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1.
ACS Nano ; 18(34): 23217-23231, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39141004

RESUMEN

Flexible fiber-based microelectrodes allow safe and chronic investigation and modulation of electrically active cells and tissues. Compared to planar electrodes, they enhance targeting precision while minimizing side effects from the device-tissue mechanical mismatch. However, the current manufacturing methods face scalability, reproducibility, and handling challenges, hindering large-scale deployment. Furthermore, only a few designs can record electrical and biochemical signals necessary for understanding and interacting with complex biological systems. In this study, we present a method that utilizes the electrical conductivity and easy processability of MXenes, a diverse family of two-dimensional nanomaterials, to apply a thin layer of MXene coating continuously to commercial nylon filaments (30-300 µm in diameter) at a rapid speed (up to 15 mm/s), achieving a linear resistance below 10 Ω/cm. The MXene-coated filaments are then batch-processed into free-standing fiber microelectrodes with excellent flexibility, durability, and consistent performance even when knotted. We demonstrate the electrochemical properties of these fiber electrodes and their hydrogen peroxide (H2O2) sensing capability and showcase their applications in vivo (rodent) and ex vivo (bladder tissue). This scalable process fabricates high-performance microfiber electrodes that can be easily customized and deployed in diverse bioelectronic monitoring and stimulation studies, contributing to a deeper understanding of health and disease.


Asunto(s)
Peróxido de Hidrógeno , Microelectrodos , Peróxido de Hidrógeno/química , Animales , Vejiga Urinaria , Conductividad Eléctrica , Ratas , Técnicas Electroquímicas/instrumentación , Nanoestructuras/química
2.
Adv Sci (Weinh) ; 11(35): e2405677, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38994890

RESUMEN

Photoacoustic (PA) emitters are emerging ultrasound sources offering high spatial resolution and ease of miniaturization. Thus far, PA emitters rely on electronic transitions of absorbers embedded in an expansion matrix such as polydimethylsiloxane (PDMS). Here, it is shown that mid-infrared vibrational excitation of C─H bonds in a transparent PDMS film can lead to efficient mid-infrared photoacoustic conversion (MIPA). MIPA shows 37.5 times more efficient than the commonly used PA emitters based on carbon nanotubes embedded in PDMS. Successful neural stimulation through MIPA both in a wide field with a size up to a 100 µm radius and in single-cell precision is achieved. Owing to the low heat conductivity of PDMS, less than a 0.5 °C temperature increase is found on the surface of a PDMS film during successful neural stimulation, suggesting a non-thermal mechanism. MIPA emitters allow repetitive wide-field neural stimulation, opening up opportunities for high-throughput screening of mechano-sensitive ion channels and regulators.


Asunto(s)
Dimetilpolisiloxanos , Neuronas , Técnicas Fotoacústicas , Vibración , Dimetilpolisiloxanos/química , Técnicas Fotoacústicas/métodos , Neuronas/fisiología , Animales , Rayos Infrarrojos
3.
J Neural Eng ; 21(4)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38994790

RESUMEN

We define and explain the quasistatic approximation (QSA) as applied to field modeling for electrical and magnetic stimulation. Neuromodulation analysis pipelines include discrete stages, and QSA is applied specifically when calculating the electric and magnetic fields generated in tissues by a given stimulation dose. QSA simplifies the modeling equations to support tractable analysis, enhanced understanding, and computational efficiency. The application of QSA in neuromodulation is based on four underlying assumptions: (A1) no wave propagation or self-induction in tissue, (A2) linear tissue properties, (A3) purely resistive tissue, and (A4) non-dispersive tissue. As a consequence of these assumptions, each tissue is assigned a fixed conductivity, and the simplified equations (e.g. Laplace's equation) are solved for the spatial distribution of the field, which is separated from the field's temporal waveform. Recognizing that electrical tissue properties may be more complex, we explain how QSA can be embedded in parallel or iterative pipelines to model frequency dependence or nonlinearity of conductivity. We survey the history and validity of QSA across specific applications, such as microstimulation, deep brain stimulation, spinal cord stimulation, transcranial electrical stimulation, and transcranial magnetic stimulation. The precise definition and explanation of QSA in neuromodulation are essential for rigor when using QSA models or testing their limits.


Asunto(s)
Estimulación Magnética Transcraneal , Humanos , Estimulación Magnética Transcraneal/métodos , Modelos Neurológicos , Estimulación Encefálica Profunda/métodos , Estimulación Eléctrica/métodos , Animales , Simulación por Computador
4.
Neurophotonics ; 11(2): 025003, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38800606

RESUMEN

Significance: Pulsed infrared neural stimulation (INS, 1875 nm) is an emerging neurostimulation technology that delivers focal pulsed heat to activate functionally specific mesoscale networks and holds promise for clinical application. However, little is known about its effect on excitatory and inhibitory cell types in cerebral cortex. Aim: Estimates of summed population neuronal response time courses provide a potential basis for neural and hemodynamic signals described in other studies. Approach: Using two-photon calcium imaging in mouse somatosensory cortex, we have examined the effect of INS pulse train application on hSyn neurons and mDlx neurons tagged with GCaMP6s. Results: We find that, in anesthetized mice, each INS pulse train reliably induces robust response in hSyn neurons exhibiting positive going responses. Surprisingly, mDlx neurons exhibit negative going responses. Quantification using the index of correlation illustrates responses are reproducible, intensity-dependent, and focal. Also, a contralateral activation is observed when INS applied. Conclusions: In sum, the population of neurons stimulated by INS includes both hSyn and mDlx neurons; within a range of stimulation intensities, this leads to overall excitation in the stimulated population, leading to the previously observed activations at distant post-synaptic sites.

5.
PNAS Nexus ; 3(2): pgae082, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38725532

RESUMEN

Deep brain stimulation (DBS) is a powerful tool for the treatment of circuitopathy-related neurological and psychiatric diseases and disorders such as Parkinson's disease and obsessive-compulsive disorder, as well as a critical research tool for perturbing neural circuits and exploring neuroprostheses. Electrically mediated DBS, however, is limited by the spread of stimulus currents into tissue unrelated to disease course and treatment, potentially causing undesirable patient side effects. In this work, we utilize infrared neural stimulation (INS), an optical neuromodulation technique that uses near to midinfrared light to drive graded excitatory and inhibitory responses in nerves and neurons, to facilitate an optical and spatially constrained DBS paradigm. INS has been shown to provide spatially constrained responses in cortical neurons and, unlike other optical techniques, does not require genetic modification of the neural target. We show that INS produces graded, biophysically relevant single-unit responses with robust information transfer in rat thalamocortical circuits. Importantly, we show that cortical spread of activation from thalamic INS produces more spatially constrained response profiles than conventional electrical stimulation. Owing to observed spatial precision of INS, we used deep reinforcement learning (RL) for closed-loop control of thalamocortical circuits, creating real-time representations of stimulus-response dynamics while driving cortical neurons to precise firing patterns. Our data suggest that INS can serve as a targeted and dynamic stimulation paradigm for both open and closed-loop DBS.

6.
Micromachines (Basel) ; 15(5)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38793223

RESUMEN

In this paper, we report a low-cost printing process of carbon nanotube (CNT)-based, all-organic microelectrode arrays (MEAs) suitable for in vitro neural stimulation and recording. Conventional MEAs have been mainly composed of expensive metals and manufactured through high-cost and complex lithographic processes, which have limited their accessibility for neuroscience experiments and their application in various studies. Here, we demonstrate a printing-based fabrication method for microelectrodes using organic CNT/paraffin ink, coupled with the deposition of an insulating layer featuring single-cell-sized sensing apertures. The simple microfabrication processes utilizing the economic and readily available ink offer potential for cost reduction and improved accessibility of MEAs. Biocompatibility of the fabricated microelectrode was suggested through a live/dead assay of cultured neural cells, and its large electric double layer capacitance was revealed by cyclic voltammetry that was crucial for preventing cytotoxic electrolysis during electric neural stimulation. Furthermore, the electrode exhibited sufficiently low electric impedance of 2.49 Ω·cm2 for high signal-to-noise ratio neural recording, and successfully captured model electric waves in physiological saline solution. These results suggest the easily producible and low-cost printed all-organic microelectrodes are available for neural stimulation and recording, and we believe that they can expand the application of MEA in various neuroscience research.

7.
J Neural Eng ; 21(5)2024 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-38579740

RESUMEN

Objective.In neural electrical stimulation, safe stimulation guidelines are essential to deliver efficient treatment while avoiding neural damage and electrode degradation. The widely used Shannon's limit,k, gives conditions on the stimulation parameters to avoid neural damage, however, underlying damage mechanisms are not fully understood. Moreover, the translation from bench testing toin vivoexperiments still presents some challenges, including the increased polarisation observed, which may influence charge-injection mechanisms. In this work, we studied the influence on damage mechanisms of two electrolyte parameters that are differentin vivocompared to usual bench tests: solution pH and electrolyte gelation.Approach.The potential of a platinum macroelectrode was monitored in a three-electrode setup during current-controlled biphasic charge-balanced cathodic-first pulse trains. Maximum anodic and cathodic potential excursions during pulse trains were projected on cyclic voltammograms to infer possible electrochemical reactions.Main results.In unbuffered saline of pH ranging from 1 to 12, the maximum anodic potential was systematically located in the oxide formation region, while the cathodic potential was located the molecular oxygen and oxide reduction region whenkapproached Shannon's damage limit, independent of solution pH. The results support the hypothesis that Shannon's limit corresponds to the beginning of platinum dissolution following repeated cycles of platinum oxidation and reduction, for which the cathodic excursion is a key tipping point. Despite similar potential excursions between solution and gel electrolytes, we found a joint influence of pH and gelation on the cathodic potential alone, while we observed no effect on the anodic potential. We hypothesise that gelation creates a positive feedback loop exacerbating the effects of pH ; however, the extent of that influence needs to be examined further.Significance.This work supports the hypothesis of charge injection mechanisms associated with stimulation-induced damage at platinum electrodes. The validity of a major hypothesis explaining stimulation-induced damage was tested and supported on a range of electrolytes representing potential electrode environments, calling for further characterisation of platinum dissolution during electrical stimulation in various testing conditions.


Asunto(s)
Estimulación Eléctrica , Electrodos , Platino (Metal) , Solución Salina , Platino (Metal)/química , Concentración de Iones de Hidrógeno , Solución Salina/química , Solución Salina/administración & dosificación , Estimulación Eléctrica/métodos
8.
Adv Mater ; 36(26): e2400346, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38594598

RESUMEN

Bioelectricity plays a crucial role in organisms, being closely connected to neural activity and physiological processes. Disruptions in the nervous system can lead to chaotic ionic currents at the injured site, causing disturbances in the local cellular microenvironment, impairing biological pathways, and resulting in a loss of neural functions. Electromagnetic stimulation has the ability to generate internal currents, which can be utilized to counter tissue damage and aid in the restoration of movement in paralyzed limbs. By incorporating implanted materials, electromagnetic stimulation can be targeted more accurately, thereby significantly improving the effectiveness and safety of such interventions. Currently, there have been significant advancements in the development of numerous promising electromagnetic stimulation strategies with diverse materials. This review provides a comprehensive summary of the fundamental theories, neural stimulation modulating materials, material application strategies, and pre-clinical therapeutic effects associated with electromagnetic stimulation for neural repair. It offers a thorough analysis of current techniques that employ materials to enhance electromagnetic stimulation, as well as potential therapeutic strategies for future applications.


Asunto(s)
Materiales Biocompatibles , Humanos , Animales , Materiales Biocompatibles/química , Terapia por Estimulación Eléctrica/métodos , Terapia por Estimulación Eléctrica/instrumentación
9.
J Neural Eng ; 21(2)2024 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-38408386

RESUMEN

Objective.This study aims to develop and validate a sophisticated fork-shaped neural interface (FNI) designed for peripheral nerves, focusing on achieving high spatial resolution, functional selectivity, and improved charge storage capacities. The objective is to create a neurointerface capable of precise neuroanatomical analysis, neural signal recording, and stimulation.Approach.Our approach involves the design and implementation of the FNI, which integrates 32 multichannel working electrodes featuring enhanced charge storage capacities and low impedance. An insertion guide holder is incorporated to refine neuronal selectivity. The study employs meticulous electrode placement, bipolar electrical stimulation, and comprehensive analysis of induced neural responses to verify the FNI's capabilities. Stability over an eight-week period is a crucial aspect, ensuring the reliability and durability of the neural interface.Main results.The FNI demonstrated remarkable efficacy in neuroanatomical analysis, exhibiting accurate positioning of motor nerves and successfully inducing various movements. Stable impedance values were maintained over the eight-week period, affirming the durability of the FNI. Additionally, the neural interface proved effective in recording sensory signals from different hind limb areas. The advanced charge storage capacities and low impedance contribute to the FNI's robust performance, establishing its potential for prolonged use.Significance.This research represents a significant advancement in neural interface technology, offering a versatile tool with broad applications in neuroscience and neuroengineering. The FNI's ability to capture both motor and sensory neural activity positions it as a comprehensive solution for neuroanatomical studies. Moreover, the precise neuromodulation potential of the FNI holds promise for applications in advanced bionic prosthetic control and therapeutic interventions. The study's findings contribute to the evolving field of neuroengineering, paving the way for enhanced understanding and manipulation of peripheral neural functions.


Asunto(s)
Nervios Periféricos , Ratas , Animales , Reproducibilidad de los Resultados , Electrodos Implantados , Nervios Periféricos/fisiología , Estimulación Eléctrica
10.
J Obstet Gynaecol Res ; 50(3): 438-447, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38148300

RESUMEN

OBJECTIVE: This study aimed to determine the effect of progressive relaxation exercises (PRE) and transcutaneous electrical nerve stimulation administered to women delivering via cesarean delivery on acute pain, breastfeeding success, and comfort levels. METHODS: This is a single-blind, randomized controlled study. This study was carried out in the obstetrics and gynecology clinic of a university hospital affiliated with the Ministry of Health in Turkey between August 20, 2018 and April 15, 2019. A total of 120 participants were randomly assigned to one of four groups, which included a transcutaneous electrical neural stimulation (TENS) group, a PRE group, a combined intervention group, and a control group. Data were collected with a Data Collection Form, The Visual Analogue Scale, The LATCH Breastfeeding Diagnostic Tool, and The Postpartum Comfort Scale. RESULTS: According to the findings of the study, it was determined that pain significantly decreased and comfort increased after having a cesarean delivery in all three intervention groups compared to the control group (p < 0.05). Regarding the breastfeeding success, while there was no statistically significant change in this behavior in the TENS group, it was significantly better in the PRE group and the combined intervention group, where TENS and PRE were administered together (p < 0.05). CONCLUSIONS: According to our study results, we recommend that TENS and PRE should be employed together after a cesarean delivery as safe non-pharmacological methods in pain management, eliminating breastfeeding problems, and increasing comfort.


Asunto(s)
Estimulación Eléctrica Transcutánea del Nervio , Embarazo , Femenino , Humanos , Estimulación Eléctrica Transcutánea del Nervio/métodos , Lactancia Materna , Método Simple Ciego , Entrenamiento Autogénico , Dolor
11.
J Neurosurg Case Lessons ; 6(24)2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-38079629

RESUMEN

BACKGROUND: Responsive neural stimulation (RNS) is a relatively novel procedure for drug-resistant epilepsy, which involves implantation of a device into the skull and brain. As more devices are implanted, there may be an increasing need to perform intracranial electrocorticography in implant patients with persistent seizures. Given the device location, imaging difficulties with implanted devices, and other technical hurdles, stereoelectroencephalography (SEEG) could be especially challenging. The authors describe the first reported SEEG investigation in a patient with an RNS device, highlighting the technical challenges and clinical data ascertained. OBSERVATIONS: A 41-year-old male with drug-resistant epilepsy presented several years after a local surgeon had placed an RNS device with two electrodes in the bilateral parieto-occipital lobes. Because of inadequate seizure control, the patient was offered a repeat SEEG investigation to characterize his epilepsy better. Although more technically challenging than a traditional SEEG implantation, the SEEG investigation was successfully performed, which led to a confirmation of bilateral hippocampal seizure onset. The patient underwent repositioning of his RNS leads with a significant decrease in his seizure frequency. LESSONS: Concurrent implantation of SEEG electrodes in a functioning RNS device can be safely performed and can augment our understanding of a patient's seizures.

12.
Inquiry ; 60: 469580231221286, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38145317

RESUMEN

Addiction remains difficult to treat, but non-invasive transcranial electrical and magnetic neurostimulation methods may provide promising and cost-effective treatment approaches. We provide a narrative review of recent developments and evidence of effectiveness and consider newer technology that may yield improved treatment approaches. In particular, we review temporal interference electrical neurostimulation, which allows non-invasive and focal stimulation of deep brain regions. This provides a promising new potential approach to treat addiction, because many of the brain regions that seem most important for addiction are deeper in the brain, out of reach of existing technologies such as transcranial direct current stimulation.


Asunto(s)
Conducta Adictiva , Trastornos Relacionados con Sustancias , Estimulación Transcraneal de Corriente Directa , Humanos , Conducta Adictiva/terapia , Trastornos Relacionados con Sustancias/terapia
13.
J Transl Gastroenterol ; 1(1): 47-56, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38009094

RESUMEN

Background and objectives: In this systematic review, we evaluated the efficacy, mechanisms and safety of three neuromodulation therapies in patients with gastroesophageal reflux disease (GERD), including the effect of neuromodulation therapies on symptoms and key GERD pathophysiologies, lower esophageal sphincter (LES) pressure, esophageal motility, gastric motility, and parasympathetic activity. The first therapy is LES electrical stimulation using an implantable electrical stimulator, the second is transcutaneous electrical acustimulation, and the third is manual acupuncture. Methods: A systematic review of literature according to the PRISMA guidelines was performed. Online databases searched include Medline (Ovid), Embase, and PubMed. Studies were assessed for inclusion and exclusion criteria with Covidence, a systematic review software. Results: The analysis included thirteen clinical studies. Four papers included were registered under two open-label trials on ClinicalTrials.gov for LES electrical stimulation; Five randomized trials with sham-treated controls were analyzed for transcutaneous electrical acustimulation; Four studies, including three involving standard therapy controls and one involving shamtreated controls were included for manual acupuncture. All evaluated studies demonstrated significant beneficial effects on GERD symptoms, using patient-completed questionnaires, objective 24-h measurement of esophageal pH, and patient-reported use of proton pump inhibitors. In evaluating the effect on key GERD pathophysiologies, electrical stimulation significantly increased LES pressure, and transcutaneous electrical acustimulation significantly improved esophageal motility, gastric motility, and parasympathetic activity. None of the evaluated neuromodulation methods produced severe adverse effects. Conclusions: Cumulative evidence from the evaluated studies indicates that neuromodulation therapies were effective in treating the GERD symptoms and key underlying GERD pathophysiologies. They are thus valuable options for individualized GERD treatment.

15.
bioRxiv ; 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37904955

RESUMEN

Deep brain stimulation (DBS) is a powerful tool for the treatment of circuitopathy-related neurological and psychiatric diseases and disorders such as Parkinson's disease and obsessive-compulsive disorder, as well as a critical research tool for perturbing neural circuits and exploring neuroprostheses. Electrically-mediated DBS, however, is limited by the spread of stimulus currents into tissue unrelated to disease course and treatment, potentially causing undesirable patient side effects. In this work, we utilize infrared neural stimulation (INS), an optical neuromodulation technique that uses near to mid-infrared light to drive graded excitatory and inhibitory responses in nerves and neurons, to facilitate an optical and spatially constrained DBS paradigm. INS has been shown to provide spatially constrained responses in cortical neurons and, unlike other optical techniques, does not require genetic modification of the neural target. We show that INS produces graded, biophysically relevant single-unit responses with robust information transfer in thalamocortical circuits. Importantly, we show that cortical spread of activation from thalamic INS produces more spatially constrained response profiles than conventional electrical stimulation. Owing to observed spatial precision of INS, we used deep reinforcement learning for closed-loop control of thalamocortical circuits, creating real-time representations of stimulus-response dynamics while driving cortical neurons to precise firing patterns. Our data suggest that INS can serve as a targeted and dynamic stimulation paradigm for both open and closed-loop DBS.

16.
Front Neurosci ; 17: 1210537, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37650106

RESUMEN

Scalp acupuncture (SA), as a modern acupuncture therapy in the treatment of brain diseases, especially for acute ischemic strokes, has accumulated a wealth of experience and tons of success cases, but the current hypothesized mechanisms of SA therapy still seem to lack significant scientific validity, which may not be conducive to its ultimate integration into mainstream medicine. This review explores a novel perspective about the mechanisms of SA in treating brain diseases based on its effects on cerebral blood flow (CBF). To date, abundant evidence has shown that CBF is significantly increased by stimulating specific SA points, areas or nerves innervating the scalp, which parallels the instant or long-term improvement of symptoms of brain diseases. Over time, the neural pathways that improve CBF by stimulating the trigeminal, the facial, and the cervical nerves have also been gradually revealed. In addition, the presence of the core SA points or areas frequently used for brain diseases can be rationally explained by the characteristics of nerve distribution, including nerve overlap or convergence in certain parts of the scalp. But such characteristics also suggest that the role of these SA points or areas is relatively specific and not due to a direct correspondence between the current hypothesized SA points, areas and the functional zones of the cerebral cortex. The above evidence chain indicates that the efficacy of SA in treating brain diseases, especially ischemic strokes, is mostly achieved by stimulating the scalp nerves, especially the trigeminal nerve to improve CBF. Of course, the mechanisms of SA in treating various brain diseases might be multifaceted. However, the authors believe that understanding the neural regulation of SA on CBF not only captures the main aspects of the mechanisms of SA therapy, but also facilitates the elucidation of other mechanisms, which may be of greater significance to further its clinical applications.

17.
Adv Sci (Weinh) ; 10(25): e2301854, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37386797

RESUMEN

Optoelectronic biointerfaces have gained significant interest for wireless and electrical control of neurons. Three-dimentional (3D) pseudocapacitive nanomaterials with large surface areas and interconnected porous structures have great potential for optoelectronic biointerfaces that can fulfill the requirement of high electrode-electrolyte capacitance to effectively transduce light into stimulating ionic currents. In this study, the integration of 3D manganese dioxide (MnO2 ) nanoflowers into flexible optoelectronic biointerfaces for safe and efficient photostimulation of neurons is demonstrated. MnO2 nanoflowers are grown via chemical bath deposition on the return electrode, which has a MnO2 seed layer deposited via cyclic voltammetry. They facilitate a high interfacial capacitance (larger than 10 mF cm-2 ) and photogenerated charge density (over 20 µC cm-2 ) under low light intensity (1 mW mm-2 ). MnO2 nanoflowers induce safe capacitive currents with reversible Faradaic reactions and do not cause any toxicity on hippocampal neurons in vitro, making them a promising material for biointerfacing with electrogenic cells. Patch-clamp electrophysiology is recorded in the whole-cell configuration of hippocampal neurons, and the optoelectronic biointerfaces trigger repetitive and rapid firing of action potentials in response to light pulse trains. This study points out the potential of electrochemically-deposited 3D pseudocapacitive nanomaterials as a robust building block for optoelectronic control of neurons.


Asunto(s)
Electroquímica , Luz , Compuestos de Manganeso , Nanoestructuras , Neuronas , Óxidos , Potenciales de Acción/efectos de la radiación , Capacidad Eléctrica , Electroquímica/métodos , Electrodos , Electrólitos/química , Electrólitos/efectos de la radiación , Electrofisiología , Hipocampo/citología , Compuestos de Manganeso/química , Nanoestructuras/efectos adversos , Nanoestructuras/química , Nanoestructuras/efectos de la radiación , Neuronas/metabolismo , Neuronas/efectos de la radiación , Óxidos/química , Técnicas de Placa-Clamp , Estimulación Luminosa , Tecnología Inalámbrica , Humanos , Animales , Ratas
18.
Neuroimage ; 276: 120185, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37244320

RESUMEN

OBJECTIVE: Blood-oxygen-level-dependent functional MRI allows to investigte neural activities and connectivity. While the non-human primate plays an essential role in neuroscience research, multimodal methods combining functional MRI with other neuroimaging and neuromodulation enable us to understand the brain network at multiple scales. APPROACH: In this study, a tight-fitting helmet-shape receive array with a single transmit loop for anesthetized macaque brain MRI at 7T was fabricated with four openings constructed in the coil housing to accommodate multimodal devices, and the coil performance was quantitatively evaluated and compared to a commercial knee coil. In addition, experiments over three macaques with infrared neural stimulation (INS), focused ultrasound stimulation (FUS), and transcranial direct current stimulation (tDCS) were conducted. MAIN RESULTS: The RF coil showed higher transmit efficiency, comparable homogeneity, improved SNR and enlarged signal coverage over the macaque brain. Infrared neural stimulation was applied to the amygdala in deep brain region, and activations in stimulation sites and connected sites were detected, with the connectivity consistent with anatomical information. Focused ultrasound stimulation was applied to the left visual cortex, and activations were acquired along the ultrasound traveling path, with all time course curves consistent with pre-designed paradigms. The existence of transcranial direct current stimulation electrodes brought no interference to the RF system, as evidenced through high-resolution MPRAGE structure images. SIGNIFICANCE: This pilot study reveals the feasibility for brain investigation at multiple spatiotemporal scales, which may advance our understanding in dynamic brain networks.


Asunto(s)
Estimulación Transcraneal de Corriente Directa , Animales , Haplorrinos , Proyectos Piloto , Imagen por Resonancia Magnética , Neuroimagen , Encéfalo/diagnóstico por imagen , Macaca , Diseño de Equipo , Fantasmas de Imagen , Ondas de Radio , Relación Señal-Ruido
19.
Biomed Eng Lett ; 13(2): 209-219, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37124115

RESUMEN

Heating nanoparticles with a magnetic field could facilitate selective remote control of neural activity in deep tissue. However, current magnetothermal stimulation approaches are limited to single-channel stimulation. Here, we investigated various designs for multichannel magnetothermal stimulation based on an array of resonant coils that are driven by a single loop coil. Using a tuning capacitor that allows resonant coils to resonate at the operating frequency, each coil's ON and OFF resonance can be controlled, enabling us to select stimulation channels. We found that smaller inner diameters of resonant coils produce more localized magnetic fields while larger coils produce magnetic fields over a longer distance. The constructed multichannel resonant coil arrays can provide a high enough magnetic field intensity to raise the temperature of nanoparticles by 8 °C when we apply 35.2 W into the loop coil that is spaced 1 mm from the target neurons. This multichannel stimulation using a simple resonant circuit approach would be useful for clinical applications of magnetothermal neural stimulation.

20.
J Neurosci Res ; 101(8): 1360-1379, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37186320

RESUMEN

Neuroinflammation is a reaction of nervous tissue to an attack caused by an infection, a toxin, or a neurodegenerative disease. It involves brain metabolism adaptation in order to meet the increased energy needs of glial cell activation, but the nature of these adaptations is still unknown. Increasing interest concerning neuroinflammation leads to the identification of its role in neurodegenerative diseases. Few reports studied the effect of metabolic alteration on neuroinflammation. Metabolic damage initiates a pro-inflammatory response by microglial activation. Moreover, the exact neuroinflammation effect on cerebral cell metabolism remains unknown. In this study, we reviewed systematically the neuroinflammation effect in animal models' brains. All articles showing the relationship of neuroinflammation with brain metabolism, or with neuronal stimulation in neurodegenerative diseases were considered. Moreover, this review examines also the mitochondrial damage effect in neurodegeneration diseases. Then, different biosensors are classified regarding their importance in the determination of metabolite change. Finally, some therapeutic drugs inhibiting neuroinflammation are cited. Neuroinflammation increases lymphocyte infiltration and cytokines' overproduction, altering cellular energy homeostasis. This review demonstrates the importance of neuroinflammation as a mediator of disease progression. Further, the spread of depolarization effects pro-inflammatory genes expression and microglial activation, which contribute to the degeneration of neurons, paving the road to better management and treatment of neurodegenerative diseases.


Asunto(s)
Encefalitis , Enfermedades Neurodegenerativas , Animales , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neuroinflamatorias , Encéfalo/metabolismo , Encefalitis/metabolismo , Neuronas/metabolismo , Microglía/metabolismo , Inflamación/metabolismo
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