Planar amorphous silicon carbide microelectrode arrays for chronic recording in rat motor cortex

Biomaterials, Год журнала: 2024, Номер 308, С. 122543 - 122543

Опубликована: Март 21, 2024

Язык: Английский

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Cortical Response to Acute Implantation of the Utah Optrode Array in Macaque Cortex

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Янв. 15, 2025

Optogenetics has transformed the study of neural circuit function, but limitations in its application to species with large brains, such as non-human primates (NHPs), remain. A major challenge NHP optogenetics is delivering light sufficiently volumes deep tissue high spatiotemporal precision, without simultaneously affecting superficial tissue. To overcome these limitations, we recently developed and tested vivo cortex, Utah Optrode Array (UOA). This a 10×10 array penetrating glass shanks, tiling 4×4mm 2 area, bonded interleaved needle-aligned interstitial µLED arrays, which allows for independent photostimulation brain Here, investigate acute biological response UOA implantation goal optimizing device design reduced insertion trauma subsequent chronic response. this goal, systematically vary shank diameter, surface texture, tip geometry, pressure, assess their effects on astrocytes, microglia, neuronal viability, following implantation. We find that UOAs shanks smaller smooth texture round tips cause least damage. Higher pressures have limited inflammatory response, lead greater compression. Our results highlight importance balancing pressure preserving integrity improving long-term performance biocompatibility.

Язык: Английский

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Anisotropic hydrogel microelectrodes for intraspinal neural recordings in vivo

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 28, 2025

Creating durable, motion-compliant neural interfaces is crucial for accessing dynamic tissues under in vivo conditions and linking activity with behaviors. Utilizing the self-alignment of nano-fillers a polymeric matrix repetitive tension, here, we introduce conductive carbon nanotubes high aspect ratios into semi-crystalline polyvinyl alcohol hydrogels, create electrically anisotropic percolation pathways through cyclic stretching. The resulting hydrogel fibers (diameter 187 ± 13 µm) exhibit fatigue resistance (up to 20,000 cycles at 20% strain) stretchability 64.5 7.9% low electrochemical impedance (33.20 9.27 kΩ @ 1 kHz cm length). We observe reconstructed nanofillers' axial alignment corresponding decrease along direction fabricate fiber-shaped hydrogels bioelectronic devices implant them wild-type transgenic Thy1::ChR2-EYFP mice record electromyographic signals from muscles anesthetized freely moving conditions. These effectively enable simultaneous recording electrical ventral spinal cord neurons tibialis anterior during optogenetic stimulation. Importantly, maintain functionality intraspinal electrophysiology recordings over eight months after implantation, demonstrating their durability potential long-term monitoring neurophysiological studies. essential Here, authors nanotube-enhanced creating anisotropic, fatigue-resistant electrophysiological mice.

Язык: Английский

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Longitudinal, Multimodal Tracking Reveals Lasting Neurovascular Impact of Individual Microinfarcts

Advanced Science, Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

Abstract Microinfarcts, the “invisible lesions”, are prevalent in aged and injured brains associated with cognitive impairments, yet their neurophysiological impact remains largely unknown. Using a multimodal chronic neural platform that combines functional microvasculature imaging spatially resolved recording, neurovascular effect of single microinfarct is investigated. Unlike larger strokes, microinfarcts induced only temporary suppression activity minimal cell death, recovery paralleling vasculature remodeling at infarct core. Neural more severely suppressed shallower cortical layer despite milder vascular damage compared to deeper layers, excitability fast‐spiking interneurons attenuation accompanied by heightened bursting regular spiking neurons. Spike phase locking low‐gamma band disrupted, indicating lasting impairment long‐range assembly communication. These results highlight subtle significant disruptions microinfarct.

Язык: Английский

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Rapid learning and integration of artificial sensation

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Апрель 19, 2025

1 Summary Prosthetic limbs lack proprioceptive feedback, which is essential for complex movements. Intracortical mi-crostimulation (ICMS) elicits sensory perceptions that could serve as an artificial signal. However, movements guided by ICMS are slower and less accurate than those with natural sensation. Here, we developed a freely-moving mouse behavioral task to improve encoding of Mice implanted 16-channel microwire arrays in primary somatosensory cortex were trained navigate targets upon the floor custom training cage. Target location was encoded visual and/or feedback. quickly learned use signal locate invisible targets, achieving 75% proficiency on ICMS-only trials first three sessions testing. Furthermore, performance multimodal significantly exceeded unimodal performance, demonstrating animals integrated vision This protocol can be applied efficiently develop test algorithms encode proprioception neural prostheses.

Язык: Английский

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Nanotopography-enhanced biomimetic coating maintains bioactivity after weeks of dry storage and improves chronic neural recording

Biomaterials, Год журнала: 2023, Номер 302, С. 122326 - 122326

Опубликована: Сен. 12, 2023

Язык: Английский

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Deciphering platinum dissolution in neural stimulation electrodes: Electrochemistry or biology?

Biomaterials, Год журнала: 2024, Номер 309, С. 122575 - 122575

Опубликована: Апрель 17, 2024

Platinum (Pt) is the metal of choice for electrodes in implantable neural prostheses like cochlear implants, deep brain stimulating devices, and brain-computer interfacing technologies. However, it well known since 1970s that Pt dissolution occurs with electrical stimulation. More recent clinical vivo studies have shown signs corrosion explanted electrode arrays presence Pt-containing particulates tissue samples. The process degradation release metallic ions particles can significantly impact on device performance. Moreover, effects products health function are still largely unknown. This due to highly complex chemistry underlying difficulty decoupling chemical biological responses. Understanding mechanisms proves challenging as be influenced by electrical, chemical, physical, factors, all them variable between experimental settings. By evaluating comprehensive findings reported fuel cell field, this review presents a critical analysis possible drive stimulation vitro vivo. Stimulation parameters, such aggregate charge, charge density, electrochemical potential levels dissolved Pt. factors electrolyte types, gases, pH influence dissolution, confounding multiple variables. Biological proteins, been documented exhibit mitigating effect process. Other cells fibro-proliferative responses, fibrosis gliosis, properties suspected dissolution. relationship remains contentious. Host responses also controversial unknown compounds formed lack understanding distribution scenarios. cytotoxicity produced via appears similar Pt-based compounds, including hexachloroplatinates chemotherapeutic agents cisplatin. While under acute regimes were typically an order magnitude lower than toxic concentrations observed vitro, further research needed accurately assess mass balance type during long-term its response. Finally, approaches reviewed. A wide variety approaches, strategies, coating materials, surface modification techniques avoid excess minimise response, may ultimately support safe operation devices.

Язык: Английский

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Through-polymer, via technology-enabled, flexible, lightweight, and integrated devices for implantable neural probes

Microsystems & Nanoengineering, Год журнала: 2024, Номер 10(1)

Опубликована: Апрель 22, 2024

Abstract In implantable electrophysiological recording systems, the headstage typically comprises neural probes that interface with brain tissue and integrated circuit chips for signal processing. While advancements in MEMS CMOS technology have significantly improved these components, their interconnection still relies on conventional printed boards sophisticated adapters. This approach adds considerable weight volume to package, especially high channel count systems. To address this issue, we developed a through-polymer via (TPV) method inspired by through-silicon (TSV) technique advanced three-dimensional packaging. innovation enables vertical integration of flexible probes, amplifier chips, PCBs, realizing flexible, lightweight, device (FLID). The total FLIDis only 25% its counterparts relying adapters, which increased activity levels animals wearing FLIDs nearly match control without implants. Furthermore, incorporating platinum-iridium alloy as top layer material electrical contact, FLID realizes exceptional performance, enabling vivo measurements both local field potentials individual neuron action potentials. These findings showcase potential scaling up systems mark significant advancement neurotechnology.

Язык: Английский

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基于锥形光纤-超柔电极的神经接口光电伪影分析

Chinese Journal of Lasers, Год журнала: 2025, Номер 52(3), С. 0307301 - 0307301

Опубликована: Янв. 1, 2025

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Spatially and temporally mismatched blood flow and neuronal activity by high-intensity intracortical microstimulation

Brain stimulation, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Intracortial microstimulation (ICMS) is widely used in neuroprosthetic brain-machine interfacing, particularly restoring lost sensory and motor functions. Spiking neuronal activity requires increased cerebral blood flow to meet local metabolic demands, a process conventionally denoted as neurovascular coupling (NVC). However, it unknown precisely how what extent ICMS elicits NVC the responses correlate. Suboptimal by may compromise oxygen energy delivery activated neurons thus impair functionality. We wide-field imaging (WFI), laser speckle (LSI) two-photon microscopy (TPM) study living, transgenic mice expressing calcium (Ca2+) fluorescent indicators either or vascular mural cells (VMC), well measure inner lumen diameters. By testing range of stimulation amplitudes examining cortical tissue at different distances from stimulating electrode tip, we found that high intensities (≥ 50 μA) elicited spatial temporal decoupling regions most adjacent tip (< 200 μm), with significantly delayed onset times compromised maximum increases. attribute these effects respectively Ca2+ signalling decreased sensitivity VMCs. Our offers new insights into ICMS-associated physiology potentially critical implications towards optimal design therapies: low preserve NVC; disrupt precipitate supply deficits.

Язык: Английский

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