cellules non nociceptives et diminue celle des cellules nociceptives. Pour une cellule donnée, l'effet observé est indépendant de la correspondance somatotopique entre la région du CM stimulée et la localisation sur le corps du champ récepteur de la cellule enregistrée. Ce travail a ainsi permis de montrer l'existence d'une neuro-modulation différentielle du VPL par la SCM en fonction de la nature de la cellule thalamique
Motor cortex stimulation (MCS) is a neurosurgical technique developed on empirical basis and currently used as last solution for patients suffering from refractory neuropathic pain. The present work is a new attempt among other contemporary studies aiming to understand the mechanisms of action of MCS, which remain incompletely elucidated at that time. The main objective of this thesis is to study the electrophysiological effect of MCS at the thalamic level, in a cat model. The first part of this work aims to establish the stereotactic somatotopic map of the cat motor cortex (MC), not available so far in the literature. Based on this mapping, we created and validated a cat model of MCS, using a mini-invasive electrode implantation. The second part of this study included a recording and analysis of the potential changes of the unitary extracellular activity of cells located in the thalamic ventro-postero-lateral (VPL) nucleus, induced by different MCS protocols. Our results indicate a modulation of the VPL cells activity after MCS, depending on the nociceptive or non-nociceptive nature of the recorded thalamic cell. MCS increases the activity of non-nociceptive cells and decreases that of nociceptive cells. For a given cell the matching between the somatotopy of the MC stimulated region and the receptive field localization of the recorded thalamic cell is not a prerequisite for obtaining such a modulation. In conclusion, the present work has proven a neuro-modulatory differential effect of MCS on nociceptive and non-nociceptive cells in the thalamic VPL nucleus
APA, Harvard, Vancouver, ISO, and other styles
12

Franke, Felix [Verfasser], and Klaus [Akademischer Betreuer] Obermayer. "Real-Time Analysis of Extracellular Multielectrode Recordings / Felix Franke. Betreuer: Klaus Obermayer." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2012. http://d-nb.info/1018985247/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Natora, Michal [Verfasser], and Klaus [Akademischer Betreuer] Obermayer. "Adaptive and Blind Array Processing Techniques for Extracellular Electrode Recordings / Michal Natora. Betreuer: Klaus Obermayer." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/1014619645/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Erlandson, Melissa. "Investigating the plasticity of sensory cortical circuits in the context of learning in the wild-type mouse and a conditional mouse model of fragile X syndrome." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0342.

Full text
Abstract:
L'objectif de ce projet est l’étude de la plasticité des circuits corticaux dans le contexte de l'apprentissage des souris « sauvages » et modèles du syndrome de l’X fragile. Des études sur l'efficacité de la combinaison d'enregistrement des potentiels de champ locaux extracellulaires avec la stimulation laser UV (LSPS) pour cartographier les réseaux ont été réalisées. Nous avons trouvé des enregistrements de champs extracellulaires qui pourraient être utilisés pour détecter les réponses synaptiques évoquées par LSPS. Nos résultats indiquent une méthode alternative pour obtenir des cartes complètes de réseaux intracorticaux excitateurs. Ensuite, nous avons développé un paradigme d'apprentissage associatif sensoriel et étudié ses effets sur les réseaux intracorticaux excitateurs du cortex baril. Ex vivo un affaiblissement des projections excitatrices entre les couches 4 et 2/3 qui dans les colonnes de vibrisses C a été observée. Enfin, nous avons utilisé ces mêmes approches dans une souris modèle du syndrome de l'X fragile (FXS). Pour étudier les liens entre les déficits sensoriels, l'apprentissage associatif et les altérations fonctionnelles des réseaux sensoriels, nous avons utilisé un modèle de souris mutantes dans lequel la pathologie FXS était ciblée sur la couche 4 du cortex somatosensoriel. Il a été constaté que les souris WT présentaient une dépression similaire, alors qu'elle était absente FXS. En conclusion, les études sur les mutants sensoriels de type sauvage ont mis en lumière les conséquences de l'apprentissage sur les réseaux corticaux sensoriels et les liens entre la plasticité des réseaux corticaux sensoriels et les capacités cognitives
The aim of this project is to study the plasticity of the cortical circuits in the context of the learning of wild type mice and models of Fragile X Syndrome. First, investigations into the efficacy of recording combination of extracellular local field potentials with UV laser stimulation (LSPS) to map networks were performed. We found extracellular field records could be used to detect the synaptic responses evoked by LSPS. Our results indicate an alternative method for obtaining complete maps of excitatory intracortical networks. Next, we developed a sensory associative learning paradigm and studied its effects on excitatory intracortical networks the barrel cortex. Ex vivo a weakening of the excitatory projections between layers 4 and 2/3 which in the columns of vibrissae C was observed and declined function of the speed of the behavioural response. Finally, we used these same approaches in a Fragile X Syndrome (FXS) model mouse. To study the links between sensory deficits, associative learning, and functional alterations of sensory networks, we used a model of mutant mice in which the FXS pathology was targeted to the layer 4 of the somatosensory cortex. Our hypotheses were that behavioural conditioning would change the cortical sensory circuits of the FXS sensory mutant and that the abnormal plasticity of these circuits would in turn affect the performance. It was found the WT mice exhibited a similar depression, whereas it was absent FXS. In conclusion, wild type mouse and FXS sensory mutant studies shed light on the consequences of learning on sensory cortical networks and on the links between plasticity of sensory cortical networks and cognitive abilities
APA, Harvard, Vancouver, ISO, and other styles
15

Tomsett, Richard John. "A novel simulation framework for modelling extracellular recordings in cortical tissue : implementation, validation and application to gamma oscillations in mammals." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2436.

Full text
Abstract:
This thesis concerns the simulation of local field potentials (LFPs) from cortical network activity; network gamma oscillations in particular. Alterations in gamma oscillation measurements are observed in many brain disorders. Understanding these measurements in terms of the underlying neuronal activity is crucial for developing effective therapies. Modelling can help to unravel the details of this relationship. We first investigated a reduced compartmental neuron model for use in network simulations. We showed that reduced models containing <10 compartments could reproduce the LFP characteristics of the equivalent full-scale compartmental models to a reasonable degree of accuracy. Next, we created the Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX): a Matlab tool for simulating LFPs in large, spatially organised neuronal networks. We used VERTEX to implement a large-scale neocortical slice model exhibiting gamma frequency oscillations under bath kainate application, an experimental preparation frequently used to investigate properties of gamma oscillations. We built the model based on currently available data on neocortical anatomy. By positioning a virtual electrode grid to match Utah array placement in experiments in vitro, we could make a meaningful direct comparison between simulated and experimentally recorded LFPs. We next investigated the spatial properties of the LFP in more detail, using a smaller model of neocortical layer 2/3. We made several observations about the spatial features of the LFP that shed light on past experimental recordings: how gamma power and coherence decays away from an oscillating region, how layer thickness affects the LFP, which neurons contribute most to the LFP signal, and how the LFP power scales with frequency at different model locations. Finally, we discuss the relevance of our simulation results to experimental neuroscience. Our observations on the dominance of parvalbumin-expressing basket interneuron synapses on the LFP are of particular relevance to epilepsy and schizophrenia: changes in parvalbumin expression have been observed in both disorders. We suggest how our results could inform future experiments and aid in the interpretation of their results.
APA, Harvard, Vancouver, ISO, and other styles
16

Schönecker, Sven [Verfasser]. "Non-invasive extracellular recordings of electrical activity from whole intact islets of Langerhans and the development of the medium throughput BetaScreen device / Sven Schönecker." Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1215569122/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Urbanova, Veronika. "Electrodes poreuses pour applications (bio)analytiques." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14026/document.

Full text
Abstract:
Dans cette mémoire nous discutons l´élaboration d´électrodes poreuses par un processus de type “template” et leur application potentielle dans le domaine de l´analyse environnementale et neurobiologique. La première partie de ce travail est dédiée à l'élaboration d’électrodes poreuses de bismuth et d'antimoine. Ces électrodes montrent des limites de détection améliorées par rapport à des électrodes non poreuses, ouvrant ainsi des applications prometteuses dans le domaine de l'analyse de trace. La deuxième partie vise à surmonter des facteurs limitants de micro-électrodes dans le cadre de l'enregistrement de signaux extracellulaires et la stimulation de réseaux neuronaux en culture, qui peut donner des informations sur des interactions et des phénomènes synergétiques dans les systèmes nerveux
In the present dissertation thesis the elaboration of porous electrodes via templating methods and their potential application in the field of environmental and neurobiological analysis are discussed. The electrodes of controlled porosity are characterized by an increased internal electroactive area and thus they can be used to enhance significantly the electrochemical performance. High surface area materials are promising for biosensing and more generally in electrochemical experiments. The first part of this work is focused on the elaboration of porous bismuth and antimony film electrodes. These porous electrodes show improved detection limits compared to non-porous one and thus open up promising applications in the field of trace analysis. The second part deals with overcoming limiting factors of microelectrode arrays in the context of extracellular recording and stimulating cellular neuronal networks or neural tissues in culture that can reveal information about interactions and synergetic features of nervous systems
APA, Harvard, Vancouver, ISO, and other styles
18

Camp, Nora Vanessa de [Verfasser]. "Extracellular long term recordings in the mushroom body of social insects during real and virtual navigation : decision making, drugs, ripples and replay / Nora Vanessa de Camp." Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1031100873/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

和基, 塩谷, and Kazuki Shiotani. "Olfactory cortex ventral tenia tecta neurons encode the distinct context-dependent behavioral states of goal-directed behaviors." Thesis, 櫻井 芳雄, 2003. http://id.nii.ac.jp/1707/00028191/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
20

和基, 塩谷, and Kazuki Shiotani. "Olfactory cortex ventral tenia tecta neurons encode the distinct context-dependent behavioral states of goal-directed behaviors." Thesis, 櫻井 芳雄, 2021. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13158521/?lang=0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Mateus, José Carlos Barreiro. "Optimization of a multielectrode array (MEA)-based approach to study the impact of Aβ on the SH-SY5Y cell line." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15796.

Full text
Abstract:
Mestrado em Biomedicina Molecular
The human brain stores, integrates, and transmits information recurring to millions of neurons, interconnected by countless synapses. Though neurons communicate through chemical signaling, information is coded and conducted in the form of electrical signals. Neuroelectrophysiology focus on the study of this type of signaling. Both intra and extracellular approaches are used in research, but none holds as much potential in high-throughput screening and drug discovery, as extracellular recordings using multielectrode arrays (MEAs). MEAs measure neuronal activity, both in vitro and in vivo. Their key advantage is the capability to record electrical activity at multiple sites simultaneously. Alzheimer’s disease (AD) is the most common neurodegenerative disease and one of the leading causes of death worldwide. It is characterized by neurofibrillar tangles and aggregates of amyloid-β (Aβ) peptides, which lead to the loss of synapses and ultimately neuronal death. Currently, there is no cure and the drugs available can only delay its progression. In vitro MEA assays enable rapid screening of neuroprotective and neuroharming compounds. Therefore, MEA recordings are of great use in both AD basic and clinical research. The main aim of this thesis was to optimize the formation of SH-SY5Y neuronal networks on MEAs. These can be extremely useful for facilities that do not have access to primary neuronal cultures, but can also save resources and facilitate obtaining faster high-throughput results to those that do. Adhesion-mediating compounds proved to impact cell morphology, viability and exhibition of spontaneous electrical activity. Moreover, SH-SY5Y cells were successfully differentiated and demonstrated acute effects on neuronal function after Aβ addition. This effect on electrical signaling was dependent on Aβ oligomers concentration. The results here presented allow us to conclude that the SH-SY5Y cell line can be successfully differentiated in properly coated MEAs and be used for assessing acute Aβ effects on neuronal signaling.
O cérebro humano armazena, integra e transmite informação recorrendo a milhões de neurónios, interconetados por inúmeras sinapses. Embora os neurónios comuniquem entre si através de sinais químicos, a informação é codificada e conduzida sob a forma de sinais elétricos. A neuroeletrofisiologia foca-se no estudo deste tipo de sinalização. Tanto abordagens intra, como abordagens extracelulares são usadas em investigação, mas nenhuma detém tanto potencial em screening de alto débito e na descoberta de fármacos, como medições extracelulares baseadas em matrizes de multi-elétrodos (MEA). MEAs medem a atividade neuronal, tanto em in vitro como em in vivo. A sua principal vantagem é a capacidade de medir atividade elétrica a partir de vários locais simultaneamente. A doença de Alzheimer (DA) é a doença neurodegenerativa mais comum e uma das principais causas de morte em todo o mundo. É caracterizada por emaranhados neurofibrilares e agregados de péptidos amilóides (Aβ), que conduzem à perda de sinapses e em última instância, à morte neuronal. Atualmente, não existe cura e os tratamentos disponíveis apenas retardam a sua progressão. Os ensaios in vitro com MEA permitem uma seleção rápida dos compostos neuroprotectores e neurotóxicos. Portanto, as medições com recurso a MEA são de grande utilidade na investigação básica e clínica da DA. O principal objetivo desta tese foi otimizar a formação de redes neuronais SH-SY5Y em MEAs. Estas podem ser extremamente úteis para instalações que não têm acesso a culturas neuronais primárias, mas também podem economizar recursos e facilitar a obtenção mais rápida de resultados para aquelas que têm acesso. Compostos mediadores de adesão provaram afetar a morfologia, viabilidade e a exibição espontânea de atividade elétrica das células. Além disso, as células SH-SY5Y foram diferenciadas com sucesso e demonstraram efeitos agudos sobre a função neuronal após a adição de Aβ. Este efeito sobre a sinalização elétrica foi dependente da concentração dos oligómeros de Aβ. Os resultados aqui apresentados permitem concluir que a linha celular SH-SY5Y pode ser diferenciada com sucesso em MEAs devidamente tratados e pode ser usada para avaliar os efeitos agudos do Aβ sobre a sinalização neuronal.
APA, Harvard, Vancouver, ISO, and other styles
22

Midroit, Maellie. "Signatures neurales de la perception hédonique des odeurs chez la souris." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1005/document.

Full text
Abstract:
Chez l'homme comme chez l'animal, les odeurs guident le comportement et motivent à agir. La valeur hédonique (le caractère plus ou moins plaisant) est la dimension olfactive principale et est généralement utilisée pour décider d'approcher ou fuir la source odorante. Bien que cette attractivité soit façonnée par l'expérience, certaines odeurs non-familières sont spontanément attractives ou répulsives. Le caractère plus ou moins plaisant d'une odeur serait, du moins en partie, inné. Il existerait ainsi une signature neurale spécifique de la valeur hédonique des odeurs, et c'est ce que cette thèse s'emploie à identifier.Après sélection d'odorants spontanément plus ou moins attractifs (plaisant et déplaisants respectivement), nous avons recherché les bases neurales qui sous-tendent ces comportements. Nous avons tout d'abord cartographié (expression de Zif268) puis manipulé (optogénétique) l'activité neuronale du bulbe olfactif en réponse à ces odorants, et avons révélé une signature neurale bulbaire de la valeur hédonique des odeurs le long de l'axe antéro-postérieur.Puis, afin d'analyser comment le message hédonique était interprété par les aires olfactives et associatives supérieures, nous avons développé une méthode de recalage de l'activité cérébrale dans un atlas de référence, assurant une cartographie rapide, précise et fiable de cette activité. Enfin, en combinant cette méthode à des approches comportementales, électrophysiologiques et pharmacologiques, nous avons montré un rôle du système de la récompense dans le codage de la valeur hédonique des odeurs et qu'une odeur peut être perçue comme une récompense, motivant alors les comportements d'approche et de retrait
In humans and animals, odors guide behavior and motivate action. The hedonic value (that is the pleasantness) is the main olfactory dimension and is generally used to decide to approach the odor source or move away. While this attractiveness is shaped by experience, some unfamiliar odors are spontaneously attractive or repulsive. The pleasantness of an odor would be, at least in part, innate, and suggest a specific neural signature of the hedonic value of odors. The global aim of this thesis is to decipher neuronal mechanisms underlying the hedonic value of odors.After having selected odorants with various level of attraction (pleasant and unpleasant), we have deciphered the neural bases that underlie these behaviors.We first mapped (expression of Zif268) and then manipulated (optogenetic) the neuronal activity of the olfactory bulb in response to these odors, and have revealed a bulbar neural signature of the hedonic value of odors along the antero-posterior axis.Then, in order to analyze how the hedonic information was interpreted by the higher olfactory and associative areas, we developed a method allowing the registration of brain activity in a reference atlas, that ensure a fast, accurate and reliable mapping of this activity. Finally, by combining this method with behavioral, electrophysiological and pharmacological approaches, we have shown a role of the reward system in the coding of odor hedonics and that an odor can act as a reward, thus motivating behavior, approach and withdrawal
APA, Harvard, Vancouver, ISO, and other styles
23

Varga, Adrienn Gabriella. "The Neural Basis of Head Direction and Spatial Context in the Insect Central Complex." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1487249074487484.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Vacher, Jonathan. "Synthèse de textures dynamiques pour l'étude de la vision en psychophysique et électrophysiologie." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLED005/document.

Full text
Abstract:
Le but de cette thèse est de proposer une modélisation mathématique des stimulations visuelles afin d'analyser finement des données expérimentales en psychophysique et en électrophysiologie. Plus précis\'ement, afin de pouvoir exploiter des techniques d'analyse de données issues des statistiques Bayésiennes et de l'apprentissage automatique, il est nécessaire de développer un ensemble de stimulations qui doivent être dynamiques, stochastiques et d'une complexité paramétrée. Il s'agit d'un problème important afin de comprendre la capacité du système visuel à intégrer et discriminer différents stimuli. En particulier, les mesures effectuées à de multiples échelles (neurone, population de neurones, cognition) nous permette d'étudier les sensibilités particulières des neurones, leur organisation fonctionnelle et leur impact sur la prise de décision. Dans ce but, nous proposons un ensemble de contributions théoriques, numériques et expérimentales, organisées autour de trois axes principaux : (1) un modèle de synthèse de textures dynamiques Gaussiennes spécialement paramétrée pour l'étude de la vision; (2) un modèle d'observateur Bayésien rendant compte du biais positif induit par fréquence spatiale sur la perception de la vitesse; (3) l'utilisation de méthodes d'apprentissage automatique pour l'analyse de données obtenues en imagerie optique par colorant potentiométrique et au cours d'enregistrements extra-cellulaires. Ce travail, au carrefour des neurosciences, de la psychophysique et des mathématiques, est le fruit de plusieurs collaborations interdisciplinaires
The goal of this thesis is to propose a mathematical model of visual stimulations in order to finely analyze experimental data in psychophysics and electrophysiology. More precisely, it is necessary to develop a set of dynamic, stochastic and parametric stimulations in order to exploit data analysis techniques from Bayesian statistics and machine learning. This problem is important to understand the visual system capacity to integrate and discriminate between stimuli. In particular, the measures performed at different scales (neurons, neural population, cognition) allow to study the particular sensitivities of neurons, their functional organization and their impact on decision making. To this purpose, we propose a set of theoretical, numerical and experimental contributions organized around three principal axes: (1) a Gaussian dynamic texture synthesis model specially crafted to probe vision; (2) a Bayesian observer model that accounts for the positive effect of spatial frequency over speed perception; (3) the use of machine learning techniques to analyze voltage sensitive dye optical imaging and extracellular data. This work, at the crossroads of neurosciences, psychophysics and mathematics is the fruit of several interdisciplinary collaborations
APA, Harvard, Vancouver, ISO, and other styles
25

Branchaud, Edward Allan. "A Control System for Positioning Recording Electrodes to Isolate Neurons in Extracellular Recordings." Thesis, 2006. https://thesis.library.caltech.edu/2445/1/thesis_Branchaud_Edward_A.pdf.

Full text
Abstract:

This thesis presents an algorithm that autonomously positions recording electrodes inside cortical tissue so as to isolate and then maintain optimal extracellular signal recording quality without human intervention. The algorithm is used to improve the quality and efficiency of acute (daily insertion) recordings that are needed for basic research in neurophysiology. It also offers the potential to increase the longevity and quality of chronic (long-term implant) recordings by controlling an emerging class of chronic arrays in which the electrodes can be continually repositioned after implantation.

The challenges encountered in attempting to isolate neurons are studied. A solution is proposed in which a finite state machine oversees a number of signal processing steps, computes various metrics of the recording quality and issues commands to move the electrode close to neurons without causing them damage. A number of metrics of the quality of neuron isolation are compared.

The algorithm has been used to control a number of commercial microdrive systems, including a single-electrode FHC microdrive and multielectrode microdrives from Thomas Recording and NAN, as well as a novel miniature microdrive. The autonomous positioning software is used by several neuroscientists to perform basic neurophysiology research. Analysis of the system's performance in isolating neurons is included.

APA, Harvard, Vancouver, ISO, and other styles
26

張聖任. "CMOS-micromachined, Neuro-Transistor Microsystem for Extracellular Neural Recording." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69913787364022440105.

Full text
Abstract:
博士
國立清華大學
電子工程研究所
101
Recently, research on the neuroscience is becoming a potential subject and holds a lots attraction, such as Brain Machine Interface (BMI) or the Brain-Computer Interface (BCI). The development of neuroscience not only promotes the progress of the medicine and pharmacology but also the understanding of brain function. Furthermore, the neural prosthesis is useful for patients with neural diseases to restore part of their physiological functions. The bidirectional communication is based on recording neural activity and stimulating neurons. Intracellular recording and extracellular recording are both approaches to monitored neural activity. Compared with Intracellular recording, extracellular recording has the ability to record large amount of samples and the synchronized activities. This thesis proposes a low-noise, CMOS-compatible, neuro-silicon interface for extracellular recording. For the multi-channel array system, CMOS-compatible sensor can be integrated with the recording circuit to decrease the routing complexity. The interface is based on the OSFET, which is a MOSFET with several micromachined process steps. In the experimental results, we find that OSFETs have some unideal characteristics, process variation、threshold-voltage drift and increased noise after post process. Finally, the automatic Vth-compensation feedback loop is used to overcome the biasing complex for array system. The post-CMOS process, characteristics of neuro-silicon interface, the circuit design, the influence of gate to bulk voltage for OSFET noise，and the results of biological tests are introduced in the thesis.
APA, Harvard, Vancouver, ISO, and other styles
27

Moore-Kochlacs, Caroline Elizabeth. "Extracellular electrophysiology with close-packed recording sites: spike sorting and characterization." Thesis, 2016. https://hdl.handle.net/2144/19751.

Full text
Abstract:
Advances in recording technologies now allow us to record populations of neurons simultaneously, data necessary to understand the network dynamics of the brain. Extracellular probes are fabricated with ever greater numbers of recording sites to capture the activity of increasing numbers of neurons. However, the utility of this extracellular data is limited by an initial analysis step, spike sorting, that extracts the activity patterns of individual neurons from the extracellular traces. Commonly used spike sorting methods require manual processing that limits their scalability, and errors can bias downstream analyses. Leveraging the replication of the activity from a single neuron on nearby recording sites, we designed a spike sorting method consisting of three primary steps: (1) a blind source separation algorithm to estimate the underlying source components, (2) a spike detection algorithm to find the set of spikes from each component best separated from background activity and (3) a classifier to evaluate if a set of spikes came from one individual neuron. To assess the accuracy of our method, we simulated multi-electrode array data that encompass many of the realistic variations and the sources of noise in in vivo neural data. Our method was able to extract individual simulated neurons in an automated fashion without any errors in spike assignment. Further, the number of neurons extracted increased as we increased recording site count and density. To evaluate our method in vivo, we performed both extracellular recording with our close-packed probes and a co-localized patch clamp recording, directly measuring one neuron’s ground truth set of spikes. Using this in vivo data we found that when our spike sorting method extracted the patched neuron, the spike assignment error rates were at the low end of reported error rates, and that our errors were frequently the result of failed spike detection during bursts where spike amplitude decreased into the noise. We used our in vivo data to characterize the extracellular recordings of burst activity and more generally what an extracellular electrode records. With this knowledge, we updated our spike detector to capture more burst spikes and improved our classifier based on our characterizations.
APA, Harvard, Vancouver, ISO, and other styles
28

"Single unit recording following extracellular electrical stimulation of rabbit retinal ganglion bodies." Research Laboratory of Electronics, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/4153.

Full text
Abstract:
Ralph Jensen ... [et al.].
Support from the Seaver Institute, the Lincoln Laboratory Innovative research Program, the Defence Advanced Research Projects Administration, the Lions Club, the Ziegler Foundation, and the Drown Foundation.
APA, Harvard, Vancouver, ISO, and other styles
29

Lei, Na. "Microsystem Based on CMOS Multielectrode Array for Extracellular Neural Stimulation and Recording." Thesis, 2011. https://doi.org/10.7916/D84B378B.

Full text
Abstract:
Neurobiology is constantly in search of new tools and techniques to extract structural and functional information from neural circuitry. Conventional electrophysiological stimulation and measurement technique such as patch clamping have become the standard techniques for accurate stimulation and recording of electrical activities in neurons. Nevertheless, the number of electrodes that can be introduced into the working chamber is severely limited by the electrode dimension and head stages. Integrating electrodes on chip with complementary metal-oxide-semiconductor (CMOS) technologies enables significantly higher throughput, making analysis on large neural networks possible. This thesis presents the design, characterization, verification, and post-fabrication steps of a microsystem based on a fully integrated high-density multielectrode array (MEA) chip for extracellular stimulation of neural activity. The active MEA is implemented in a standard 0.25 μm CMOS technology with 65,536 non-Faradaic electrodes in an array area of 9 mm2. Each electrode can be configured to produce unique stimulus waveform, delivering a spatial resolution exceeding 12 μm and a temporal resolution exceeding 125 nsec. The array is integrated with neurons in both dispersed culture and acute thalamocortical slices. Experimental results verify the array functionality by attaining high-resolution stimulation of dispersed primary hippocampal neuronal cultures. Neuronal activity induced from stimulation is detected through changes in real-time calcium fluorescence calibrated with cell-attached patching. Precise electrical stimulation of individual neurons is achieved by optimizing stimulation waveforms, culture preparation, and interface design. The design of a second MEA CMOS chip that integrates extracellular recording with on-chip stimulation is also presented. The chip contains 256x256 non-Faradaic circular electrodes with 14 μm diameter and 20 μm pitch. The active area of the array at 32 mm2 is designed to accommodate entire mouse thalamocortical acute slice with an electrode density of 2000 electrodes per square milimeter. Each electrode integrates with a stimulation pulse generator and a single-transistor transconductance amplifier. The new configuration does not require optical recording and reduces the mechanical setup of the microsystem.
APA, Harvard, Vancouver, ISO, and other styles
30

Denyer, Morgan C. T., M. J. Krause, M. Scholl, C. Sprossler, K. Nakajima, A. Maeliske, W. Knoll, and A. Offenhausen. "Model network architectures in vitro on extracellular recording systems using microcontact printing." 2001. http://hdl.handle.net/10454/2993.

Full text
Abstract:
No
A PDMS stamp is used to transfer a synthetic peptide in a given pattern to any suitable surface. Using this method two-dimensional neuronal model networks could be formed on glass substrates as well as on electronic devices and adjusted to the given microelectronic structure. The present work focuses on the mechanism of neurite guidance under simplified in vitro conditions, using in vitro guidance cues and outline the incorporation of these interfacial methods into microelectronic sensor devices.
APA, Harvard, Vancouver, ISO, and other styles
31

Chen, Ming-Teh, and 陳明德. "In Vivo Extracellular Recording of Striatal Neurons in the Awake Rat Following Unilateral 6-Hydroxydopamine Lesions." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/87314931819795394555.

Full text
Abstract:
博士
國防醫學院
醫學科學研究所
90
英文摘要 The purpose of this study was to further understand the functional effects of dopaminergic input to the dorsal striatum, and to compare the effects of dopaminergic lesions in awake and anesthetized animals. We examined the effects of unilateral 6-hydroxydopamine (6-OHDA) lesions of the ascending dopaminergic bundle on the firing properties of dorsal striatal neurons in the awake freely-moving rat using chronically implanted microwire electrode arrays. We recorded extracellular activity of striatal neurons under baseline conditions and following the systemic injection of apomorphine in awake and anesthetized subjects. Firing rates were higher in the hemisphere ipsilateral to the 6-OHDA lesion as compared to rates of neurons from the contralateral unlesioned hemisphere. Striatal firing rates from sham and no-surgery control rats were, in general, higher than those from the contralateral unlesioned striatum of experimental subjects. Apomorphine (0.05 mg/kg, s.c.) normalized the differences in firing rates in lesioned animals by increasing firing of neurons within the contralateral unlesioned side, while simultaneously decreasing firing of neurons within the ipsilateral lesioned side. Mean firing rates were substantially higher in awake animals than in subjects anesthetized with chloral hydrate, perhaps reflecting anesthesia-induced decreases in excitatory input to striatal neurons. Chloral hydrate anesthesia decreased firing rates of neurons in the lesioned, unlesioned, and control striata to a similar degree, although absolute firing rates of neurons from the 6-OHDA-lesioned striata remained elevated over all other groups. Unilateral 6-OHDA lesions also altered the pattern of spike output in the awake animal as indicated by an increase in the number of bursts per minute following dopaminergic deafferentation. This and other burst parameters were altered by apomorphine. Our findings show that effects of dopaminergic deafferentation can be measured in the awake behaving animal, providing a new model for testing the behavioral and functional effects of experimental manipulations designed to reduce or reverse the effects of dopaminergic cell loss. In addition, these results suggest that the contralateral changes in striatal function which occur in the unilateral dopaminergic lesion model should be considered when evaluating experimental results.
APA, Harvard, Vancouver, ISO, and other styles
32

Chen, Yung-Chan, and 陳永展. "The Design of Microsystems for Intracellular and Extracellular Neural Recording with Carbon-Nanotube-Coupled Microelectrode Array." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/56850196308423010838.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Tousson, Ehab. "Neural processing of chemosensory information from the locust ovipositor." Doctoral thesis, 2001. http://hdl.handle.net/11858/00-1735-0000-0006-ABDE-A.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Kocanda, Stanislav. "Klastrovací analýza elektrofyziologických dat." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-295830.

Full text
APA, Harvard, Vancouver, ISO, and other styles
35

Nelson, Matthew John. "Understanding and Applying Extracellular Recordings in Awake, Behaving Animals." Thesis, 2012. https://thesis.library.caltech.edu/7145/2/Matthew_Nelson_Doctoral_Thesis.pdf.

Full text
Abstract:
Section I of this thesis presents specific projects applying extracellular recordings in macaques. The results demonstrate a novel relative position code employed by individual neurons in the dorsal premotor cortex during reaches and saccades, which may be important for hand-eye coordination. Another project suggests low-frequency coherence between dorsal premotor and posterior parietal cortices participates in making internally guided decisions of where to reach. Section II investigates analysis of data collected with this technique. One project compares methodologies for computing trial-by-trial coherence among neuron ensembles, and another documents how the innate nonstationarity of animal behavior can affect conclusions of certain analyses. Section III investigates the acquisition of extracellular electrophysiological data to understand how these recorded voltages relate to underlying neural activity. One project verifies a physical model of the microelectrode recording circuit using electrodes suspended in saline. Some lower-input impedance head stages used in the field are shown to result in electrode impedance and frequency-dependent amplitude attenuations and phase shifts of recorded signals. Other projects present a theoretical argument that local field potentials (LFPs) recorded from in-depth microelectrodes should be independent of electrode impedance within the range of impedances typically used. A simple physical model shows that if and only if gradients of LFP coherence exist at a scale finer than an electrode's recording site size, lower-impedance electrodes report higher coherence. However this is not expected to occur between different microelectrodes, but could explain differences between microelectrode and EEG recordings. The final project uses simultaneous extracellular and intracellular recordings in corticostriatal rat brain slices to show that frequency-dependent phase shifts and amplitude attenuations occur in neural tissue itself and characterize the transfer function between the intracellular and extracellular voltages. Inhomogenous microscale obstructions inherent in neural tissue are shown to differentially distort current flow depending on the severity of the obstructions. This challenges existing beliefs about the nature of current flow in the brain, and should be considered when interpreting electrophysiological data.
APA, Harvard, Vancouver, ISO, and other styles
36

Rege, Jayesh. "Analysis of clustering algorithms for spike sorting of multiunit extracellular recordings." Thesis, 2000. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2000-100.

Full text
APA, Harvard, Vancouver, ISO, and other styles
37

Zhang, Tianhe. "Model Based Optimization of Spinal Cord Stimulation." Diss., 2015. http://hdl.handle.net/10161/9884.

Full text
Abstract:

Chronic pain is a distressing, prevalent, and expensive condition that is not well understood and difficult to treat. Spinal cord stimulation (SCS) has emerged as a viable means of managing chronic pain when conventional therapies are ineffective, but the efficacy of SCS has improved little since its inception. The mechanisms underlying SCS, in particular the neuronal responses to SCS, are not well understood, and prior efforts to optimize SCS have focused on electrode design and spatial selectivity without considering how the temporal aspects of SCS (stimulation frequency, pattern) may affect neuronal responses to stimulation. The lack of a biophysical basis in prior attempts to optimize therapy may have contributed to the plateau in the clinical efficacy of SCS over time. This dissertation combines computational modeling and in vivo electrophysiological approaches to investigate the effects of SCS on sensory neuron activity in the dorsal horn and uses the insights gained from these experiments to design novel temporal patterns for SCS that may be more effective than conventional therapy.

To study the mechanisms underlying SCS, we constructed a biophysically-based network model of the dorsal horn circuit consisting of interconnected dorsal horn interneurons and a wide dynamic range (WDR) projection neuron and representations of both local and surround receptive field inhibition. We validated the network model by reproducing cellular and network responses relevant to pain processing including wind-up, A-fiber mediated inhibition, and surround receptive field inhibition. To quantify experimentally the responses of spinal sensory projection neurons to SCS, we recorded the responses of antidromically identified sensory neurons in the lumbar spinal cord during 1-150 Hz SCS in both healthy rats and neuropathic rats following chronic constriction injury (CCI). In a subset of rats, we additionally assessed the impact of GABAergic inhibition on spinal neuron responses to SCS by conducting SCS experiments following the intrathecal administration of bicuculline, a GABAA receptor antagonist, and CGP 35348, a GABAB receptor antagonist. Finally, we used the computational model to design non-regular temporal patterns capable of inhibiting sensory neuron activity more effectively than conventional SCS and at lower equivalent stimulation frequencies than clinical standard 50 Hz SCS, and we experimentally validated model predictions of the improved efficacy of select patterns against conventional SCS.

Computational modeling revealed that the response of spinal sensory neurons to SCS depends on the SCS frequency; SCS frequencies of 30-100 Hz maximally inhibited the model WDR neuron consistent with clinical reports, while frequencies under 30 Hz and over 100 Hz excited the model WDR neuron. SCS-mediated inhibition was also dependent on GABAergic inhibition in the spinal cord: reducing the influence GABAergic interneurons by weakening their inputs or their connections to the model WDR neuron reduced the range of optimal SCS frequencies and changed the frequency at which SCS had a maximal effect. Experimentally, we observed that the relationship between SCS frequency and projection neuron activity predicted by the Gate Control circuit described a subset of observed SCS-frequency dependent responses but was insufficient to account for the heterogeneous responses measured experimentally. In addition, intrathecal administration of bicuculline, a GABAA receptor antagonist, increased spontaneous and evoked activity in projection neurons, enhanced excitatory responses to SCS, and reduced inhibitory responses to SCS, consistent with model predictions. Finally, computational modeling of dual frequency SCS, implemented by delivering two distinct frequencies simultaneously to distinct fiber populations, revealed frequency pairs that were more effective at inhibiting sensory neuron activity than equivalent conventional SCS and at lower average frequencies than clinically employed 50 Hz SCS. Experimental assessments of the effect of dual frequency SCS on spinal sensory neurons confirmed model predictions of greater efficacy at lower equivalent stimulation frequencies and suggest the use of non-regular temporal patterns as a novel approach to optimizing SCS. The outcomes of this dissertation are an improved understanding of the mechanisms underlying SCS, computational and experimental tools with which to continue the development and improvement of SCS. The insights and knowledge gained from the work described in this dissertation may result in translational applications that significantly improve the therapeutic outcomes of SCS and the quality of life of individuals affected by chronic pain.


Dissertation
APA, Harvard, Vancouver, ISO, and other styles
38

Taghizadeh, Bahareh. "Reference frames for planning reach movement in the parietal and premotor cortices." Doctoral thesis, 2015. http://hdl.handle.net/11858/00-1735-0000-0028-86C4-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Westendorff, Stephanie. "Neuronal mechanisms of the adaptation of conditional visuomotor behavior." Doctoral thesis, 2010. http://hdl.handle.net/11858/00-1735-0000-0006-B5D0-8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Extracellular recording' for other source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography