scholarly journals Microscale concert hall acoustics to produce uniform ultrasound stimulation for targeted sonogenetics in hsTRPA1-transfected cells

2021 ◽  
Author(s):  
Aditya Vasan ◽  
Florian Allein ◽  
Marc Duque ◽  
Uri Magaram ◽  
Nicholas Boechler ◽  
...  

The field of ultrasound neuromodulation has rapidly developed over the past decade, a consequence of the discovery of strain-sensitive structures in the membrane and organelles of cells extending into the brain, heart, and other organs. Notably, clinical trials are underway for treating epilepsy using focused ultrasound to elicit an organized local electrical response. A key limitation to this approach is the formation of standing waves within the skull. In standing acoustic waves, the maximum ultrasound intensity spatially varies from near zero to double the mean in one half a wavelength, and can lead to localized tissue damage and disruption of normal brain function while attempting to evoke a broader response. This phenomenon also produces a large spatial variation in the actual ultrasound exposure in tissue, leading to heterogeneous results and challenges with interpreting these effects. One approach to overcome this limitation is presented herein: transducer-mounted diffusers that result in spatiotemporally incoherent ultrasound. The signal is numerically and experimentally quantified in an enclosed domain with and without the diffuser. Specifically, we show that adding the diffuser leads to a two-fold increase in ultrasound responsiveness of hsTRPA1 transfected HEK cells. Furthermore, we demonstrate the diffuser allow us to produce an uniform spatial distribution of pressure in the rodent skull. Collectively, we propose that our approach leads to a means to deliver uniform ultrasound into irregular cavities for sonogenetics.

Author(s):  
V. Deepika ◽  
T. Rajasenbagam

A brain tumor is an uncontrolled growth of abnormal brain tissue that can interfere with normal brain function. Although various methods have been developed for brain tumor classification, tumor detection and multiclass classification remain challenging due to the complex characteristics of the brain tumor. Brain tumor detection and classification are one of the most challenging and time-consuming tasks in the processing of medical images. MRI (Magnetic Resonance Imaging) is a visual imaging technique, which provides a information about the soft tissues of the human body, which helps identify the brain tumor. Proper diagnosis can prevent a patient's health to some extent. This paper presents a review of various detection and classification methods for brain tumor classification using image processing techniques.


2006 ◽  
Vol 34 (5) ◽  
pp. 863-867 ◽  
Author(s):  
S. Mizielinska ◽  
S. Greenwood ◽  
C.N. Connolly

Maintaining the correct balance in neuronal activation is of paramount importance to normal brain function. Imbalances due to changes in excitation or inhibition can lead to a variety of disorders ranging from the clinically extreme (e.g. epilepsy) to the more subtle (e.g. anxiety). In the brain, the most common inhibitory synapses are regulated by GABAA (γ-aminobutyric acid type A) receptors, a role commensurate with their importance as therapeutic targets. Remarkably, we still know relatively little about GABAA receptor biogenesis. Receptors are constructed as pentameric ion channels, with α and β subunits being the minimal requirement, and the incorporation of a γ subunit being necessary for benzodiazepine modulation and synaptic targeting. Insights have been provided by the discovery of several specific assembly signals within different GABAA receptor subunits. Moreover, a number of recent studies on GABAA receptor mutations associated with epilepsy have further enhanced our understanding of GABAA receptor biogenesis, structure and function.


2019 ◽  
Vol 8 (3) ◽  
pp. 613-618

Neurochemical transmitters in the brain are fundamental to normal brain function and this investigation aims to introduce a study on the center of neuroscientific through an account of language development which conducts human speech mechanism using theoretical methods. In the process of this work, new understanding has been gained from the neurochemistry of several important neurotransmitters of dopamine (DA), epinephrine (EN), norepinephrine (NE), histamine (HA) and serotonin (ST) in brain by Monte Carlo simulation (MC) which uses the increased temperature to the potential energy of the neurochemicals in the brain considering the geometry optimization of the compounds as an additional conformational level. Moreover, the results of optimized DA, EN, NE, HA, ST neurochemical transmitters by running the physicochemical parameters as a practical model using Gaussian 09 program package can approve the twisting of language-brain due to these structures using density electron deliverers. The most stable of these compounds through the active sites of nitrogen and oxygen atoms has illustrated the best optimized position for localizing the structure through delivery technique in the brain to activate the center of learning a language as a simulated model. So, the best results with the calculated amounts conduct us to analyze the perspective of language learning process and enhancing this ability.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Gilad D Evrony ◽  
Eunjung Lee ◽  
Peter J Park ◽  
Christopher A Walsh

Whether somatic mutations contribute functional diversity to brain cells is a long-standing question. Single-neuron genomics enables direct measurement of somatic mutation rates in human brain and promises to answer this question. A recent study (<xref ref-type="bibr" rid="bib65">Upton et al., 2015</xref>) reported high rates of somatic LINE-1 element (L1) retrotransposition in the hippocampus and cerebral cortex that would have major implications for normal brain function, and suggested that these events preferentially impact genes important for neuronal function. We identify aspects of the single-cell sequencing approach, bioinformatic analysis, and validation methods that led to thousands of artifacts being interpreted as somatic mutation events. Our reanalysis supports a mutation frequency of approximately 0.2 events per cell, which is about fifty-fold lower than reported, confirming that L1 elements mobilize in some human neurons but indicating that L1 mosaicism is not ubiquitous. Through consideration of the challenges identified, we provide a foundation and framework for designing single-cell genomics studies.


2000 ◽  
Vol 12 (1-2) ◽  
pp. 53-67 ◽  
Author(s):  
Daniela Montaldi ◽  
Andrew R. Mayes

The last ten years have seen the development and expansion of an exciting new field of neuroscientific research; functional mapping of the human brain. Whilst many of the questions addressed by this area of research could be answered using SPECT, relatively few SPECT activation studies of this kind have been carried out. The present paper combines an evaluation of SPECT procedures used for neuroactivation studies, and their comparison with other imaging modalities (i.e., PET and fMRI), with a review of SPECT neuroactivation studies that yield information concerning normal brain function with a particular emphasis on the brain activations produced by memory processing. The paper aims to describe and counter common misunderstandings regarding potential limitations of the SPECT technique, to explain and illustrate which SPECT procedures best fulfill the requirements of a neuroactivation study, and how best to obtain information about normal brain function (whether using normal healthy subjects or patients) and finally to highlight SPECT’s potential future role in the functional mapping of the human brain.


2015 ◽  
Vol 16 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Dragan M. Pavlović ◽  
Merdin Š. Markišić ◽  
Aleksandra M. Pavlović

Abstract Vitamins are necessary factors in human development and normal brain function. Vitamin C is a hydrosoluble compound that humans cannot produce; therefore, we are completely dependent on food intake for vitamin C. Ascorbic acid is an important antioxidative agent and is present in high concentrations in neurons and is also crucial for collagen synthesis throughout the body. Ascorbic acid has a role in modulating many essential neurotransmitters, enables neurogenesis in adult brain and protects cells against infection. While SVCT1 enables the absorption of vitamin C in the intestine, SVCT2 is primarily located in the brain. Ascorbate deficiency is classically expressed as scurvy, which is lethal if not treated. However, subclinical deficiencies are probably much more frequent. Potential fields of vitamin C therapy are in neurodegenerative, cerebrovascular and affective diseases, cancer, brain trauma and others. For example, there is some data on its positive effects in Alzheimer’s disease. Various dosing regimes are used, but ascorbate is safe, even in high doses for protracted periods. Better designed studies are needed to elucidate all of the potential therapeutic roles of vitamin C.


2021 ◽  
Vol 15 ◽  
Author(s):  
Mahmoud Salami

The human gastrointestinal tract hosts trillions of microorganisms that is called “gut microbiota.” The gut microbiota is involved in a wide variety of physiological features and functions of the body. Thus, it is not surprising that any damage to the gut microbiota is associated with disorders in different body systems. Probiotics, defined as living microorganisms with health benefits for the host, can support or restore the composition of the gut microbiota. Numerous investigations have proved a relationship between the gut microbiota with normal brain function as well as many brain diseases, in which cognitive dysfunction is a common clinical problem. On the other hand, increasing evidence suggests that the existence of a healthy gut microbiota is crucial for normal cognitive processing. In this regard, interplay of the gut microbiota and cognition has been under focus of recent researches. In the present paper, I review findings of the studies considering beneficial effects of either gut microbiota or probiotic bacteria on the brain cognitive function in the healthy and disease statuses.


2021 ◽  
Vol 15 ◽  
Author(s):  
Hannah C. Bennett ◽  
Yongsoo Kim

The pericyte is a perivascular cell type that encapsulates the microvasculature of the brain and spinal cord. Pericytes play a crucial role in the development and maintenance of the blood-brain barrier (BBB) and have a multitude of important functions in the brain. Recent evidence indicates that pericyte impairment has been implicated in neurovascular pathology associated with various human diseases such as diabetes mellitus, Alzheimer’s disease (AD), and stroke. Although the pericyte is essential for normal brain function, knowledge about its developmental trajectory and anatomical distribution is limited. This review article summarizes the scientific community’s current understanding of pericytes’ regional heterogeneity in the brain and their changes during major life stages. More specifically, this review article focuses on pericyte differentiation and migration during brain development, regional population differences in the adult brain, and changes during normal and pathological aging. Most of what is known about pericytes come from studies of the cerebral cortex and hippocampus. Therefore, we highlight the need to expand our understanding of pericyte distribution and function in the whole brain to better delineate this cell type’s role in the normal brain and pathological conditions.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1245
Author(s):  
Marie-Solenne Felix ◽  
Emilie Borloz ◽  
Khaled Metwally ◽  
Ambre Dauba ◽  
Benoit Larrat ◽  
...  

Gene therapy represents a powerful therapeutic tool to treat diseased tissues and provide a durable and effective correction. The central nervous system (CNS) is the target of many gene therapy protocols, but its high complexity makes it one of the most difficult organs to reach, in part due to the blood-brain barrier that protects it from external threats. Focused ultrasound (FUS) coupled with microbubbles appears as a technological breakthrough to deliver therapeutic agents into the CNS. While most studies focus on a specific targeted area of the brain, the present work proposes to permeabilize the entire brain for gene therapy in several pathologies. Our results show that, after i.v. administration and FUS sonication in a raster scan manner, a self-complementary AAV9-CMV-GFP vector strongly and safely infected the whole brain of mice. An increase in vector DNA (19.8 times), GFP mRNA (16.4 times), and GFP protein levels (17.4 times) was measured in whole brain extracts of FUS-treated GFP injected mice compared to non-FUS GFP injected mice. In addition to this increase in GFP levels, on average, a 7.3-fold increase of infected cells in the cortex, hippocampus, and striatum was observed. No side effects were detected in the brain of treated mice. The combining of FUS and AAV-based gene delivery represents a significant improvement in the treatment of neurological genetic diseases.


Author(s):  
Bruce R. Ransom

This resource is the long-awaited new revision of the most highly regarded reference volume on glial cells, and has been completely revised, greatly enlarged, and enhanced with full color figures throughout. Neglected in research for years, it is now evident that the brain only functions in a concerted action of all the cells, namely glia and neurons. Seventy one chapters comprehensively discuss virtually every aspect of normal glial cell anatomy, physiology, biochemistry and function, and consider the central roles of these cells in neurological diseases including stroke, Alzheimer disease, multiple sclerosis, Parkinson's disease, neuropathy, and psychiatric conditions. With more than 20 new chapters it addresses the massive growth of knowledge about the basic biology of glia and the sophisticated manner in which they partner with neurons in the course of normal brain function.


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