scholarly journals Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 430 ◽  
Author(s):  
Andrew Campbell ◽  
Chengyuan Wu
Keyword(s):  
Tissue Reaction ◽  
Tissue Response ◽  
Significant Progress ◽  
Electrode Implantation ◽  
Disease States ◽  
Electrode Interface ◽  
Intracranial Electrodes ◽  
Electrode Systems ◽  
The Brain ◽  
Made In

The brain-electrode interface is arguably one of the most important areas of study in neuroscience today. A stronger foundation in this topic will allow us to probe the architecture of the brain in unprecedented functional detail and augment our ability to intervene in disease states. Over many years, significant progress has been made in this field, but some obstacles have remained elusive—notably preventing glial encapsulation and electrode degradation. In this review, we discuss the tissue response to electrode implantation on acute and chronic timescales, the electrical changes that occur in electrode systems over time, and strategies that are being investigated in order to minimize the tissue response to implantation and maximize functional electrode longevity. We also highlight the current and future clinical applications and relevance of electrode technology.

scholarly journals Emergent processes in cognitive-emotional interactions

2010 ◽  
Vol 12 (4) ◽  
pp. 433-448 ◽  
Keyword(s):  
Basal Forebrain ◽  
Significant Progress ◽  
Brain Organization ◽  
The Past ◽  
Mind And Brain ◽  
The Mind ◽  
The Brain ◽  
Anatomical Evidence ◽  
Made In

Emotion and cognition have been viewed as largely separate entities in the brain. Within this framework, significant progress has been made in understanding specific aspects of behavior. Research in the past two decades, however, has started to paint a different picture of brain organization, one in which network interactions are key to understanding complex behaviors. From both basic and clinical perspectives, the characterization of cognitive-emotional interactions constitutes a fundamental issue in the investigation of the mind and brain. This review will highlight the interactive and integrative potential that exists in the brain to bring together the cognitive and emotional domains. First, anatomical evidence will be provided, focusing on structures such as hypothalamus, basal forebrain, amygdala, cingulate cortex, orbitofrontal cortex, and insula. Data on functional interactions will then be discussed, followed by a discussion of a dual competition framework, which describes cognitive-emotional interactions in terms of perceptual and cognitive competition mechanisms.

scholarly journals Minimal Tissue Reaction after Chronic Subdural Electrode Implantation for Fully Implantable Brain–Machine Interfaces

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 178
Author(s):  
Tianfang Yan ◽  
Seiji Kameda ◽  
Katsuyoshi Suzuki ◽  
Taro Kaiju ◽  
Masato Inoue ◽  
...  
Keyword(s):  
Tissue Reaction ◽  
Tissue Response ◽  
Brain Machine Interfaces ◽  
Electrode Implantation ◽  
Subdural Electrodes ◽  
Tissue Proliferation ◽  
Significant Difference ◽  
Subdural Electrode ◽  
Cell Densities

There is a growing interest in the use of electrocorticographic (ECoG) signals in brain–machine interfaces (BMIs). However, there is still a lack of studies involving the long-term evaluation of the tissue response related to electrode implantation. Here, we investigated biocompatibility, including chronic tissue response to subdural electrodes and a fully implantable wireless BMI device. We implanted a half-sized fully implantable device with subdural electrodes in six beagles for 6 months. Histological analysis of the surrounding tissues, including the dural membrane and cortices, was performed to evaluate the effects of chronic implantation. Our results showed no adverse events, including infectious signs, throughout the 6-month implantation period. Thick connective tissue proliferation was found in the surrounding tissues in the epidural space and subcutaneous space. Quantitative measures of subdural reactive tissues showed minimal encapsulation between the electrodes and the underlying cortex. Immunohistochemical evaluation showed no significant difference in the cell densities of neurons, astrocytes, and microglia between the implanted sites and contralateral sites. In conclusion, we established a beagle model to evaluate cortical implantable devices. We confirmed that a fully implantable wireless device and subdural electrodes could be stably maintained with sufficient biocompatibility in vivo.

Tissue Compatibility of Silicon Microfabricated Probes Inserted into the Brain

1997 ◽  
Vol 3 (S2) ◽  
pp. 289-290
Author(s):  
J. N. Turner ◽  
William Shain ◽  
D. H. Szarowski ◽  
M. Anderson ◽  
S. Martins ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Single Crystal Silicon ◽  
Tissue Reaction ◽  
Crystal Silicon ◽  
Silicon Oxide Layer ◽  
Disease States ◽  
Large Numbers ◽  
The Central Nervous System ◽  
High Level ◽  
The Brain

The application of nano- and microfabricated devices based on silicon electronics technology is an emerging interdisciplinary area combining engineering and biology. The placement of electrically active probes in damaged or diseased tissues of the central nervous system could have enormous impact on the health and quality of life of large numbers of individuals by restoring lost function, or by treating or controlling disease states. Such probes have been fabricated at a high level of engineering sophistication. Unfortunately, when inserted into the brain a tissue reaction is initiated forming a scar that surrounds and electrically isolates the probe within a few weeks. This reaction is thought to primarily involve glial cells, and is undoubtedly dominated by the bulk surface of the probes which have a silicon oxide layer on top of single crystal silicon.Model probes (Fig. 1) were microfabricated by photolithography with a 1×1mm tab used for gripping and inserting probes.

scholarly journals Investigation of the Feasibility of Ventricular Delivery of Resveratrol to the Microelectrode Tissue Interface

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1446
Author(s):  
Youjoung Kim ◽  
Evon S. Ereifej ◽  
William E. Schwartzman ◽  
Seth M. Meade ◽  
Keying Chen ◽  
...  
Keyword(s):  
Brain Research ◽  
Foreign Body Response ◽  
Tissue Response ◽  
Solubility In Water ◽  
Electrophysiological Recordings ◽  
Drug Elution ◽  
Cellular Debris ◽  
Electrode Interface ◽  
The Brain ◽  
Low Solubility

(1) Background: Intracortical microelectrodes (IMEs) are essential to basic brain research and clinical brain–machine interfacing applications. However, the foreign body response to IMEs results in chronic inflammation and an increase in levels of reactive oxygen and nitrogen species (ROS/RNS). The current study builds on our previous work, by testing a new delivery method of a promising antioxidant as a means of extending intracortical microelectrodes performance. While resveratrol has shown efficacy in improving tissue response, chronic delivery has proven difficult because of its low solubility in water and low bioavailability due to extensive first pass metabolism. (2) Methods: Investigation of an intraventricular delivery of resveratrol in rats was performed herein to circumvent bioavailability hurdles of resveratrol delivery to the brain. (3) Results: Intraventricular delivery of resveratrol in rats delivered resveratrol to the electrode interface. However, intraventricular delivery did not have a significant impact on electrophysiological recordings over the six-week study. Histological findings indicated that rats receiving intraventricular delivery of resveratrol had a decrease of oxidative stress, yet other biomarkers of inflammation were found to be not significantly different from control groups. However, investigation of the bioavailability of resveratrol indicated a decrease in resveratrol accumulation in the brain with time coupled with inconsistent drug elution from the cannulas. Further inspection showed that there may be tissue or cellular debris clogging the cannulas, resulting in variable elution, which may have impacted the results of the study. (4) Conclusions: These results indicate that the intraventricular delivery approach described herein needs further optimization, or may not be well suited for this application.

scholarly journals Integrative activity of the brain in health and disease of the nervous system

2001 ◽  
Vol XXXIII (1-2) ◽  
pp. 75-81
Author(s):  
Yu. N. Bykov
Keyword(s):  
The Body ◽  
Disease States ◽  
Brain Surface ◽  
Humoral Theory ◽  
Franz Joseph Gall ◽  
Health And Disease ◽  
Moral Qualities ◽  
Scientific Worldview ◽  
The Brain ◽  
Made In

Attempts to link human mental and mental activity with the brain were made in the days of Hippocrates (460-370 BC) and Galen (131-201). At the same time, a connection between the brain and movements on the opposite half of the body was noticed. This was judged by the occurrence of seizures in the half of the body opposite to the lesion of the head [44]. The origin of this fact was associated with a general disruption of the brain. The pathogenesis of all disease states was explained by the humoral theory. In accordance with it, the balance of four fluids - phlegm, blood, black and yellow bile - ensures the normal development and activity of the body. When the balance of these components is disturbed, a disease occurs [39]. In the 17th century, Thomas Willis, the author of the term "neurology", somewhat modernized the humoral theory [45]. He believed that general sensitivity is represented in the striatum, his own feelings in the corpus callosum, and memory in the cortex. This marked the beginning of the development of localization as a direction in the study of brain function. At the extreme pole of this scientific worldview is the phrenological teaching of Franz-Joseph Gall and his students [36]. They assumed that mental and moral qualities are localized in certain areas of the brain surface. At the same time, there is a direct relationship between the degree of development of a particular ability and the volume of its cortical representation. By the shape of the skull, its "tubercles" and "bumps, Gall tried to unravel the professional abilities of a person and characterological features. In 1842, Flurance and Haller put forward the thesis of the physiological equivalence of the cortex. The dogma of the equipotentiality of parts of the brain arose, and then the theory of universalism appeared.

Cerebral Tissue Response in Chronic Electrode Implantation

1977 ◽  
Vol 35 ◽  
pp. 624-625
Author(s):  
R.F. Dodson ◽  
L.W-F Chu ◽  
N. Ishihara
Keyword(s):  
Tissue Response ◽  
Whole Body ◽  
Platinum Electrodes ◽  
Fixed Tissue ◽  
Electrode Implantation ◽  
Surface Areas ◽  
Tissue Changes ◽  
Micron Diameter ◽  
Extent Of Damage ◽  
Electrode Sheath

The extent of damage surrounding an implanted electrode in the cerebral cortex is a question of significant importance with regard to attaining consistency and validity of physiological recordings. In order to determine the extent of such tissue changes, 150 micron diameter platinum electrodes were implanted in the cortex of four adult baboons, and after eight days the animals were sacrificed by whole body perfusion with a 3% glutaraldehyde in 0.1M phosphate fixative.The calvarium was carefully removed and the electrode tracts were readily discernible in the firm, glutaraldehyde fixed tissue.Careful dissection of the zone of the electrode tract resulted in a small block which was further sectioned into tip, mid-tract and surface areas. Ultrastructurally, damage extended from the electrode sheath to the greatest extent of from 0.2 to 3.5 mm.

Toward quantitative defect analysis using HREM

1994 ◽  
Vol 52 ◽  
pp. 714-715
Author(s):  
David J. Smith
Keyword(s):  
Electron Microscope ◽  
Unit Cell ◽  
Defect Analysis ◽  
Significant Progress ◽  
Detailed Characterization ◽  
Small Unit ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
Large Unit Cell ◽  
Made In

The electron microscope has evolved to the level where it is now straightforward to record highresolution images from thin samples (t∼10 to 20nm) that are directly interpretable in terms of atomic arrangements. Whilst recorded images necessarily represent two-dimensional projections of the structure, many defects such as dislocations and interfaces may be linear or planar in nature and thus might be expected to be amenable to detailed characterization. In this review, we briefly consider the recent significant progress that has been made in quantitative defect analysis using the high-resolution electron microscope and then discuss some drawbacks to the technique as well as potential scope for further improvements. Surveys of defect modelling for some small-unit-cell materials and interfaces have recently been published, and reference should be made to other papers in this symposium for further examples.The technique of structure imaging originated in the early '70s with observations of large-unit-cell block oxides.

Utility of depth electrode placement in the neurosurgical management of bottom-of-sulcus lesions: technical note

2019 ◽  
Vol 24 (3) ◽  
pp. 284-292
Author(s):  
Eisha A. Christian ◽  
Elysa Widjaja ◽  
Ayako Ochi ◽  
Hiroshi Otsubo ◽  
Stephanie Holowka ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Focal Cortical Dysplasia ◽  
Target Identification ◽  
Cortical Dysplasia ◽  
Technical Note ◽  
Electrode Placement ◽  
Electrode Implantation ◽  
Depth Electrodes ◽  
Intracranial Electrode ◽  
The Brain

OBJECTIVESmall lesions at the depth of the sulcus, such as with bottom-of-sulcus focal cortical dysplasia, are not visible from the surface of the brain and can therefore be technically challenging to resect. In this technical note, the authors describe their method of using depth electrodes as landmarks for the subsequent resection of these exacting lesions.METHODSA retrospective review was performed on pediatric patients who had undergone invasive electroencephalography with depth electrodes that were subsequently used as guides for resection in the period between July 2015 and June 2017.RESULTSTen patients (3–15 years old) met the criteria for this study. At the same time as invasive subdural grid and/or strip insertion, between 2 and 4 depth electrodes were placed using a hand-held frameless neuronavigation technique. Of the total 28 depth electrodes inserted, all were found within the targeted locations on postoperative imaging. There was 1 patient in whom an asymptomatic subarachnoid hemorrhage was demonstrated on postprocedural imaging. Depth electrodes aided in target identification in all 10 cases.CONCLUSIONSDepth electrodes placed at the time of invasive intracranial electrode implantation can be used to help localize, target, and resect primary zones of epileptogenesis caused by bottom-of-sulcus lesions.

Biomarkers for Early Detection of Colitis-associated Colorectal Cancer - Current Concepts, Future Trends

2020 ◽  
Vol 22 (1) ◽  
pp. 137-145
Author(s):  
Tomasz Mackiewicz ◽  
Aleksander Sowa ◽  
Jakub Fichna
Keyword(s):  
Colorectal Cancer ◽  
Early Detection ◽  
Cancer Development ◽  
Sporadic Colorectal Cancer ◽  
Future Trends ◽  
Significant Progress ◽  
Current Standard ◽  
Risk Of Cancer ◽  
Histological Testing ◽  
Made In

: Colitis-associated colorectal cancer (CAC) remains a critical complication of ulcerative colitis (UC) with mortality of approximately 15%, which makes early CAC diagnosis crucial. The current standard of surveillance, with repetitive colonoscopies and histological testing of biopsied mucosa samples is burdensome and expensive, and therefore less invasive methods and reliable biomarkers are needed. Significant progress has been made thanks to continuous extensive research in this field, however no clinically relevant biomarker has been established so far. This review of the current literature presents the genetic and molecular differences between CAC and sporadic colorectal cancer and covers progress made in the early detection of CAC carcinogenesis. It focuses on biomarkers under development, which can be easily tested in samples of body fluids or breath and, once made clinically available, will help to differentiate between progressors (UC patients who will develop dysplasia) from non-progressors and enable early intervention to decrease the risk of cancer development.

scholarly journals H3ABioNet genomic medicine and microbiome data portals hackathon proceedings

Database ◽  
2021 ◽  
Vol 2021 ◽  
Author(s):  
Faisal M Fadlelmola ◽  
Kais Ghedira ◽  
Yosr Hamdi ◽  
Mariem Hanachi ◽  
Fouzia Radouani ◽  
...  
Keyword(s):  
Ethnic Groups ◽  
Genomic Medicine ◽  
Lessons Learned ◽  
Team Work ◽  
Significant Progress ◽  
Team Members ◽  
Pan African ◽  
Scientific Expertise ◽  
Microbiome Data ◽  
Made In

Abstract African genomic medicine and microbiome datasets are usually not well characterized in terms of their origin, making it difficult to find and extract data for specific African ethnic groups or even countries. The Pan-African H3Africa Bioinformatics Network (H3ABioNet) recognized the need for developing data portals for African genomic medicine and African microbiomes to address this and ran a hackathon to initiate their development. The two portals were designed and significant progress was made in their development during the hackathon. All the participants worked in a very synergistic and collaborative atmosphere in order to achieve the hackathon's goals. The participants were divided into content and technical teams and worked over a period of 6 days. In response to one of the survey questions of what the participants liked the most during the hackathon, 55% of the hackathon participants highlighted the familial and friendly atmosphere, the team work and the diversity of team members and their expertise. This paper describes the preparations for the portals hackathon and the interaction between the participants and reflects upon the lessons learned about its impact on successfully developing the two data portals as well as building scientific expertise of younger African researchers. Database URL: The code for developing the two portals was made publicly available in GitHub repositories: [https://github.com/codemeleon/Database; https://github.com/codemeleon/AfricanMicrobiomePortal].

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