scholarly journals Dichotomous Activity and Function of Neurons with Low- and High-Frequency Discharge in the External Globus Pallidus of Non-Human Primates

2021 ◽  
Author(s):  
Shiran Katabi ◽  
Avital Adler ◽  
Marc Deffains ◽  
Hagai Bergman
Keyword(s):  
Globus Pallidus ◽  
High Frequency ◽  
Functional Importance ◽  
High Frequency Discharge ◽  
Neuronal Populations ◽  
Behavioral Cues ◽  
Almost All ◽  
And Function ◽  
Human Primate ◽  
Spiking Activity

To date, there is a consensus that there are at least two neuronal populations in the non-human primate (NHP) external globus pallidus (GPe): the low- and high-frequency discharge (LFD and HFD) neurons. Nevertheless, almost all NHP physiological studies have neglected the functional importance of LFD neurons. This study examined the discharge features of these two GPe neuronal subpopulations recorded in four NHPs engaged in a classical conditioning task with cues predicting reward, neutral and aversive outcomes. The results show that LFD neurons tended to burst, encoded the salience of behavioral cues, and exhibited correlated spiking activity. By contrast, the HFD neurons tended to pause, encoded cue valence, and exhibited uncorrelated spiking activity. Overall, these findings point to the dichotomic organization of the NHP GPe which is likely to be critical to the implementation of normal basal ganglia functions and computations.

scholarly journals Statistical Properties of Pauses of the High-Frequency Discharge Neurons in the External Segment of the Globus Pallidus

2007 ◽  
Vol 27 (10) ◽  
pp. 2525-2538 ◽  
Author(s):  
S. Elias ◽  
M. Joshua ◽  
J. A. Goldberg ◽  
G. Heimer ◽  
D. Arkadir ◽  
...  
Keyword(s):  
Globus Pallidus ◽  
High Frequency ◽  
Statistical Properties ◽  
High Frequency Discharge

Balance of Increases and Decreases in Firing Rate of the Spontaneous Activity of Basal Ganglia High-Frequency Discharge Neurons

2008 ◽  
Vol 100 (6) ◽  
pp. 3086-3104 ◽  
Author(s):  
Shlomo Elias ◽  
Ya'acov Ritov ◽  
Hagai Bergman
Keyword(s):  
Basal Ganglia ◽  
Spontaneous Activity ◽  
High Frequency ◽  
Discharge Rate ◽  
Behavioral Activity ◽  
Spontaneous Discharge ◽  
Inhibitory Input ◽  
Remarkable Change ◽  
High Frequency Discharge ◽  
Almost All

Most neurons in the external and internal segments of the globus pallidus and the substantia nigra pars reticulata (GPe, GPi, and SNr) are characterized by a high-frequency discharge (HFD) rate (50–80 Hz) that, in most GPe neurons, is also interrupted by pauses. Almost all (∼90%) of the synaptic inputs to these HFD neurons are GABAergic and inhibitory. Nevertheless, their responses to behavioral events are usually dominated by increases in discharge rate. Additionally, there are no reports of prolonged bursts in the spontaneous activity of these cells that could reflect their disinhibition by GPe pauses. We recorded the spontaneous activity of 385 GPe, GPi, and SNr HFD neurons during a quiet-wakeful state from two monkeys. We developed three complementary methods to quantify the balance of increases and decreases in the spontaneous discharge of HFD neurons and validated them by simulations. Unlike the behavioral evoked responses, the spontaneous activity of pallidal and SNr neurons is not dominated by increases. Moreover, the activity of basal ganglia neurons does not include bursts that could reflect disinhibition by the spontaneous pauses of GPe neurons. These findings suggest that the discharge increase/decrease balance during a quiet-wakeful state better reflects the inhibitory input of the HFD basal ganglia neurons than during responses to behavioral events; however, the GPe pauses are not echoed by comparable bursts either in the GPe or in the output nuclei. Changes in the excitatory drive of these structures (e.g., during behavioral activity) thus may lead to a remarkable change in this balance.

scholarly journals Roles of HIF and 2-Oxoglutarate-Dependent Dioxygenases in Controlling Gene Expression in Hypoxia

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 350
Author(s):  
Julianty Frost ◽  
Mark Frost ◽  
Michael Batie ◽  
Hao Jiang ◽  
Sonia Rocha
Keyword(s):  
Gene Expression ◽  
Hypoxia Inducible Factor ◽  
Transcriptional Regulator ◽  
Hydroxylase Activity ◽  
Control Of Gene Expression ◽  
Prolyl Hydroxylases ◽  
Chromatin Organisation ◽  
Sense And Respond ◽  
Almost All ◽  
And Function

Hypoxia—reduction in oxygen availability—plays key roles in both physiological and pathological processes. Given the importance of oxygen for cell and organism viability, mechanisms to sense and respond to hypoxia are in place. A variety of enzymes utilise molecular oxygen, but of particular importance to oxygen sensing are the 2-oxoglutarate (2-OG) dependent dioxygenases (2-OGDs). Of these, Prolyl-hydroxylases have long been recognised to control the levels and function of Hypoxia Inducible Factor (HIF), a master transcriptional regulator in hypoxia, via their hydroxylase activity. However, recent studies are revealing that dioxygenases are involved in almost all aspects of gene regulation, including chromatin organisation, transcription and translation. We highlight the relevance of HIF and 2-OGDs in the control of gene expression in response to hypoxia and their relevance to human biology and health.

scholarly journals The Cross-Talk between Mesenchymal Stem Cells and Immune Cells in Tissue Repair and Regeneration

2021 ◽  
Vol 22 (5) ◽  
pp. 2472
Author(s):  
Carl Randall Harrell ◽  
Valentin Djonov ◽  
Vladislav Volarevic
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Immune Cells ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Multipotent Stem Cells ◽  
Tissue Repair And Regeneration ◽  
Almost All ◽  
And Function

Mesenchymal stem cells (MSCs) are self-renewable, rapidly proliferating, multipotent stem cells which reside in almost all post-natal tissues. MSCs possess potent immunoregulatory properties and, in juxtacrine and paracrine manner, modulate phenotype and function of all immune cells that participate in tissue repair and regeneration. Additionally, MSCs produce various pro-angiogenic factors and promote neo-vascularization in healing tissues, contributing to their enhanced repair and regeneration. In this review article, we summarized current knowledge about molecular mechanisms that regulate the crosstalk between MSCs and immune cells in tissue repair and regeneration.

scholarly journals Actively revealing card attack on card-based protocols

2021 ◽  
Author(s):  
Ken Takashima ◽  
Daiki Miyahara ◽  
Takaaki Mizuki ◽  
Hideaki Sone
Keyword(s):  
Secure Computation ◽  
Malicious Attack ◽  
Formal Framework ◽  
Almost All ◽  
And Function

AbstractIn 1989, den Boer presented the first card-based protocol, called the “five-card trick,” that securely computes the AND function using a deck of physical cards via a series of actions such as shuffling and turning over cards. This protocol enables a couple to confirm their mutual love without revealing their individual feelings. During such a secure computation protocol, it is important to keep any information about the inputs secret. Almost all existing card-based protocols are secure under the assumption that all players participating in a protocol are semi-honest or covert, i.e., they do not deviate from the protocol if there is a chance that they will be caught when cheating. In this paper, we consider a more malicious attack in which a player as an active adversary can reveal cards illegally without any hesitation. Against such an actively revealing card attack, we define the t-secureness, meaning that no information about the inputs leaks even if at most t cards are revealed illegally. We then actually design t-secure AND protocols. Thus, our contribution is the construction of the first formal framework to handle actively revealing card attacks as well as their countermeasures.

Kv3.1–Kv3.2 Channels Underlie a High-Voltage–Activating Component of the Delayed Rectifier K+ Current in Projecting Neurons From the Globus Pallidus

1999 ◽  
Vol 82 (3) ◽  
pp. 1512-1528 ◽  
Author(s):  
R. Hernández-Pineda ◽  
A. Chow ◽  
Y. Amarillo ◽  
H. Moreno ◽  
M. Saganich ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Globus Pallidus ◽  
High Frequency ◽  
Calcium Binding ◽  
Repetitive Firing ◽  
Delayed Rectifier ◽  
Expression Systems ◽  
Electrophysiological Properties ◽  
Channel Proteins ◽  
Heterologous Expression Systems

The globus pallidus plays central roles in the basal ganglia circuitry involved in movement control as well as in cognitive and emotional functions. There is therefore great interest in the anatomic and electrophysiological characterization of this nucleus. Most pallidal neurons are GABAergic projecting cells, a large fraction of which express the calcium binding protein parvalbumin (PV). Here we show that PV-containing pallidal neurons coexpress Kv3.1 and Kv3.2 K+ channel proteins and that both Kv3.1 and Kv3.2 antibodies coprecipitate both channel proteins from pallidal membrane extracts solubilized with nondenaturing detergents, suggesting that the two channel subunits are forming heteromeric channels. Kv3.1 and Kv3.2 channels have several unusual electrophysiological properties when expressed in heterologous expression systems and are thought to play special roles in neuronal excitability including facilitating sustained high-frequency firing in fast-spiking neurons such as interneurons in the cortex and the hippocampus. Electrophysiological analysis of freshly dissociated pallidal neurons demonstrates that these cells have a current that is nearly identical to the currents expressed by Kv3.1 and Kv3.2 proteins in heterologous expression systems, including activation at very depolarized membrane potentials (more positive than −10 mV) and very fast deactivation rates. These results suggest that the electrophysiological properties of native channels containing Kv3.1 and Kv3.2 proteins in pallidal neurons are not significantly affected by factors such as associated subunits or postranslational modifications that result in channels having different properties in heterologous expression systems and native neurons. Most neurons in the globus pallidus have been reported to fire sustained trains of action potentials at high-frequency. Kv3.1–Kv3.2 voltage-gated K+channels may play a role in helping maintain sustained high-frequency repetitive firing as they probably do in other neurons.

Mesencephalic GABA neuronal development: no more on the other side of oblivion

2014 ◽  
Vol 5 (5) ◽  
pp. 371-382 ◽  
Author(s):  
Suyan Li ◽  
Sampada Joshee ◽  
Anju Vasudevan
Keyword(s):  
Transcriptional Control ◽  
Neuronal Development ◽  
Developmental Regulation ◽  
Molecular Characteristics ◽  
Psychiatric Illnesses ◽  
Neuronal Populations ◽  
Gaba Neurons ◽  
Recent Developments ◽  
And Function ◽  
The Brain

AbstractMidbrain GABA neurons, endowed with multiple morphological, physiological and molecular characteristics as well as projection patterns are key players interacting with diverse regions of the brain and capable of modulating several aspects of behavior. The diversity of these GABA neuronal populations based on their location and function in the dorsal, medial or ventral midbrain has challenged efforts to rapidly uncover their developmental regulation. Here we review recent developments that are beginning to illuminate transcriptional control of GABA neurons in the embryonic midbrain (mesencephalon) and discuss its implications for understanding and treatment of neurological and psychiatric illnesses.

High-Frequency Discharge as an Ion Source

Nature ◽  
1946 ◽  
Vol 158 (4002) ◽  
pp. 61-61 ◽  
Author(s):  
P. C. THONEMANN
Keyword(s):  
High Frequency ◽  
Ion Source ◽  
High Frequency Discharge

scholarly journals Soil ammonia-oxidizing archaea in a paddy field with different irrigation and fertilization managements

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Limin Wang ◽  
Dongfeng Huang
Keyword(s):  
Ammonia Oxidation ◽  
Chemical Properties ◽  
Paddy Soils ◽  
Soil Nitrification ◽  
Treated Soil ◽  
Ammonia Oxidizing Archaea ◽  
Rice Yields ◽  
Traditional Irrigation ◽  
Almost All ◽  
And Function

AbstractBecause ammonia-oxidizing archaea (AOA) are ubiquitous and highly abundant in almost all terrestrial soils, they play an important role in soil nitrification. However, the changes in the structure and function of AOA communities and their edaphic drivers in paddy soils under different fertilization and irrigation regimes remain unclear. In this study, we investigated AOA abundance, diversity and activity in acid paddy soils by a field experiment. Results indicated that the highest potential ammonia oxidation (PAO) (0.011 μg NO 2 -  –N g-1 d.w.day-1) was found in T2 (optimal irrigation and fertilization)—treated soils, whereas the lowest PAO (0.004 μg NO 2 -  –N g-1 d.w.day-1) in T0 (traditional irrigation)- treated soils. Compared with the T0—treated soil, the T2 treatment significantly (P < 0.05) increased AOA abundances. Furthermore, the abundance of AOA was significantly (P < 0.01) positively correlated with pH, soil organic carbon (SOC), and PAO. Meanwhile, pH and SOC content were significantly (P < 0.05) higher in the T2—treated soil than those in the T1 (traditional irrigation and fertilization)- treated soil. In addition, these two edaphic factors further influenced the AOA community composition. The AOA phylum Crenarchaeota was mainly found in the T2—treated soils. Phylogenetic analysis revealed that most of the identified OTUs of AOA were mainly affiliated with Crenarchaeota. Furthermore, the T2 treatment had higher rice yield than the T0 and T1 treatments. Together, our findings confirm that T2 might ameliorate soil chemical properties, regulate the AOA community structure, increase the AOA abundance, enhance PAO and consequently maintain rice yields in the present study.

scholarly journals STEM-17. NOT ALL GBM STEM CELLS ARE EQUAL: IMPLICATIONS FOR RESEARCH AND THERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii199-ii200
Author(s):  
Luciano Galdieri ◽  
Arijita Jash ◽  
Olga Malkova ◽  
Diane Mao ◽  
Jian Campian ◽  
...  
Keyword(s):  
Stem Cells ◽  
Phenotypic Diversity ◽  
Treatment Resistance ◽  
Surface Markers ◽  
Mass Cytometry ◽  
Pathway Activation ◽  
Almost All ◽  
And Function ◽  
Activation Status

Abstract Glioblastoma (GBM) kills almost all patients within 2 years. A subpopulation of cells, GBM stem cells (GSCs), contributes to treatment resistance and recurrence. A major therapeutic goal is to kill GSCs, but no targeted therapy yet exists. Since their discovery, GSCs have been isolated using single surface markers, such as CD15, CD44, CD133, and a-6 integrin. It remains unknown how these single surface marker-defined GSC populations compare to each other in terms of signal transduction and function and whether expression of different combinations of these markers is associated with distinct phenotypes. Using mass cytometry and fresh operating room specimens, we found that 15 distinct GSC subpopulations exist in vivo and they differ in their MEK/ERK, WNT, and AKT pathway activation status. In culture, some subpopulations were lost and previously undetectable ones materialized. GSCs highly expressing all four surface markers had the greatest self-renewal capacity and in vivo tumorigenicity as well as the strongest WNT pathway activation. This work highlights the signaling and phenotypic diversity in GSC subpopulations, together suggesting that not all GSCs are equivalent. These observations should be considered when studying GSCs in the laboratory, with implications for the development of treatments that target GSCs and prevent tumor recurrence in patients.

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