Multielectrode Arrays

Author(s):  
Russell Burley ◽  
Jenna R. M. Harvey
2001 ◽  
Vol 89 (7) ◽  
pp. 1013-1029 ◽  
Author(s):  
W. Rutten ◽  
J.-M. Mouveroux ◽  
J. Buitenweg ◽  
C. Heida ◽  
T. Ruardij ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Y. M. Wang ◽  
Vickie H. Y. Wong ◽  
Pei Ying Lee ◽  
Bang V. Bui ◽  
Stefanie Dudczig ◽  
...  

AbstractThere is increasing evidence for the vulnerability of specific retinal ganglion cell (RGC) types in those with glaucoma and in animal models. In addition, the P2X7-receptor (P2X7-R) has been suggested to contribute to RGC death following stimulation and elevated IOP, though its role in RGC dysfunction prior to death has not been examined. Therefore, we examined the effect of an acute, non-ischemic intraocular pressure (IOP) insult (50 mmHg for 30 min) on RGC function in wildtype mice and P2X7-R knockout (P2X7-KO) mice. We examined retinal function using electroretinogram recordings and individual RGC responses using multielectrode arrays, 3 days following acute IOP elevation. Immunohistochemistry was used to examine RGC cell death and P2X7-R expression in several RGC types. Acute intraocular pressure elevation produced pronounced dysfunction in RGCs; whilst other retinal neuronal responses showed lesser changes. Dysfunction at 3 days post-injury was not associated with RGC loss or changes in receptive field size. However, in wildtype animals, OFF-RGCs showed reduced spontaneous and light-elicited activity. In the P2X7-KO, both ON- and OFF-RGC light-elicited responses were reduced. Expression of P2X7-R in wildtype ON-RGC dendrites was higher than in other RGC types. In conclusion, OFF-RGCs were vulnerable to acute IOP elevation and their dysfunction was not rescued by genetic ablation of P2X7-R. Indeed, knockout of P2X7-R also caused ON-RGC dysfunction. These findings aid our understanding of how pressure affects RGC function and suggest treatments targeting the P2X7-R need to be carefully considered.


2018 ◽  
Vol 119 (4) ◽  
pp. 1471-1484 ◽  
Author(s):  
E. Ferrea ◽  
L. Suriya-Arunroj ◽  
D. Hoehl ◽  
U. Thomas ◽  
A. Gail

Acute neuronal recordings performed with metal microelectrodes in nonhuman primates allow investigating the neural substrate of complex cognitive behaviors. Yet the daily reinsertion and positioning of the electrodes prevents recording from many neurons simultaneously, limiting the suitability of these types of recordings for brain-computer interface applications or for large-scale population statistical methods on a trial-by-trial basis. In contrast, chronically implanted multielectrode arrays offer the opportunity to record from many neurons simultaneously, but immovable electrodes prevent optimization of the signal during and after implantation and cause the tissue response to progressively impair the transduced signal quality, thereby limiting the number of different neurons that can be recorded over the lifetime of the implant. Semichronically implanted matrices of electrodes, instead, allow individually movable electrodes in depth and achieve higher channel count compared with acute methods, hence partially overcoming these limitations. Existing semichronic systems with higher channel count lack computerized control of electrode movements, leading to limited user-friendliness and uncertainty in depth positioning. Here we demonstrate a chronically implantable adaptive multielectrode positioning system with detachable drive for computerized depth adjustment of individual electrodes over several millimeters. This semichronic 16-channel system is designed to optimize the simultaneous yield of units in an extended period following implantation since the electrodes can be independently depth adjusted with minimal effort and their signal quality continuously assessed. Importantly, the electrode array is designed to remain within a chronic recording chamber for a prolonged time or can be used for acute recordings with high signal-to-noise ratio in the cerebral cortex of nonhuman primates. NEW & NOTEWORTHY We present a 16-channel motorized, semichronic multielectrode array with individually depth-adjustable electrodes to record in the cerebral cortex of nonhuman primates. Compared with fixed-geometry arrays, this system allows repeated reestablishing of single neuron isolation. Compared with manually adjustable arrays it benefits from computer-controlled positioning. Compared with motorized semichronic systems it allows higher channel counts due to a robotic single actuator approach. Overall the system is designed to optimize the simultaneous yield of units over the course of implantation.


2020 ◽  
Vol 117 (27) ◽  
pp. 15482-15489 ◽  
Author(s):  
Jie Ju ◽  
Ning Hu ◽  
Dana M. Cairns ◽  
Haitao Liu ◽  
Brian P. Timko

Bioelectronic scaffolds that support devices while promoting tissue integration could enable tissue hybrids with augmented electronic capabilities. Here, we demonstrate a photo–cross-linkable silk fibroin (PSF) derivative and investigate its structural, electrical, and chemical properties. Lithographically defined PSF films offered tunable thickness and <1-µm spatial resolution and could be released from a relief layer yielding freestanding scaffolds with centimeter-scale uniformity. These constructs were electrically insulating; multielectrode arrays with PSF-passivated interconnects provided stable electrophysiological readouts from HL-1 cardiac model cells, brain slices, and hearts. Compared to SU8, a ubiquitous biomaterial, PSF exhibited superior affinity toward neurons which we attribute to its favorable surface charge and enhanced attachment of poly-d-lysine adhesion factors. This finding is of significant importance in bioelectronics, where tight junctions between devices and cell membranes are necessary for electronic communication. Collectively, our findings are generalizable to a variety of geometries, devices, and tissues, establishing PSF as a promising bioelectronic platform.


2018 ◽  
Vol 12 ◽  
Author(s):  
Micha E. Spira ◽  
Nava Shmoel ◽  
Shun-Ho M. Huang ◽  
Hadas Erez

Author(s):  
Muneeb Zia ◽  
Bryce Chung ◽  
Samuel Sober ◽  
Muhannad S. Bakir

2015 ◽  
Vol 114 (2) ◽  
pp. 869-878 ◽  
Author(s):  
Spencer C. Chen ◽  
John W. Morley ◽  
Samuel G. Solomon

The middle temporal (MT) area is a cortical area integral to the “where” pathway of primate visual processing, signaling the movement and position of objects in the visual world. The receptive field of a single MT neuron is sensitive to the direction of object motion but is too large to signal precise spatial position. Here, we asked if the activity of MT neurons could be combined to support the high spatial precision required in the where pathway. With the use of multielectrode arrays, we recorded simultaneously neural activity at 24–65 sites in area MT of anesthetized marmoset monkeys. We found that although individual receptive fields span more than 5° of the visual field, the combined population response can support fine spatial discriminations (<0.2°). This is because receptive fields at neighboring sites overlapped substantially, and changes in spatial position are therefore projected onto neural activity in a large ensemble of neurons. This fine spatial discrimination is supported primarily by neurons with receptive fields flanking the target locations. Population performance is degraded (by 13–22%) when correlations in neural activity are ignored, further reflecting the contribution of population neural interactions. Our results show that population signals can provide high spatial precision despite large receptive fields, allowing area MT to represent both the motion and the position of objects in the visual world.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Maria V. Vedunova ◽  
Tatiana A. Mishchenko ◽  
Elena V. Mitroshina ◽  
Irina V. Mukhina

The neuroprotective and antihypoxic effects of brain-derived neurotrophic factor (BDNF) on dissociated hippocampal cultures in a hypoxia model were investigated. These experiments demonstrate that 10 minutes of normobaric hypoxia increased the number of dead cells in primary culture, whereas a preventive application of BDNF increased the number of viable cells. Spontaneous bioelectrical and calcium activity in neural networks was analyzed using multielectrode arrays and functional intravital calcium imaging. The results indicate that BDNF affects the functional parameters of neuronal networks in dissociated hippocampal cultures over the 7-day posthypoxic period. In addition, the effects of k252a, an antagonist of tropomyosin-related kinase B (TrkB), on functional bioelectrical activity during and after acute hypoxia were investigated. It was shown that the protective effects of BDNF are associated with binding to the TrkB receptor. Finally, intravital fluorescent mRNA probes were used to study the role of NF-κB1 in the protective effects of BDNF. Our experiments revealed that BDNF application stimulates NF-κB1 mRNA synthesis in primary dissociated hippocampal cells under normal conditions but not in hypoxic state.


Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 235-235
Author(s):  
Hemmings Wu ◽  
Kai Joshua Miller ◽  
Zack Blumenfeld ◽  
Nolan Williams ◽  
Vinod Karthik Ravikumar ◽  
...  

Abstract INTRODUCTION Impulsivity is one of the most pervasive and disabling features common to many brain disorders. Heightened responsivity in the nucleus accumbens (NAc) during anticipation of rewarding stimuli predisposes to impulsivity. Electrophysiological correlates have been reported during brief windows of anticipation, which have potential to inform a novel therapeutic to deliver a time-sensitive intervention. But no available neuromodulaion therapy is capable of sensing and therapeutically responding to this vulnerable moment. The objectives of our research are: to identify biomarkers of anticipation of highly-reinforcing food reward in mouse NAc, to use these biomarkers to guide responsive neurostimulation (RNS) to suppress binge-like behavior, and to examine the effect of RNS on other behaviors, such as social interaction. METHODS Multielectrode arrays were implanted into the mouse NAc, and were put on a limited high-fat (HF) exposure protocol known to induce binge-like behavior. Power spectral density analyses of NAc local field potentials (LFPs) before HF intake were performed to identify electrophysiological biomarkers. Identical analyses were performed before house chow intake. RNS was triggered whenever potential biomarkers appeared, and reduction in HF intake induced by RNS was examined. RNS was applied during juvenile interaction test to assess behavioral specificity. RESULTS >Increased delta oscillations were observed immediately prior to HF intake after mice developed binge-like behavior, which was not detected immediately prior to chow intake. RNS utilizing delta power as biomarker significantly reduced HF intake. RNS showed no significant effect on juvenile interaction, while continuous deep brain stimulation (DBS) significantly reduced it. CONCLUSION Our findings demonstrate that NAc LFPs carry critical information relevant to reward anticipation, and have the potential to be used as an electrographic biomarker to guide RNS for neuropsychiatric disorders exhibiting impulsivity. Compared to continuous DBS, RNS has the advantage of targeting specific psychiatric symptom while potentially sparing other behaviors.


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