Burster Reconstruction Considering Unmeasurable Variables in the Epileptor Model

2021 ◽  
pp. 1-46
Author(s):  
João Angelo Ferres Brogin ◽  
Jean Faber ◽  
Douglas Domingues Bueno

Abstract Epilepsy is one of the most common brain disorders worldwide, affecting millions of people every year. Although significant effort has been put into better understanding it and mitigating its effects, the conventional treatments are not fully effective. Advances in computational neuroscience, using mathematical dynamic models that represent brain activities at different scales, have enabled addressing epilepsy from a more theoretical standpoint. In particular, the recently proposed Epileptor model stands out among these models, because it represents well the main features of seizures, and the results from its simulations have been consistent with experimental observations. In addition, there has been an increasing interest in designing control techniques for Epileptor that might lead to possible realistic feedback controllers in the future. However, such approaches rely on knowing all of the states of the model, which is not the case in practice. The work explored in this letter aims to develop a state observer to estimate Epileptor's unmeasurable variables, as well as reconstruct the respective so-called bursters. Furthermore, an alternative modeling is presented for enhancing the convergence speed of an observer. The results show that the proposed approach is efficient under two main conditions: when the brain is undergoing a seizure and when a transition from the healthy to the epileptiform activity occurs.

Author(s):  
Joel Z. Leibo ◽  
Tomaso Poggio

This chapter provides an overview of biological perceptual systems and their underlying computational principles focusing on the sensory sheets of the retina and cochlea and exploring how complex feature detection emerges by combining simple feature detectors in a hierarchical fashion. We also explore how the microcircuits of the neocortex implement such schemes pointing out similarities to progress in the field of machine vision driven deep learning algorithms. We see signs that engineered systems are catching up with the brain. For example, vision-based pedestrian detection systems are now accurate enough to be installed as safety devices in (for now) human-driven vehicles and the speech recognition systems embedded in smartphones have become increasingly impressive. While not being entirely biologically based, we note that computational neuroscience, as described in this chapter, makes up a considerable portion of such systems’ intellectual pedigree.


Author(s):  
Saleh A Othman ◽  

Background: Blood flow to the brain is in parallel with brain metabolism in almost all brain disorders except in brain tumors and therefore regional cerebral blood flow can be used as a marker of metabolic brain activity and hence it is closely linked to neuronal activity, the activity distribution is presumed to reflect neuronal activity levels in different areas of the brain. Purpose: The aim of this work is to demonstrate to pediatrician in general and pediatric neurologist in particular the variations in cerebral perfusion during normal development which should be taken into consideration at the time of interpreting SPECT brain perfusion scan in different pediatric brain disorders. Method: Brain SPECT was performed 10 minutes after an intravenous injection of 11.1 MBq/kg (0.3 mCi/kg), and the minimum dose is 185 MBq (5 mCi) of 99mTc-HMPAO (4). Results: This was a retrospective analysis of SPECT brain perfusion scan of pediatric patients performed between October 2015 and December 2019 at our institution. We selected normal and abnormal studies in pediatric population with age range (5 months - 14 years). Conclusion: Although anatomic cross sectional imaging give details of neurological structural changes, SPECT perfusion mirrors indirectly both metabolic and neuronal activity changes. Therefore, accurate interpretation of SPECT perfusion will consolidate its role as part of the diagnostic protocol and used when the findings of other imaging modalities do not explain the symptoms or fail partially or completely in determining the etiology of brain disorders in pediatric patients.


2015 ◽  
Vol 5 (1) ◽  
pp. 739-747 ◽  
Author(s):  
I. Ahmad ◽  
A. Saaban ◽  
A. Ibrahin ◽  
M. Shahzad

The problem of chaos synchronization is to design a coupling between two chaotic systems (master-slave/drive-response systems configuration) such that the chaotic time evaluation becomes ideal and the output of the slave (response) system asymptotically follows the output of the master (drive) system. This paper has addressed the chaos synchronization problem of two chaotic systems using the Nonlinear Control Techniques, based on Lyapunov stability theory. It has been shown that the proposed schemes have outstanding transient performances and that analytically as well as graphically, synchronization is asymptotically globally stable. Suitable feedback controllers are designed to stabilize the closed-loop system at the origin. All simulation results are carried out to corroborate the effectiveness of the proposed methodologies by using Mathematica 9.


2022 ◽  
Author(s):  
Zhen-Ge Luo ◽  
Xin-Yao Sun ◽  
Xiang-Chun Ju ◽  
Yang Li ◽  
Peng-Ming Zeng ◽  
...  

The recently developed brain organoids have been used to recapitulate the processes of brain development and related diseases. However, the lack of vasculatures, which regulate neurogenesis, brain disorders, and aging process, limits the utility of brain organoids. In this study, we induced vessel and brain organoids respectively, and then fused two types of organoids together to obtain vascularized brain organoids. The fused brain organoids were engrafted with robust vascular network-like structures, and exhibited increased number of neural progenitors, in line with the possibility that vessels regulate neural development. Fusion organoids also contained functional blood-brain-barrier (BBB)-like structures, as well as microglial cells, a specific population of immune cells in the brain. The incorporated microglia responded actively to immune stimuli to the fused brain organoids. Thus, the fusion organoids established in this study allow modeling interactions between the neuronal and non-neuronal components in vitro, in particular the vasculature and microglia niche.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1702
Author(s):  
Sereen Sandouka ◽  
Tawfeeq Shekh-Ahmad

Epilepsy is a chronic disease of the brain that affects over 65 million people worldwide. Acquired epilepsy is initiated by neurological insults, such as status epilepticus, which can result in the generation of ROS and induction of oxidative stress. Suppressing oxidative stress by upregulation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown to be an effective strategy to increase endogenous antioxidant defences, including in brain diseases, and can ameliorate neuronal damage and seizure occurrence in epilepsy. Here, we aim to test the neuroprotective potential of a naturally occurring Nrf2 activator sulforaphane, in in vitro epileptiform activity model and a temporal lobe epilepsy rat model. Sulforaphane significantly decreased ROS generation during epileptiform activity, restored glutathione levels, and prevented seizure-like activity-induced neuronal cell death. When given to rats after 2 h of kainic acid-induced status epilepticus, sulforaphane significantly increased the expression of Nrf2 and related antioxidant genes, improved oxidative stress markers, and increased the total antioxidant capacity in both the plasma and hippocampus. In addition, sulforaphane significantly decreased status epilepticus-induced neuronal cell death. Our results demonstrate that Nrf2 activation following an insult to the brain exerts a neuroprotective effect by reducing neuronal death, increasing the antioxidant capacity, and thus may also modify epilepsy development.


2021 ◽  
Vol 14 (2) ◽  
pp. e236963
Author(s):  
Alex Stoyanov ◽  
Alan McDougall ◽  
Nicolas Urriola

IgLON5 antibodies are typically associated with the insidious onset of sleep disorder, parasomnia, gait disturbance and abnormal movements, with variable response to immunosuppressive therapy. We describe a case of a 50-year-old man who presented with acute speech difficulties, headache and focal seizures followed by well-formed visual hallucinations, and later, musical hallucinations of mainstream popular music. MRI of the brain demonstrated right temporal lobe changes with corresponding epileptiform activity seen on electroencephalogram. Subsequently, IgLON5 antibodies were detected in the serum. The patient was treated with anticonvulsants, as well as azathioprine with a tapering oral prednisone course with a complete resolution of the symptoms. Our case demonstrates an unusual presentation of the rare but increasingly described anti-IgLON5 disease, with musical hallucinations. The case highlights the variable and evolving clinical phenotypes that can be seen in autoimmune central nervous system disorders.


PEDIATRICS ◽  
1996 ◽  
Vol 97 (6) ◽  
pp. 924-926
Author(s):  
Ramin Alemzadeh ◽  
Karsten Gammeltoft ◽  
Karla Matteson

Nonketotic hyperglycinemia (NKH) is an inborn error of glycine degradation causing muscular hypotonia, seizures, apnea, and lethargy; it has a poor prognosis. Accumulation of glycine in the brain is thought to cause excessive stimulation of the N-methyl-D-aspartate receptor. Dextromethorphan (DM), an N-methyl-D-aspartate receptor antagonist, in doses of 5 to 35 mg/kg per day has been shown to have beneficial therapeutic effects in some patients with NKH. We report the case of a 1-year-old infant with NKH, seizure disorder, and psychomotor delay who was clinically seizure free during treatment with sodium benzoate, arginine, benzodiazepam, and phenobarbital. Although sodium benzoate normalized serum glycine levels (103 to 125 µmol/L), cerebrospinal fluid glycine levels remained elevated (42 to 47 µmol/L), with epileptiform activity on electroencephalography. The addition of low-dose DM (0.25 mg/kg per day) to the treatment led to improvement of electroencephalographic activity, resolution of nystagmus with increased eye contact, and modest progression of developmental milestones. These data suggest that DM at doses significantly lower than previously reported may be beneficial in some patients with NKH. Treatment with low-dose DM needs further evaluation.


2018 ◽  
Vol 40 (5-6) ◽  
pp. 382-395 ◽  
Author(s):  
Leslie Magtanong ◽  
Scott J. Dixon

Ferroptosis is a nonapoptotic form of cell death characterized by the iron-dependent accumulation of toxic lipid reactive oxygen species. Small-molecule screening and subsequent optimization have yielded potent and specific activators and inhibitors of this process. These compounds have been employed to dissect the lethal mechanism and implicate this process in pathological cell death events observed in many tissues, including the brain. Indeed, ferroptosis is emerging as an important mechanism of cell death during stroke, intracerebral hemorrhage, and other acute brain injuries, and may also play a role in certain degenerative brain disorders. Outstanding issues include the practical need to identify molecular markers of ferroptosis that can be used to detect and study this process in vivo, and the more basic problem of understanding the relationship between ferroptosis and other forms of cell death that can be triggered in the brain during injury.


2014 ◽  
Vol 4 (3) ◽  
pp. 60 ◽  
Author(s):  
Chiu Choi

this paper is a result of the implementation of the recommendations on enhancing hands-on experience of control engineering education using single chip, small scale computers such as microcontrollers. A set of microcontroller-based feedback control experiments was developed for the Electrical Engineering curriculum at the University of North Florida. These experiments provided hands-on techniques that students can utilize in the development of complete solutions for a number of servo control problems. Significant effort was devoted to software development of feedback controllers and the associated signal conditioning circuits interfacing between the microcontroller and the physical plant. These experiments have stimulated the interest of our students in control engineering.


Author(s):  
Rosa Delgado Jiménez ◽  
Corinne Benakis

AbstractThe intestinal microbiome is emerging as a critical factor in health and disease. The microbes, although spatially restricted to the gut, are communicating and modulating the function of distant organs such as the brain. Stroke and other neurological disorders are associated with a disrupted microbiota. In turn, stroke-induced dysbiosis has a major impact on the disease outcome by modulating the immune response. In this review, we present current knowledge on the role of the gut microbiome in stroke, one of the most devastating brain disorders worldwide with very limited therapeutic options, and we discuss novel insights into the gut-immune-brain axis after an ischemic insult. Understanding the nature of the gut bacteria-brain crosstalk may lead to microbiome-based therapeutic approaches that can improve patient recovery.


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