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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 888-893, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018127

RESUMO

Micro-electrode recording (MER) is a powerful way of localizing target structures during neurosurgical procedures such as the implantation of deep brain stimulation electrodes, which is a common treatment for Parkinson's disease and other neurological disorders. While Micro-electrode Recording (MER) provides adjunctive information to guidance assisted by pre-operative imaging, it is not unanimously used in the operating room. The lack of standard use of MER may be in part due to its long duration, which can lead to complications during the operation, or due to high degree of expertise required for their interpretation. Over the past decade, various approaches addressing automating MER analysis for target localization have been proposed, which have mainly focused on feature engineering. While the accuracies obtained are acceptable in certain configurations, one issue with handcrafted MER features is that they do not necessarily capture more subtle differences in MER that could be detected auditorily by an expert neurophysiologist. In this paper, we propose and validate a deep learning-based pipeline for subthalamic nucleus (STN) localization with micro-electrode recordings motivated by the human auditory system. Our proposed Convolutional Neural Network (CNN), referred as SepaConvNet, shows improved accuracy over two comparative networks for locating the STN from one second MER samples.


Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Núcleo Subtalâmico , Eletrodos Implantados , Humanos , Microeletrodos , Doença de Parkinson/terapia
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1112-1115, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018181

RESUMO

Deep brain stimulation (DBS) is used to treat a range of neurologic conditions. Determining the anatomic location of the DBS lead and inferring the microelectrode recording track from co-registered pre-operative and post-operative scans is important for stereotactic surgery and neurophysiology research. Reslicing images with the DBS lead in-plane while maintaining mirror symmetry is not possible with current clinical navigation software. Therefore, we developed an open source software tool in Matlab for visualizing DBS lead placement and anatomic segmentation with computed tomography and magnetic resonance images. The code and graphical user interface are available at: github.com/camplaboratory/DBS_reslice.


Assuntos
Estimulação Encefálica Profunda , Eletrodos Implantados , Humanos , Imagem por Ressonância Magnética , Microeletrodos , Tomografia Computadorizada por Raios X
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3083-3085, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018656

RESUMO

Bi-directional brain-computer interfaces (BD-BCI) to restore movement and sensation must achieve concurrent operation of recording and decoding of motor commands from the brain and stimulating the brain with somatosensory feedback. Previously we developed and validated a benchtop prototype of a fully implantable BCI system for motor decoding. Here, a prototype artificial sensory stimulator was integrated into the benchtop system to develop a prototype of a fully-implantable BD-BCI. The artificial sensory stimulator incorporates an active charge balancing mechanism based on pulse-width modulation to ensure safe stimulation for chronically interfaced electrodes to prevent damage to brain tissue and electrodes. The feasibility of the BD-BCI system's active charge balancing was tested in phantom brain tissue. With the charge-balancing, the removal of the residual charges on an electrode was evident. This is a critical milestone toward fully-implantable BD-BCI systems.


Assuntos
Interfaces Cérebro-Computador , Encéfalo , Eletrodos Implantados , Movimento , Sensação
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3379-3383, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018729

RESUMO

This paper presents a neurosurgical device called NEIT 2 (Nerve Electrode Insertion Tool) to implant a 3D microelectrode array into a peripheral nervous system. Using an elastomer-made nerve holder, the device is able to stable target a flexible nerve, and then safely inserts an electrode array into the fixed nerve. Finally, a nerve containment assembly is made at once. We conducted animal experiments to evaluate the proposed scenario using a 3D printed prototype and commercial microelectrodes. The results show that microelectrodes are successfully implanted into sciatic nerves of rats and neural signals are recorded through the chronically implanted electrodes.


Assuntos
Nervo Isquiático , Animais , Eletrodos Implantados , Microeletrodos , Ratos
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3432-3435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018741

RESUMO

Many advances have been made with imaging of implanted neural devices; however, the ability to image whole nerve samples remains limited. Further, few imaging modalities are well suited for visualizing both whole devices in vivo and individual microelectrodes within a nerve. In this study, we used micro-computed tomography (micro-CT) to evaluate Wireless Floating Microelectrode Arrays (WMFAs) implanted in rat sciatic nerve at the level of whole devices and individual electrodes. WFMAs were also used to track selective recruitment of plantar flexion and dorsiflexion of the rear paw, which was achieved by each implanted device (n=6) during chronic implantation. Evoked limb motion was correlated to end-of-study assessments using micro-CT to visualize electrode locations within the fascicular structure of the sciatic nerve. Results of this study show that micro-CT imaging can provide valuable assessments of microelectrode arrays implanted in peripheral nerves for both whole devices visualized in vivo and individual electrodes visualized in whole nerve tissue samples.Clinical relevance- This work informs the use of micro-computed tomography as a tool for correlating neural device performance with physical attributes of the implant location.


Assuntos
Nervo Isquiático , Animais , Eletrodos Implantados , Microeletrodos , Ratos , Nervo Isquiático/diagnóstico por imagem , Microtomografia por Raio-X
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3634-3637, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018789

RESUMO

Deep brain stimulation (DBS) involves activation of targeted brain tissue through implantable electrodes to treat neurological disorders. In this study, two novel electrode designs, recessed flat-contact and recessed curvature-contact models were developed where the electrode contacts were recessed to a specified depth to improve directional selectivity. Furthermore, the contact geometry was also modified for the recessed curvature-contact model in order to obtain a hemispherical configuration that will help increase current steering and reduce the propensity of tissue damage. The predicted tissue damage produced by these models were compared to the standard array model using the Shannon tissue damage model criteria. Furthermore, the volume of tissue activated by each of the electrode models was analyzed, and the radial projection relative to the total projection of each geometry was determined as a measure of directional selectivity. Based on the trends observed in the current density, tissue damage, and volume of tissue activated (VTA) analyses, it is inferred that the recessed contact electrode geometries help improve directional selectivity and safety of DBS.


Assuntos
Estimulação Encefálica Profunda , Encéfalo , Eletrodos Implantados , Matemática , Modelos Neurológicos
8.
J Vis Exp ; (162)2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32894266

RESUMO

Brainwaves amplitude obtained from electroencephalography (EEG) has been well-recognized as a basis for cognitive capacity, memory, and learning on animals and humans. Adult neurogenesis mechanism is also linked to memory and learning improvement. Traditionally, researchers used to assess learning and memory parameters in rodent models by behavioral tasks. Therefore, the simultaneous monitoring of behavioral changes and EEG is particularly interesting in correlating data between brain activity and task-related behaviors. However, most of the equipment required to perform both studies are either complex, expensive, or uses a wired setup network that hinders the natural animals' movement. In this study, EEG was recorded with a wireless electrophysiology device along with the execution of a novel object recognition task (NORT). The animal's behavior was monitored simultaneously by a video tracking system. Both recordings were analyzed offline by their timestamps which were synched to link EEG signals with the animal's actions. Subjects consist of adult Wistar rats after medium-term environmental enrichment treatment. Six skull screw electrodes were fixed in pairs on both hemispheres over frontal, central, and parietal regions and were referenced to an electrode located posterior of the nasal bone. NORT protocol consists of exposing the animal to two identical objects for 10 min. After 2 h and 24 h, one of the objects was replaced with a novel one. Exploration time for each object was monitored by a behavioral tracking software (BTS) and EEG data recording. The analysis of the EEG synced with behavioral data consists of estimations of alpha and beta relative band power and comparisons between novel object recognition versus familiar object exploration, between three experimental stages. In this manuscript, we have discussed electrodes manufacturing process, epidural electrodes implantation surgery, environmental enrichment protocol, NORT protocol, BTS setup, EEG - BTS coupling for simultaneous monitoring in real-time, and EEG data analysis based on automatic events detection.


Assuntos
Comportamento Animal/fisiologia , Eletroencefalografia/métodos , Hipocampo/fisiologia , Memória/fisiologia , Tecnologia sem Fio , Animais , Ondas Encefálicas/fisiologia , Eletrodos Implantados , Eletroencefalografia/instrumentação , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Masculino , Neurogênese , Ratos , Ratos Wistar
9.
Nat Protoc ; 15(10): 3129-3153, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32989306

RESUMO

Peripheral neural interfaces have been successfully used in the recent past to restore sensory-motor functions in disabled subjects and for the neuromodulation of the autonomic nervous system. The optimization of these neural interfaces is crucial for ethical, clinical and economic reasons. In particular, hybrid models (HMs) constitute an effective framework to simulate direct nerve stimulation and optimize virtually every aspect of implantable electrode design: the type of electrode (for example, intrafascicular versus extrafascicular), their insertion position and the used stimulation routines. They are based on the combined use of finite element methods (to calculate the voltage distribution inside the nerve due to the electrical stimulation) and computational frameworks such as NEURON ( https://neuron.yale.edu/neuron/ ) to determine the effects of the electric field generated on the neural structures. They have already provided useful results for different applications, but the overall usability of this powerful approach is still limited by the intrinsic complexity of the procedure. Here, we illustrate a general, modular and expandable framework for the application of HMs to peripheral neural interfaces, in which the correct degree of approximation required to answer different kinds of research questions can be readily determined and implemented. The HM workflow is divided into the following tasks: identify and characterize the fiber subpopulations inside the fascicles of a given nerve section, determine different degrees of approximation for fascicular geometries, locate the fibers inside these geometries and parametrize electrode geometries and the geometry of the nerve-electrode interface. These tasks are examined in turn, and solutions to the most relevant issues regarding their implementation are described. Finally, some examples related to the simulation of common peripheral neural interfaces are provided.


Assuntos
Estimulação Elétrica/métodos , Neuroestimuladores Implantáveis/tendências , Eletrodos Implantados/tendências , Humanos , Nervos Periféricos/fisiologia , Próteses e Implantes
10.
Nat Commun ; 11(1): 4686, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943633

RESUMO

Electrophysiology provides a direct readout of neuronal activity at a temporal precision only limited by the sampling rate. However, interrogating deep brain structures, implanting multiple targets or aiming at unusual angles still poses significant challenges for operators, and errors are only discovered by post-hoc histological reconstruction. Here, we propose a method combining the high-resolution information about bone landmarks provided by micro-CT scanning with the soft tissue contrast of the MRI, which allowed us to precisely localize electrodes and optic fibers in mice in vivo. This enables arbitrating the success of implantation directly after surgery with a precision comparable to gold standard histology. Adjustment of the recording depth with micro-drives or early termination of unsuccessful experiments saves many working hours, and fast 3-dimensional feedback helps surgeons avoid systematic errors. Increased aiming precision enables more precise targeting of small or deep brain nuclei and multiple targeting of specific cortical or hippocampal layers.


Assuntos
Encéfalo/diagnóstico por imagem , Eletrodos Implantados , Processamento de Imagem Assistida por Computador/métodos , Fibras Ópticas , Microtomografia por Raio-X/métodos , Animais , Comportamento Animal , Encéfalo/patologia , Mapeamento Encefálico , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Hipocampo/cirurgia , Técnicas Histológicas/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Silício , Técnicas Estereotáxicas
11.
Nat Commun ; 11(1): 4550, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917862

RESUMO

Place cells exhibit spatially selective firing fields that collectively map the continuum of positions in environments; how such activity pattern develops with experience is largely unknown. Here, we record putative granule cells (GCs) and mossy cells (MCs) from the dentate gyrus (DG) over 27 days as mice repetitively run through a sequence of objects fixed onto a treadmill belt. We observe a progressive transformation of GC spatial representations, from a sparse encoding of object locations and spatial patterns to increasingly more single, evenly dispersed place fields, while MCs show little transformation and preferentially encode object locations. A competitive learning model of the DG reproduces GC transformations via the progressive integration of landmark-vector cells and spatial inputs and requires MC-mediated feedforward inhibition to evenly distribute GC representations, suggesting that GCs slowly encode conjunctions of objects and spatial information via competitive learning, while MCs help homogenize GC spatial representations.


Assuntos
Fibras Musgosas Hipocampais/fisiologia , Células de Lugar/fisiologia , Aprendizagem Espacial/fisiologia , Potenciais de Ação/fisiologia , Animais , Eletrodos Implantados , Eletroencefalografia/instrumentação , Masculino , Camundongos , Modelos Animais , Técnicas Estereotáxicas/instrumentação
12.
Nat Commun ; 11(1): 4191, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826892

RESUMO

The nascent field of bioelectronic medicine seeks to decode and modulate peripheral nervous system signals to obtain therapeutic control of targeted end organs and effectors. Current approaches rely heavily on electrode-based devices, but size scalability, material and microfabrication challenges, limited surgical accessibility, and the biomechanically dynamic implantation environment are significant impediments to developing and deploying peripheral interfacing technologies. Here, we present a microscale implantable device - the nanoclip - for chronic interfacing with fine peripheral nerves in small animal models that begins to meet these constraints. We demonstrate the capability to make stable, high signal-to-noise ratio recordings of behaviorally-linked nerve activity over multi-week timescales. In addition, we show that multi-channel, current-steering-based stimulation within the confines of the small device can achieve multi-dimensional control of a small nerve. These results highlight the potential of new microscale design and fabrication techniques for realizing viable devices for long-term peripheral interfacing.


Assuntos
Microeletrodos , Nervos Periféricos/fisiologia , Impressão Tridimensional , Animais , Engenharia Biomédica , Eletrodos Implantados , Potenciais Evocados , Tentilhões/fisiologia , Masculino , Microtecnologia , Modelos Animais , Nervos Periféricos/cirurgia , Razão Sinal-Ruído
13.
PLoS One ; 15(8): e0237537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785286

RESUMO

BACKGROUND: An accurate and precise surgical procedure is crucial for patient safety and treatment efficacy of deep brain stimulation (DBS). OBJECTIVES: To investigate the characteristics of intracranial lead bending phenomenon after DBS, and to suggest the methods to avoid bending-related complications. METHODS: A retrospective review of brain computed tomography scans after DBS was performed. Using 3-dimensional reconstruction, the maximal distance between the planned trajectory and actual lead location was measured. When the distance exceeded the lead body diameter, the lead was considered bent. The distance between the bending point and planned trajectory, and the relative direction between the bending point and lead securing site were analyzed. Changes over time in the range of lead bending and depth were analyzed when possible. RESULTS: A total of 190 implanted leads in 102 patients were analyzed; 104 leads (54.7%) were bent. The average deviation of bent leads was 2.3 mm (range, 1.3-7.1 mm). Thirty-five (18.4%) and seven leads (3.7%) had deviations exceeding twice and three times the lead body diameter, respectively. Angles between the deviation point and securing site at the skull ranged from 135-180° in 83 leads (53.2%), 45-135° in 58 (37.2%), and 0-45° in 15 (9.6%). Among 17 leads that were initially bent, 16 had less deviation compared to baseline. The lead depth increased in 35 (92.1%) of 38 leads by 1.2 mm (range, 0.1-4.7 mm). CONCLUSION: The extent of lead bending should be considered during the planning and procedural phases of intracranial lead implantation for DBS.


Assuntos
Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Eletrodos Implantados , Transtornos dos Movimentos/terapia , Neuroimagem/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/diagnóstico por imagem , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
14.
PLoS Biol ; 18(8): e3000851, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32822389

RESUMO

High levels of the amyloid-beta (Aß) peptide have been shown to disrupt neuronal function and induce hyperexcitability, but it is unclear what effects Aß-associated hyperexcitability may have on tauopathy pathogenesis or propagation in vivo. Using a novel transgenic mouse line to model the impact of human APP (hAPP)/Aß accumulation on tauopathy in the entorhinal cortex-hippocampal (EC-HIPP) network, we demonstrate that hAPP overexpression aggravates EC-Tau aggregation and accelerates pathological tau spread into the hippocampus. In vivo recordings revealed a strong role for hAPP/Aß, but not tau, in the emergence of EC neuronal hyperactivity and impaired theta rhythmicity. Chronic chemogenetic attenuation of EC neuronal hyperactivity led to reduced hAPP/Aß accumulation and reduced pathological tau spread into downstream hippocampus. These data strongly support the hypothesis that in Alzheimer's disease (AD), Aß-associated hyperactivity accelerates the progression of pathological tau along vulnerable neuronal circuits, and demonstrates the utility of chronic, neuromodulatory approaches in ameliorating AD pathology in vivo.


Assuntos
Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Córtex Entorrinal/metabolismo , Tauopatias/genética , Proteínas tau/genética , Potenciais de Ação/fisiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Dependovirus/genética , Dependovirus/metabolismo , Modelos Animais de Doenças , Eletrodos Implantados , Córtex Entorrinal/patologia , Feminino , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Neurônios/patologia , Agregados Proteicos , Técnicas Estereotáxicas , Tauopatias/metabolismo , Tauopatias/patologia , Tauopatias/terapia , Ritmo Teta/fisiologia , Transdução Genética , Transgenes , Proteínas tau/metabolismo
15.
J Vis Exp ; (161)2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32744520

RESUMO

Peripheral nerve cuff electrodes have long been used in the neurosciences and related fields for stimulation of, for example, vagus or sciatic nerves. Several recent studies have demonstrated the effectiveness of chronic VNS in enhancing central nervous system plasticity to improve motor rehabilitation, extinction learning, and sensory discrimination. Construction of chronically implantable devices for use in such studies is challenging due to rats' small size, and typical protocols require extensive training of personnel and time-consuming microfabrication methods. Alternatively, commercially available implantable cuff electrodes can be purchased at a significantly higher cost. In this protocol, we present a simple, low-cost method for construction of small, chronically implantable peripheral nerve cuff electrodes for use in rats. We validate the short and long-term reliability of our cuff electrodes by demonstrating that VNS in ketamine/xylazine anesthetized rats produces decreases in breathing rate consistent with activation of the Hering-Breuer reflex, both at the time of implantation and up to 10 weeks after device implantation. We further demonstrate the suitability of the cuff electrodes for use in chronic stimulation studies by pairing VNS with skilled lever press performance to induce motor cortical map plasticity.


Assuntos
Eletrodos Implantados , Estimulação do Nervo Vago/instrumentação , Animais , Ratos , Reprodutibilidade dos Testes , Fatores de Tempo
16.
N Engl J Med ; 383(6): 526-536, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32757521

RESUMO

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) was designed to avoid complications related to the transvenous ICD lead by using an entirely extrathoracic placement. Evidence comparing these systems has been based primarily on observational studies. METHODS: We conducted a noninferiority trial in which patients with an indication for an ICD but no indication for pacing were assigned to receive a subcutaneous ICD or transvenous ICD. The primary end point was the composite of device-related complications and inappropriate shocks; the noninferiority margin for the upper boundary of the 95% confidence interval for the hazard ratio (subcutaneous ICD vs. transvenous ICD) was 1.45. A superiority analysis was prespecified if noninferiority was established. Secondary end points included death and appropriate shocks. RESULTS: A total of 849 patients (426 in the subcutaneous ICD group and 423 in the transvenous ICD group) were included in the analyses. At a median follow-up of 49.1 months, a primary end-point event occurred in 68 patients in the subcutaneous ICD group and in 68 patients in the transvenous ICD group (48-month Kaplan-Meier estimated cumulative incidence, 15.1% and 15.7%, respectively; hazard ratio, 0.99; 95% confidence interval [CI], 0.71 to 1.39; P = 0.01 for noninferiority; P = 0.95 for superiority). Device-related complications occurred in 31 patients in the subcutaneous ICD group and in 44 in the transvenous ICD group (hazard ratio, 0.69; 95% CI, 0.44 to 1.09); inappropriate shocks occurred in 41 and 29 patients, respectively (hazard ratio, 1.43; 95% CI, 0.89 to 2.30). Death occurred in 83 patients in the subcutaneous ICD group and in 68 in the transvenous ICD group (hazard ratio, 1.23; 95% CI, 0.89 to 1.70); appropriate shocks occurred in 83 and 57 patients, respectively (hazard ratio, 1.52; 95% CI, 1.08 to 2.12). CONCLUSIONS: In patients with an indication for an ICD but no indication for pacing, the subcutaneous ICD was noninferior to the transvenous ICD with respect to device-related complications and inappropriate shocks. (Funded by Boston Scientific; PRAETORIAN ClinicalTrials.gov number, NCT01296022.).


Assuntos
Arritmias Cardíacas/terapia , Desfibriladores Implantáveis/efeitos adversos , Idoso , Cardiomiopatias/terapia , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/prevenção & controle , Eletrodos Implantados/efeitos adversos , Falha de Equipamento , Feminino , Seguimentos , Cardiopatias/terapia , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Desenho de Prótese
17.
PLoS One ; 15(8): e0237709, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817653

RESUMO

OBJECTIVES: In this paper, we aim to detail the setup of a high spatio-temporal resolution, electrical recording system utilising planar microelectrode arrays with simultaneous optical imaging suitable for evaluating microelectrode performance with a proposed 'performance factor' metric. METHODS: Techniques that would facilitate low noise electrical recordings were coupled with voltage sensitive dyes and neuronal activity was recorded both electrically via a customised amplification system and optically via a high speed CMOS camera. This technique was applied to characterise microelectrode recording performance of gold and poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) coated electrodes through traditional signal to noise (SNR) calculations as well as the proposed performance factor. RESULTS: Neuronal activity was simultaneously recorded using both electrical and optical techniques and this activity was confirmed via tetrodotoxin application to inhibit action potential firing. PEDOT/PSS outperformed gold using both measurements, however, the performance factor metric estimated a 3 fold improvement in signal transduction when compared to gold, whereas SNR estimated an 8 fold improvement when compared to gold. CONCLUSION: The design and functionality of a system to record from neurons both electrically, through microelectrode arrays, and optically via voltage sensitive dyes was successfully achieved. SIGNIFICANCE: The high spatiotemporal resolution of both electrical and optical methods will allow for an array of applications such as improved detection of subthreshold synaptic events, validation of spike sorting algorithms and a provides a robust evaluation of extracellular microelectrode performance.


Assuntos
Potenciais de Ação/fisiologia , Eletrodos Implantados , Microeletrodos , Neurônios/fisiologia , Algoritmos , Ouro/química , Humanos , Polímeros/química , Transdução de Sinais/fisiologia
18.
J Laryngol Otol ; 134(6): 493-496, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32618542

RESUMO

OBJECTIVE: Safe cochlear implantation is challenging in patients with canal wall down mastoid cavities, and the presence of large meatoplasties increases the risk of external canal overclosure. This paper describes our results of obliteration of the mastoid cavity with conchal cartilage as an alternative procedure in cases of canal wall down mastoidectomy with very large meatoplasty. METHODS: The cases of seven patients with a canal wall down mastoidectomy cavity who underwent cochlear implantation were retrospectively reviewed. Post-operative complications were analysed. The mean follow-up duration was 4.5 years. RESULTS: There was no hint of cholesteatoma recurrence and all patients have been free of symptoms during follow up. Only one patient showed cable extrusion six months after surgery, and implantation of the contralateral ear was needed. CONCLUSION: Pseudo-obliteration of the mastoid cavity with a cartilage multi-layered palisade reconstruction covering the electrode may be a safe alternative in selected patients with a large meatoplasty.


Assuntos
Cartilagem/transplante , Meato Acústico Externo/cirurgia , Processo Mastoide/cirurgia , Mastoidectomia/efeitos adversos , Adulto , Idoso , Colesteatoma da Orelha Média/epidemiologia , Doença Crônica , Implante Coclear/métodos , Eletrodos Implantados/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Processo Mastoide/patologia , Pessoa de Meia-Idade , Otite Média/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Procedimentos Cirúrgicos Reconstrutivos/métodos , Recidiva , Estudos Retrospectivos
19.
Nat Commun ; 11(1): 3364, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620886

RESUMO

Multiple surgical targets for treating obsessive-compulsive disorder with deep brain stimulation (DBS) have been proposed. However, different targets may modulate the same neural network responsible for clinical improvement. We analyzed data from four cohorts of patients (N = 50) that underwent DBS to the anterior limb of the internal capsule (ALIC), the nucleus accumbens or the subthalamic nucleus (STN). The same fiber bundle was associated with optimal clinical response in cohorts targeting either structure. This bundle connected frontal regions to the STN. When informing the tract target based on the first cohort, clinical improvements in the second could be significantly predicted, and vice versa. To further confirm results, clinical improvements in eight patients from a third center and six patients from a fourth center were significantly predicted based on their stimulation overlap with this tract. Our results show that connectivity-derived models may inform clinical improvements across DBS targets, surgeons and centers. The identified tract target is openly available in atlas form.


Assuntos
Conectoma/psicologia , Estimulação Encefálica Profunda/métodos , Modelos Neurológicos , Transtorno Obsessivo-Compulsivo/terapia , Adulto , Estimulação Encefálica Profunda/instrumentação , Eletrodos Implantados , Feminino , Seguimentos , Humanos , Cápsula Interna/fisiopatologia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/fisiopatologia , Núcleo Accumbens/fisiopatologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Transtorno Obsessivo-Compulsivo/psicologia , Período Pós-Operatório , Período Pré-Operatório , Prognóstico , Estudos Retrospectivos , Núcleo Subtalâmico/fisiopatologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
20.
Nat Commun ; 11(1): 3661, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32694504

RESUMO

The relationship between orexin/hypocretin and rapid eye movement (REM) sleep remains elusive. Here, we find that a proportion of orexin neurons project to the sublaterodorsal tegmental nucleus (SLD) and exhibit REM sleep-related activation. In SLD, orexin directly excites orexin receptor-positive neurons (occupying ~3/4 of total-population) and increases gap junction conductance among neurons. Their interaction spreads the orexin-elicited partial-excitation to activate SLD network globally. Besides, the activated SLD network exhibits increased probability of synchronized firings. This synchronized excitation promotes the correspondence between SLD and its downstream target to enhance SLD output. Using optogenetics and fiber-photometry, we consequently find that orexin-enhanced SLD output prolongs REM sleep episodes through consolidating brain state activation/muscle tone inhibition. After chemogenetic silencing of SLD orexin signaling, a ~17% reduction of REM sleep amounts and disruptions of REM sleep muscle atonia are observed. These findings reveal a stabilization role of orexin in REM sleep.


Assuntos
Tronco Encefálico/fisiologia , Orexinas/metabolismo , Privação do Sono/fisiopatologia , Sono REM/fisiologia , Potenciais de Ação/fisiologia , Animais , Comportamento Animal , Tronco Encefálico/citologia , Modelos Animais de Doenças , Eletrodos Implantados , Eletroencefalografia , Eletromiografia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Tono Muscular/fisiologia , Neurônios/metabolismo , Optogenética , Receptores de Orexina/metabolismo , Orexinas/genética , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Vigília/fisiologia
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