Astrocytes, as well as neurons, express a diversity of ion channels

1992 ◽  
Vol 70 (S1) ◽  
pp. S223-S238 ◽  
Author(s):  
H. Sontheimer
Keyword(s):  
Ion Channels ◽  
Ion Channel ◽  
Brain Regions ◽  
Regional Heterogeneity ◽  
The Past ◽  
Channel Expression ◽  
Cell Processes ◽  
Ion Channel Development ◽  
The Brain

The electrophysiologist's view of brain astrocytes has changed markedly in recent years. In the past astrocytes were viewed as passive, K+ selective cells, but it is now evident that they are capable of expressing voltage- and ligand-activated channels previously thought to be restricted to neurons. The functional importance of most of these ion channels is not understood at present. However, from studies of astrocytes cultured from different species and brain regions, we learned that like their neuronal counterparts astrocytes are a heterogeneous group of brain cells showing similar heterogeneity in their ion-channel expression. Not only are subpopulations of astrocytes within areas of the brain equipped with specific sets of ion channels but, furthermore, regional heterogeneity is apparent. In addition, astrocyte ion channel expression is dynamic and changes during development. Some ion channels are only expressed postnatally, yet others appear to be expressed only during certain stages of development. Interestingly, the expression of some astrocyte channels, including Na+, Ca2+, and some K+ channels, appears to be controlled by neurons via mechanisms that are presently unknown. Some studies suggest roles for astrocyte channels in basic cell processes such as cell proliferation. Thus, although the role of some astrocyte channels remains unclear, our understanding of astrocyte physiology is starting to take shape and points towards roles of ion channels not involved in electrogenesis.Key words: astrocyte, ion channel, development, review, transmitter receptor.

Neuro-Clinical Signatures of Language Impairments: A Theoretical Framework for Function-to-structure Mapping in Clinics

2020 ◽  
Vol 20 (9) ◽  
pp. 800-811 ◽  
Author(s):  
Ferath Kherif ◽  
Sandrine Muller
Keyword(s):  
Brain Mapping ◽  
Theoretical Framework ◽  
Brain Regions ◽  
Language Impairments ◽  
Structure Mapping ◽  
Language Functions ◽  
The Past ◽  
Language Recovery ◽  
The Brain ◽  
Bow Tie

In the past decades, neuroscientists and clinicians have collected a considerable amount of data and drastically increased our knowledge about the mapping of language in the brain. The emerging picture from the accumulated knowledge is that there are complex and combinatorial relationships between language functions and anatomical brain regions. Understanding the underlying principles of this complex mapping is of paramount importance for the identification of the brain signature of language and Neuro-Clinical signatures that explain language impairments and predict language recovery after stroke. We review recent attempts to addresses this question of language-brain mapping. We introduce the different concepts of mapping (from diffeomorphic one-to-one mapping to many-to-many mapping). We build those different forms of mapping to derive a theoretical framework where the current principles of brain architectures including redundancy, degeneracy, pluri-potentiality and bow-tie network are described.

Chemo- and Optogenetic Strategies for the Elucidation of Pain Pathways

2019 ◽  
pp. 816-832 ◽  
Author(s):  
Sascha R. A. Alles ◽  
Anne-Marie Malfait ◽  
Richard J. Miller
Keyword(s):  
Chronic Pain ◽  
Pain Response ◽  
Conscious Perception ◽  
Novel Therapies ◽  
The Past ◽  
Nociceptive Pathways ◽  
Pain Pathways ◽  
Technical Advances ◽  
The Brain

Pain is not a simple phenomenon and, beyond its conscious perception, involves circuitry that allows the brain to provide an affective context for nociception, which can influence mood and memory. In the past decade, neurobiological techniques have been developed that allow investigators to elucidate the importance of particular groups of neurons in different aspects of the pain response, something that may have important translational implications for the development of novel therapies. Chemo- and optogenetics represent two of the most important technical advances of recent times for gaining understanding of physiological circuitry underlying complex behaviors. The use of these techniques for teasing out the role of neurons and glia in nociceptive pathways is a rapidly growing area of research. The major findings of studies focused on understanding circuitry involved in different aspects of nociception and pain are highlighted in this article. In addition, attention is drawn to the possibility of modification of chemo- and optogenetic techniques for use as potential therapies for treatment of chronic pain disorders in human patients.

scholarly journals The Microbiota–Gut–Brain Axis and Alzheimer Disease. From Dysbiosis to Neurodegeneration: Focus on the Central Nervous System Glial Cells

2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi
Keyword(s):  
Alzheimer Disease ◽  
Glial Cells ◽  
Cell Types ◽  
The Past ◽  
The Central Nervous System ◽  
Diseased State ◽  
The Brain ◽  
Alzheimer Disease Pathogenesis ◽  
Brain Homeostasis

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.

scholarly journals Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit

2021 ◽  
Vol 15 ◽  
Author(s):  
Louis-Philippe Bernier ◽  
Clément Brunner ◽  
Azzurra Cottarelli ◽  
Matilde Balbi
Keyword(s):  
Brain Function ◽  
Energy Demand ◽  
Neurovascular Unit ◽  
Cell Types ◽  
Brain Regions ◽  
Regional Heterogeneity ◽  
Regional Specialization ◽  
Multiple Cell ◽  
Cellular Components ◽  
The Brain

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.

scholarly journals Physiology and Therapeutic Potential of SK, H, and M Medium AfterHyperPolarization Ion Channels

2021 ◽  
Vol 14 ◽  
Author(s):  
Deepanjali Dwivedi ◽  
Upinder S. Bhalla
Keyword(s):  
Ion Channels ◽  
Therapeutic Potential ◽  
Neurological Diseases ◽  
Brain Regions ◽  
Channel Activity ◽  
Current Review ◽  
Cellular Excitability ◽  
M Channels ◽  
Neuronal Functions

SK, HCN, and M channels are medium afterhyperpolarization (mAHP)-mediating ion channels. The three channels co-express in various brain regions, and their collective action strongly influences cellular excitability. However, significant diversity exists in the expression of channel isoforms in distinct brain regions and various subcellular compartments, which contributes to an equally diverse set of specific neuronal functions. The current review emphasizes the collective behavior of the three classes of mAHP channels and discusses how these channels function together although they play specialized roles. We discuss the biophysical properties of these channels, signaling pathways that influence the activity of the three mAHP channels, various chemical modulators that alter channel activity and their therapeutic potential in treating various neurological anomalies. Additionally, we discuss the role of mAHP channels in the pathophysiology of various neurological diseases and how their modulation can alleviate some of the symptoms.

Tumor Classification Based on Regional Heterogeneity Using Pixel Level Feature Descriptors

2021 ◽  
Vol 11 (5) ◽  
pp. 1481-1488
Author(s):  
C. Gunasundari ◽  
K. Selva Bhuvaneswari
Keyword(s):  
Texture Analysis ◽  
Early Stage ◽  
Pituitary Tumors ◽  
Brain Regions ◽  
Regional Heterogeneity ◽  
Gradient Based ◽  
Classification Of Tumors ◽  
Effective Diagnosis ◽  
The Brain

Brain tumor is considered to be widely analyzed disease for effective diagnosis and treatment planning. Several approaches were framed to detect and diagnose tumor at early stage. In this work, texture analysis is carried out to analyze the nature of tumor and categorize it. Around 3064 images were analyzed during this study consisting of meningioma, glioma and pituitary tumors. Intensity and gradient pixel based texture analysis is carried out in this analysis. Results confirm that the tumors can be classified and categorized based on the intensity and gradient pixel information. A total of 2216 feature vector is extracted it is observed that the gradient based information aids for better classification of tumors. Localized binary patterns are found to provide detailed information about the subtle variation in the brain regions due to the presence of abnormality in brain tissues. It is further observed that the normalized feature vectors show better differentiation between tumor categories. The ROC and PRC curves exhibit the high classification ability using the extracted features to differentiate tumor grades.

Role of adrenal catecholamines in cerebrovasodilation evoked from brain stem

1987 ◽  
Vol 252 (6) ◽  
pp. H1183-H1191
Author(s):  
C. Iadecola ◽  
P. M. Lacombe ◽  
M. D. Underwood ◽  
T. Ishitsuka ◽  
D. J. Reis
Keyword(s):  
Brain Function ◽  
Blood Gases ◽  
Brain Regions ◽  
Elevated Plasma ◽  
Regional Cerebral Blood ◽  
Medullary Reticular Formation ◽  
Alpha Chloralose ◽  
The Brain ◽  
Stimulation Of

We studied whether adrenal medullary catecholamines (CAs) contribute to the metabolically linked increase in regional cerebral blood flow (rCBF) elicited by electrical stimulation of the dorsal medullary reticular formation (DMRF). Rats were anesthetized (alpha-chloralose, 30 mg/kg), paralyzed, and artificially ventilated. The DMRF was electrically stimulated with intermittent trains of pulses through microelectrodes stereotaxically implanted. Blood gases were controlled and, during stimulation, arterial pressure was maintained within the autoregulated range for rCBF. rCBF and blood-brain barrier (BBB) permeability were determined in homogenates of brain regions by using [14C]iodoantipyrine and alpha-aminoisobutyric acid (AIB), respectively, as tracers. Plasma CAs (epinephrine and norepinephrine) were measured radioenzymatically. DMRF stimulation increased rCBF throughout the brain (n = 5; P less than 0.01, analysis of variance) and elevated plasma CAs substantially (n = 4). Acute bilateral adrenalectomy abolished the increase in plasma epinephrine (n = 4), reduced the increases in flow (n = 6) in cerebral cortex (P less than 0.05), and abolished them elsewhere in brain (P greater than 0.05). Comparable effects on rCBF were obtained by selective adrenal demedullation (n = 7) or pretreatment with propranolol (1.5 mg/kg iv) (n = 5). DMRF stimulation did not increase the permeability of the BBB to AIB (n = 5). We conclude that the increases in rCBF elicited from the DMRF has two components, one dependent on, and the other independent of CAs. Since the BBB is impermeable to CAs and DMRF stimulation fails to open the BBB, the results suggest that DMRF stimulation allows, through a mechanism not yet determined, circulating CAs to act on brain and affect brain function.

scholarly journals Neural Substrates of Social Status Inference: Roles of Medial Prefrontal Cortex and Superior Temporal Sulcus

2014 ◽  
Vol 26 (5) ◽  
pp. 1131-1140 ◽  
Author(s):  
Malia Mason ◽  
Joe C. Magee ◽  
Susan T. Fiske
Keyword(s):  
Social Order ◽  
Neural Substrates ◽  
Brain Regions ◽  
Third Party ◽  
Social Interdependence ◽  
Medial Pfc ◽  
State Inference ◽  
The Brain ◽  
Track Status

The negotiation of social order is intimately connected to the capacity to infer and track status relationships. Despite the foundational role of status in social cognition, we know little about how the brain constructs status from social interactions that display it. Although emerging cognitive neuroscience reveals that status judgments depend on the intraparietal sulcus, a brain region that supports the comparison of targets along a quantitative continuum, we present evidence that status judgments do not necessarily reduce to ranking targets along a quantitative continuum. The process of judging status also fits a social interdependence analysis. Consistent with third-party perceivers judging status by inferring whose goals are dictating the terms of the interaction and who is subordinating their desires to whom, status judgments were associated with increased recruitment of medial pFC and STS, brain regions implicated in mental state inference.

scholarly journals The NCX3 Isoform of the Na+/Ca2+ Exchanger Contributes to Neuroprotection Elicited by Ischemic Postconditioning

2010 ◽  
Vol 31 (1) ◽  
pp. 362-370 ◽  
Author(s):  
Giuseppe Pignataro ◽  
Elga Esposito ◽  
Ornella Cuomo ◽  
Rossana Sirabella ◽  
Francesca Boscia ◽  
...  
Keyword(s):  
Brain Regions ◽  
Ischemic Postconditioning ◽  
Intracerebroventricular Infusion ◽  
Ionic Transporters ◽  
Relevant Role ◽  
Ischemic Episode ◽  
Study Support ◽  
Interfering Rna ◽  
The Brain

It has been recently shown that a short sublethal brain ischemia subsequent to a prolonged harmful ischemic episode may confer ischemic neuroprotection, a phenomenon termed ischemic postconditioning. Na+/Ca2+ exchanger (NCX) isoforms, NCX1, NCX2, and NCX3, are plasma membrane ionic transporters widely distributed in the brain and involved in the control of Na+ and Ca2+ homeostasis and in the progression of stroke damage. The objective of this study was to evaluate the role of these three proteins in the postconditioning-induced neuroprotection. The NCX protein and mRNA expression was evaluated at different time points in the ischemic temporoparietal cortex of rats subjected to tMCAO alone or to tMCAO plus ischemic postconditioning. The results of this study showed that NCX3 protein and ncx3 mRNA were upregulated in those brain regions protected by postconditioning treatment. These changes in NCX3 expression were mediated by the phosphorylated form of the ubiquitously expressed serine/threonine protein kinase p-AKT, as the p-AKT inhibition prevented NCX3 upregulation. The relevant role of NCX3 during postconditioning was further confirmed by results showing that NCX3 silencing, induced by intracerebroventricular infusion of small interfering RNA (siRNA), partially reverted the postconditioning-induced neuroprotection. The results of this study support the idea that the enhancement of NCX3 expression and activity might represent a reasonable strategy to reduce the infarct extension after stroke.

scholarly journals Neural Underpinnings of Obesity: The Role of Oxidative Stress and Inflammation in the Brain

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1018
Author(s):  
Caitlyn A. Mullins ◽  
Ritchel B. Gannaban ◽  
Md Shahjalal Khan ◽  
Harsh Shah ◽  
Md Abu B. Siddik ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Energy Homeostasis ◽  
Dorsal Striatum ◽  
Brain Regions ◽  
Therapeutic Interventions ◽  
Low Grade ◽  
Obesity Prevalence ◽  
Beneficial Effects ◽  
The Brain

Obesity prevalence is increasing at an unprecedented rate throughout the world, and is a strong risk factor for metabolic, cardiovascular, and neurological/neurodegenerative disorders. While low-grade systemic inflammation triggered primarily by adipose tissue dysfunction is closely linked to obesity, inflammation is also observed in the brain or the central nervous system (CNS). Considering that the hypothalamus, a classical homeostatic center, and other higher cortical areas (e.g. prefrontal cortex, dorsal striatum, hippocampus, etc.) also actively participate in regulating energy homeostasis by engaging in inhibitory control, reward calculation, and memory retrieval, understanding the role of CNS oxidative stress and inflammation in obesity and their underlying mechanisms would greatly help develop novel therapeutic interventions to correct obesity and related comorbidities. Here we review accumulating evidence for the association between ER stress and mitochondrial dysfunction, the main culprits responsible for oxidative stress and inflammation in various brain regions, and energy imbalance that leads to the development of obesity. Potential beneficial effects of natural antioxidant and anti-inflammatory compounds on CNS health and obesity are also discussed.

Sign in / Sign up

Export Citation Format

Share Document