Astroglial contribution to tau-dependent neurodegeneration

2019 ◽  
Vol 476 (22) ◽  
pp. 3493-3504 ◽  
Author(s):  
Marta Sidoryk-Węgrzynowicz ◽  
Lidia Strużyńska
Keyword(s):  
Nervous System ◽  
Synaptic Transmission ◽  
Neurofibrillary Tangles ◽  
Neuronal Survival ◽  
Critical Role ◽  
Proper Function ◽  
Neuronal Dysfunction ◽  
Neuronal Function ◽  
Glutamate Homeostasis ◽  
The Brain

Astrocytes, by maintaining an optimal environment for neuronal function, play a critical role in proper function of mammalian nervous system. They regulate synaptic transmission and plasticity and protect neurons against toxic insults. Astrocytes and neurons interact actively via glutamine-glutamate cycle (GGC) that supports neuronal metabolic demands and neurotransmission. GGC deficiency may be involved in different diseases of the brain, where impaired astrocytic control of glutamate homeostasis contributes to neuronal dysfunction. This includes tau-dependent neurodegeneration, where astrocytes lose key molecules involved in regulation of glutamate/glutamine homeostasis, neuronal survival and synaptogenesis. Astrocytic dysfunction in tauopathy appears to precede neurodegeneration and overt tau neuropathology such as phosphorylation, aggregation and formation of neurofibrillary tangles. In this review, we summarize recent studies demonstrating that activation of astrocytes is strictly associated with neurodegenerative processes including those involved in tau related pathology. We propose that astrocytic dysfunction, by disrupting the proper neuron-glia signalling early in the disease, significantly contributes to tauopathy pathogenesis.

Kirlian Experimental Analysis and IoT

2021 ◽  
Vol 10 (2) ◽  
pp. 29-43
Author(s):  
Rohit Rastogi ◽  
Mamta Saxena ◽  
Devendra K. Chaturvedi ◽  
Mayank Gupta ◽  
Akshit Rajan Rastogi ◽  
...  
Keyword(s):  
Nervous System ◽  
Energy Levels ◽  
Critical Role ◽  
The Body ◽  
Extensive Literature ◽  
Entire Body ◽  
Body Parts ◽  
Sodium Potassium ◽  
Charged Ions ◽  
The Brain

Our entire body, including the brain and nervous system, works with the help of various kinds of biological stuff which includes positively charged ions of elements like sodium, potassium, and calcium. The different body parts have different energy levels, and by measuring the energy level, we can also measure the fitness of an individual. Moreover, this energy and fitness are directly related to mental health and the signals being transmitted between the brain and other parts of the body. Various activities like walking, talking, eating, and thinking are performed with the help of these transmission signals. Another critical role played by them is that it helps in examining the mechanisms of cells present at various places in the human body and signaling the nervous system and brain if they are properly functioning or not. This manuscript is divided into two parts where, in the first part, it provides the introduction, background, and extensive literature survey on Kirlian experiments to measure the human's organ energy.

scholarly journals Stochastic, structural and functional factors influencing AMPA and NMDA synaptic response variability: a review

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Vito Di Maio ◽  
Francesco Ventriglia ◽  
Silvia Santillo
Keyword(s):  
Nervous System ◽  
Synaptic Transmission ◽  
Learning And Memory ◽  
Information Transfer ◽  
Basic Mechanism ◽  
Response Variability ◽  
Synaptic Response ◽  
Factors Influencing ◽  
Functional Factors ◽  
The Brain

Synaptic transmission is the basic mechanism of information transfer between neurons not only in the brain, but along all the nervous system. In this review we will briefly summarize some of the main parameters that produce stochastic variability in the synaptic response. This variability produces different effects on important brain phenomena, like learning and memory, and, alterations of its basic factors can cause brain malfunctioning.

scholarly journals The ATF6β-calreticulin axis promotes neuronal survival under endoplasmic reticulum stress and excitotoxicity

2021 ◽  
Author(s):  
Dinh Thi Nguyen ◽  
Thuong Manh Le ◽  
Tsuyoshi Hattori ◽  
Mika Takarada-Iemata ◽  
Hiroshi Ishii ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Hippocampal Neurons ◽  
Neuronal Survival ◽  
Binding Capacity ◽  
Critical Role ◽  
Er Stress Response ◽  
The Central Nervous System ◽  
The Brain

AbstractWhile ATF6α plays a central role in the endoplasmic reticulum (ER) stress response, the function of ATF6β is largely unknown. Here, we demonstrate that ATF6β is highly expressed in the hippocampus of the brain, and specifically regulates the expression of calreticulin, a molecular chaperone in the ER with a high Ca2+-binding capacity. Calreticulin expression was reduced to ~50% in the central nervous system of Atf6b−/− mice, and restored by ATF6β. Analysis using cultured hippocampal neurons revealed that ATF6β deficiency reduced Ca2+ stores in the ER and enhanced ER stress-induced death, which was rescued by ATF6β, calreticulin, Ca2+-modulating reagents such as BAPTA-AM and 2-APB, and ER stress inhibitor salubrinal. In vivo, kainate-induced neuronal death was enhanced in hippocampi of Atf6b−/− and Calr+/− mice, and restored by 2-APB and salubrinal. These results suggest that the ATF6β-calreticulin axis plays a critical role in the neuronal survival by improving Ca2+ homeostasis under ER stress.

scholarly journals Glymphatics: A Transformative Development in Medical Neuroscience Relevant to Injuries in Military Central Nervous System

2021 ◽  
Author(s):  
James Meyerhoff ◽  
Nabarun Chakraborty ◽  
Rasha Hammamieh
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sleep Deprivation ◽  
Brain Edema ◽  
Critical Role ◽  
Spatial Relationship ◽  
Military Operations ◽  
Glymphatic System ◽  
The Brain

ABSTRACT Introduction The glia-operated glymphatic system, analogous to but separate from the lymphatics in the periphery, is unique to brain and retina, where it is very closely aligned with the arteriolar system. This intimate relationship leads to a “blood vessel like” distribution pattern of glymphatic vessels in the brain. The spatial relationship of glymphatics, including their essential component aquaporin-4 with vascular pericytes of brain arterioles is critical to functionality and is termed “polarization”. Materials and Methods We review the available literature on the factors affecting the resting state of glymphatics under normal conditions, including the important role of sleep in supporting normal glymphatic function (including waste removal) as well as the critical role of “polarization” under normal conditions. We then examine the effects of traumatic brain injury (TBI) or seizures on the glymphatic system and its state of “polarization”. Results Injury, such as TBI, can disrupt polarization resulting in “depolarization” leading to brain edema. Conclusion Damage to the glymphatic system might explain the brain edema so often seen following TBI or other insult. Moreover, similar damage should be expected in response to seizures, which can often be associated with chemical exposures as well as with TBI. Military operations, whether night operations or continuous operations, quite often impose limitations on sleep. As glymphatic function is sleep-dependent, sleep deprivation alone could compromise glymphatic function, as well, and might in addition, explain some of the well-known performance deficits associated with sleep deprivation. Possible effects of submarine and diving operations, chemical agents (including seizures), as well as high altitude exposure and other threats should be considered. In addition to the brain, the retina is also served and protected by the glymphatic system. Accordingly, the effect of military-related risks (e.g., exposure to laser or other threats) to retinal glymphatic function should also be considered. An intact glymphatic system is absolutely essential to support normal central nervous system functionality, including cognition. This effects a broad range of military threats on brain and retinal glymphatics should be explored. Possible preventive and therapeutic measures should be proposed and evaluated, as well.

Cells of the Nervous System

2017 ◽  
Author(s):  
Peggy Mason
Keyword(s):  
Nervous System ◽  
Axonal Transport ◽  
Information Transfer ◽  
Common Mechanism ◽  
Neuronal Function ◽  
Synaptic Terminals ◽  
System P ◽  
Paraneoplastic Disease ◽  
Mature Neurons ◽  
The Brain

The nervous system is made up of neurons and glia that derive from neuroectoderm. Since neurons are terminally differentiated and do not divide, primary intracranial tumors do not arise from mature neurons. Tumors outside the nervous system may metastasize inside the brain or may release a substance that negatively affects brain function, termed paraneoplastic disease. Neurons receive information through synaptic inputs onto dendrites and soma and send information to other cells via a synaptic terminal. Most neurons send information to faraway locations and for this, an axon that connects the soma to synaptic terminals is required. Glial cells wrap axons in myelin, which speeds up information transfer. Axonal transport is necessary to maintain neuronal function and health across the long distances separating synaptic terminals and somata. A common mechanism of neurodegeneration arises from impairments in axonal transport that lead to protein aggregation and neuronal death.

The tracheal supply to the central nervous system of the locust

1980 ◽  
Vol 207 (1166) ◽  
pp. 63-78 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Transmission ◽  
Gaseous Exchange ◽  
Optic Lobes ◽  
Cortical Areas ◽  
Cobalt Sulphide ◽  
The Central Nervous System ◽  
The Brain

The tracheal supply to the central nervous system of the locust has been revealed by staining with cobalt sulphide. Air that enters through the first pair of thoracic spiracles is carried first to the brain and then to the rest of the central nervous system. The air is expelled through the abdominal spiracles, so that there is a one-way circulation with diffusional exchange only in the blindly ending tracheae that enter the brain or ganglia. Once inside a ganglion, the tracheae branch profusely to end in a mass of fine tracheoles through which gaseous exchange takes place. The densest tracheation is in the neuropile areas, where the spacing between tracheoles is about 17 μm. In the optic lobes, where there is order to the synaptic arrangement of a neuropile, there is a matching orderliness of the tracheation. Cortical areas, which contain the cell bodies of neurons, have only a sparse tracheation. It may be concluded that it is the processes associated with synaptic transmission that require the most immediate access to the sites of gaseous exchange.

scholarly journals Lighting Up Ca2+ Dynamics in Animal Models

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2133
Author(s):  
Nelly Redolfi ◽  
Paloma García-Casas ◽  
Chiara Fornetto ◽  
Sonia Sonda ◽  
Paola Pizzo ◽  
...  
Keyword(s):  
Animal Models ◽  
Synaptic Transmission ◽  
Neurodegenerative Diseases ◽  
Neuronal Plasticity ◽  
Brain Function ◽  
Brain Research ◽  
Neuronal Survival ◽  
Neuronal Function ◽  
Brain Physiology

Calcium (Ca2+) signaling coordinates are crucial processes in brain physiology. Particularly, fundamental aspects of neuronal function such as synaptic transmission and neuronal plasticity are regulated by Ca2+, and neuronal survival itself relies on Ca2+-dependent cascades. Indeed, impaired Ca2+ homeostasis has been reported in aging as well as in the onset and progression of neurodegeneration. Understanding the physiology of brain function and the key processes leading to its derangement is a core challenge for neuroscience. In this context, Ca2+ imaging represents a powerful tool, effectively fostered by the continuous amelioration of Ca2+ sensors in parallel with the improvement of imaging instrumentation. In this review, we explore the potentiality of the most used animal models employed for Ca2+ imaging, highlighting their application in brain research to explore the pathogenesis of neurodegenerative diseases.

scholarly journals Sex-steroid-dependent plasticity of brain-stem autonomic circuits

2020 ◽  
Vol 319 (1) ◽  
pp. R60-R68
Author(s):  
Erica L. Littlejohn ◽  
Stephanie Fedorchak ◽  
Carie R. Boychuk
Keyword(s):  
Nervous System ◽  
Brain Stem ◽  
Sex Hormones ◽  
Nucleus Tractus Solitarius ◽  
Critical Role ◽  
Vagal Afferents ◽  
Motor Nucleus ◽  
Peripheral Sensory ◽  
The Brain

In the central nervous system (CNS), nuclei of the brain stem play a critical role in the integration of peripheral sensory information and the regulation of autonomic output in mammalian physiology. The nucleus tractus solitarius of the brain stem acts as a relay center that receives peripheral sensory input from vagal afferents of the nodose ganglia, integrates information from within the brain stem and higher central centers, and then transmits autonomic efferent output through downstream premotor nuclei, such as the nucleus ambiguus, the dorsal motor nucleus of the vagus, and the rostral ventral lateral medulla. Although there is mounting evidence that sex and sex hormones modulate autonomic physiology at the level of the CNS, the mechanisms and neurocircuitry involved in producing these functional consequences are poorly understood. Of particular interest in this review is the role of estrogen, progesterone, and 5α-reductase-dependent neurosteroid metabolites of progesterone (e.g., allopregnanolone) in the modulation of neurotransmission within brain-stem autonomic neurocircuits. This review will discuss our understanding of the actions and mechanisms of estrogen, progesterone, and neurosteroids at the cellular level of brain-stem nuclei. Understanding the complex interaction between sex hormones and neural signaling plasticity of the autonomic nervous system is essential to elucidating the role of sex in overall physiology and disease.

scholarly journals Brief freezing steps lead to robust immunofluorescence in the Drosophila nervous system

BioTechniques ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 299-305
Author(s):  
Ada Thapa ◽  
Shea M Sullivan ◽  
Minh Q Nguyen ◽  
Dominic Buckley ◽  
Vy T Ngo ◽  
...  
Keyword(s):  
Nervous System ◽  
Drosophila Melanogaster ◽  
Neurodegenerative Disease ◽  
Spatial Organization ◽  
Molecular Mechanisms ◽  
Structural Integrity ◽  
Antibody Specificity ◽  
Proteolytic Digestion ◽  
Neuronal Function ◽  
The Brain

Drosophila melanogaster possesses a complex nervous system, regulating sophisticated behavioral outputs, that serves as a powerful model for dissecting molecular mechanisms underlying neuronal function and neurodegenerative disease. Immunofluorescence techniques provide a way to visualize the spatiotemporal organization of these networks, permitting observation of their development, functional location, remodeling and, eventually, degradation. However, basic immunostaining techniques do not always result in efficient antibody penetration through the brain, and supplemental techniques to enhance permeability can compromise structural integrity, altering spatial organization. Here, slow freezing of brains is shown to facilitate antibody permeability without loss of antibody specificity or brain integrity. To demonstrate the advantages of this freezing technique, the results of two commonly used permeation methods – detergent-based and partial proteolytic digestion – are compared.

scholarly journals Wilhelm Siegmund Feldberg, C. B. E. 19 November 1900—23 October 1993

1997 ◽  
Vol 43 ◽  
pp. 145-170 ◽  
Author(s):  
G. W. Bisset ◽  
T. V. P. Bliss
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Transmission ◽  
20Th Century ◽  
Mode Of Action ◽  
Experimental Approach ◽  
Chemical Nature ◽  
Working Life ◽  
The Central Nervous System ◽  
The Brain

Wilhelm Siegmund Feldberg, one of the greatest neuropharmacologists of the 20th century, was born in Hamburg on 19 November 1900. During a working life of 65 years, he published over 350 papers. His early work in Berlin on the pharmacology of histamine and acetylcholine was followed in the 1930s by his fundamental work with Dale, which finally established the chemical nature of synaptic transmission in the peripheral nervous system. In later years he turned to the central nervous system, introducing a new and widely adopted experimental approach to elucidate the site and mode of action of drugs in the brain.

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