scholarly journals A Review of Microelectronic Systems and Circuit Techniques for Electrical Neural Recording Aimed at Closed-Loop Epilepsy Control

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5716
Author(s):  
Reza Ranjandish ◽  
Alexandre Schmid

Closed-loop implantable electronics offer a new trend in therapeutic systems aimed at controlling some neurological diseases such as epilepsy. Seizures are detected and electrical stimulation applied to the brain or groups of nerves. To this aim, the signal recording chain must be very carefully designed so as to operate in low-power and low-latency, while enhancing the probability of correct event detection. This paper reviews the electrical characteristics of the target brain signals pertaining to epilepsy detection. Commercial systems are presented and discussed. Finally, the major blocks of the signal acquisition chain are presented with a focus on the circuit architecture and a careful attention to solutions to issues related to data acquisition from multi-channel arrays of cortical sensors.

2021 ◽  
Vol 39 (7) ◽  
pp. 1117-1132
Author(s):  
Samaa S. Abdulwahab ◽  
Hussain K. Khleaf ◽  
Manal H. Jassim

A Brain-Computer Interface (BCI) is an external system that controls activities and processes in the physical world based on brain signals. In Passive BCI, artificial signals are automatically generated by a computer program without any input from nerves in the body. This is useful for individuals with mobility issues. Traditional BCI has been dependent only on recording brain signals with Electroencephalograph (EEG) and has used a rule-based translation algorithm to generate control commands. These systems have developed very accurate translation systems. This paper is about the different methods for adapting the signals from the brain. It has been mentioned that various kinds of surveys in the past to serve the purpose of the present research. This paper shows a simple and easy analysis of each technique and its respective benefits and drawbacks, including signal acquisition, signal pre-processing, feature classification and classification. Finally,  discussed is the application of EEG-based BCI.


2021 ◽  
Author(s):  
Adele Fanelli ◽  
Laura Ferlauto ◽  
Elodie Geneviève Zollinger ◽  
Olivier Brina ◽  
Philippe Reymond ◽  
...  

AbstractNeural recording and stimulation have been widely used to mitigate traumatic injuries, neurodegenerative diseases or mental disorders. Most neural interfaces commonly require invasive surgery, potentially entailing both transient and permanent complications. A promising strategy designed to overcome these risks involves exploiting the cerebrovascular system as an access route to the neural tissue. Here we present a novel endovascular neural interface for neural recording and stimulation, fully polymeric and degradable. This concept might allow for better integration of the device in the body, reduced inflammatory reaction, the possibility of replacing the implant after degradation, and avoiding removal surgeries. The vasculature’s strategic distribution and the use of soft polymers for the device’s fabrication will permit targeting both the brain vasculature and the peripheral system. Therefore, this novel endovascular neural interface will broaden the range of applications from neurological diseases and mental disorders to bioelectronics medicine.


Author(s):  
Selma Büyükgöze

Brain Computer Interface consists of hardware and software that convert brain signals into action. It changes the nerves, muscles, and movements they produce with electro-physiological signs. The BCI cannot read the brain and decipher the thought in general. The BCI can only identify and classify specific patterns of activity in ongoing brain signals associated with specific tasks or events. EEG is the most commonly used non-invasive BCI method as it can be obtained easily compared to other methods. In this study; It will be given how EEG signals are obtained from the scalp, with which waves these frequencies are named and in which brain states these waves occur. 10-20 electrode placement plan for EEG to be placed on the scalp will be shown.


2021 ◽  
Vol 7 (22) ◽  
pp. eabg3362
Author(s):  
Hamidreza Shaye ◽  
Benjamin Stauch ◽  
Cornelius Gati ◽  
Vadim Cherezov

Metabotropic γ-aminobutyric acid G protein–coupled receptors (GABAB) represent one of the two main types of inhibitory neurotransmitter receptors in the brain. These receptors act both pre- and postsynaptically by modulating the transmission of neuronal signals and are involved in a range of neurological diseases, from alcohol addiction to epilepsy. A series of recent cryo-EM studies revealed critical details of the activation mechanism of GABAB. Structures are now available for the receptor bound to ligands with different modes of action, including antagonists, agonists, and positive allosteric modulators, and captured in different conformational states from the inactive apo to the fully active state bound to a G protein. These discoveries provide comprehensive insights into the activation of the GABAB receptor, which not only broaden our understanding of its structure, pharmacology, and physiological effects but also will ultimately facilitate the discovery of new therapeutic drugs and neuromodulators.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 717
Author(s):  
Ilenia Savinetti ◽  
Angela Papagna ◽  
Maria Foti

Monocytes play a crucial role in immunity and tissue homeostasis. They constitute the first line of defense during the inflammatory process, playing a role in the pathogenesis and progression of diseases, making them an attractive therapeutic target. They are heterogeneous in morphology and surface marker expression, which suggest different molecular and physiological properties. Recent evidences have demonstrated their ability to enter the brain, and, as a consequence, their hypothetical role in different neurodegenerative diseases. In this review, we will discuss the current knowledge about the correlation between monocyte dysregulation in the brain and/or in the periphery and neurological diseases in humans. Here we will focus on the most common neurodegenerative disorders, such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis and multiple sclerosis.


Author(s):  
Diane Moujalled ◽  
Andreas Strasser ◽  
Jeffrey R. Liddell

AbstractTightly orchestrated programmed cell death (PCD) signalling events occur during normal neuronal development in a spatially and temporally restricted manner to establish the neural architecture and shaping the CNS. Abnormalities in PCD signalling cascades, such as apoptosis, necroptosis, pyroptosis, ferroptosis, and cell death associated with autophagy as well as in unprogrammed necrosis can be observed in the pathogenesis of various neurological diseases. These cell deaths can be activated in response to various forms of cellular stress (exerted by intracellular or extracellular stimuli) and inflammatory processes. Aberrant activation of PCD pathways is a common feature in neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, resulting in unwanted loss of neuronal cells and function. Conversely, inactivation of PCD is thought to contribute to the development of brain cancers and to impact their response to therapy. For many neurodegenerative diseases and brain cancers current treatment strategies have only modest effect, engendering the need for investigations into the origins of these diseases. With many diseases of the brain displaying aberrations in PCD pathways, it appears that agents that can either inhibit or induce PCD may be critical components of future therapeutic strategies. The development of such therapies will have to be guided by preclinical studies in animal models that faithfully mimic the human disease. In this review, we briefly describe PCD and unprogrammed cell death processes and the roles they play in contributing to neurodegenerative diseases or tumorigenesis in the brain. We also discuss the interplay between distinct cell death signalling cascades and disease pathogenesis and describe pharmacological agents targeting key players in the cell death signalling pathways that have progressed through to clinical trials.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Kohei Segawa ◽  
Yukari Blumenthal ◽  
Yuki Yamawaki ◽  
Gen Ohtsuki

The lymphatic system is important for antigen presentation and immune surveillance. The lymphatic system in the brain was originally introduced by Giovanni Mascagni in 1787, while the rediscovery of it by Jonathan Kipnis and Kari Kustaa Alitalo now opens the door for a new interpretation of neurological diseases and therapeutic applications. The glymphatic system for the exchanges of cerebrospinal fluid (CSF) and interstitial fluid (ISF) is associated with the blood-brain barrier (BBB), which is involved in the maintenance of immune privilege and homeostasis in the brain. Recent notions from studies of postmortem brains and clinical studies of neurodegenerative diseases, infection, and cerebral hemorrhage, implied that the breakdown of those barrier systems and infiltration of activated immune cells disrupt the function of both neurons and glia in the parenchyma (e.g., modulation of neurophysiological properties and maturation of myelination), which causes the abnormality in the functional connectivity of the entire brain network. Due to the vulnerability, such dysfunction may occur in developing brains as well as in senile or neurodegenerative diseases and may raise the risk of emergence of psychosis symptoms. Here, we introduce this hypothesis with a series of studies and cellular mechanisms.


2021 ◽  
Author(s):  
Marzia Soligo ◽  
Fausto Maria Felsani ◽  
Tatiana Da Ros ◽  
Susanna Bosi ◽  
Elena Pellizzoni ◽  
...  

Carbon nanotubes (CNTs) are currently under active investigation for their use in several biomedical applications, especially in neurological diseases and nervous system injury due to their electrochemical properties.


2017 ◽  
Vol 5 (13) ◽  
pp. 2445-2458 ◽  
Author(s):  
I. Mitch Taylor ◽  
Zhanhong Du ◽  
Emma T. Bigelow ◽  
James R. Eles ◽  
Anthony R. Horner ◽  
...  

First everin vivosensor for directly measuring cocaine concentration in the brainviaelectrochemical detection at DNA aptamer functionalized single shank, silicon-based neural recording probes.


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