scholarly journals Breathing-driven prefrontal oscillations regulate maintenance of conditioned-fear evoked freezing independently of initiation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sophie Bagur ◽  
Julie M. Lefort ◽  
Marie M. Lacroix ◽  
Gaëtan de Lavilléon ◽  
Cyril Herry ◽  
...  
Keyword(s):  
Functional Role ◽  
Population Analysis ◽  
Conditioned Fear ◽  
Stable State ◽  
Network Activity ◽  
Power Dynamics ◽  
Potential Mechanism ◽  
Physiological Basis ◽  
Dorsomedial Prefrontal Cortex ◽  
Shed Light

AbstractBrain–body interactions are thought to be essential in emotions but their physiological basis remains poorly understood. In mice, regular 4 Hz breathing appears during freezing after cue-fear conditioning. Here we show that the olfactory bulb (OB) transmits this rhythm to the dorsomedial prefrontal cortex (dmPFC) where it organizes neural activity. Reduction of the respiratory-related 4 Hz oscillation, via bulbectomy or optogenetic perturbation of the OB, reduces freezing. Behavioural modelling shows that this is due to a specific reduction in freezing maintenance without impacting its initiation, thus dissociating these two phenomena. dmPFC LFP and firing patterns support the region’s specific function in freezing maintenance. In particular, population analysis reveals that network activity tracks 4 Hz power dynamics during freezing and reaches a stable state at 4 Hz peak that lasts until freezing termination. These results provide a potential mechanism and a functional role for bodily feedback in emotions and therefore shed light on the historical James–Cannon debate.

scholarly journals Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4139
Author(s):  
Barbora Vénosová ◽  
Ingrid Jelemenská ◽  
Jozef Kožíšek ◽  
Peter Rapta ◽  
Michal Zalibera ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Oxidation State ◽  
Central Atom ◽  
Population Analysis ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Theoretical Methods ◽  
Ni Oxidation ◽  
Shed Light

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

scholarly journals Hypocretin (orexin) is critical in sustaining theta/gamma-rich waking behaviors that drive sleep need

2017 ◽  
Vol 114 (27) ◽  
pp. E5464-E5473 ◽  
Author(s):  
Anne Vassalli ◽  
Paul Franken
Keyword(s):  
Slow Wave Sleep ◽  
Paradoxical Sleep ◽  
Brain Activity ◽  
Network Activity ◽  
Power Dynamics ◽  
Poor Sleep ◽  
Sleep Homeostasis ◽  
Episode Duration ◽  
Global Brain ◽  
Motivated Behaviors

Hcrt gene inactivation in mice leads to behavioral state instability, abnormal transitions to paradoxical sleep, and cataplexy, hallmarks of narcolepsy. Sleep homeostasis is, however, considered unimpaired in patients and narcoleptic mice. We find that whereas Hcrtko/ko mice respond to 6-h sleep deprivation (SD) with a slow-wave sleep (SWS) EEG δ (1.0 to 4.0 Hz) power rebound like WT littermates, spontaneous waking fails to induce a δ power reflecting prior waking duration. This correlates with impaired θ (6.0 to 9.5 Hz) and fast-γ (55 to 80 Hz) activity in prior waking. We algorithmically identify a theta-dominated wakefulness (TDW) substate underlying motivated behaviors and typically preceding cataplexy in Hcrtko/ko mice. Hcrtko/ko mice fully implement TDW when waking is enforced, but spontaneous TDW episode duration is greatly reduced. A reformulation of the classic sleep homeostasis model, where homeostatic pressure rises exclusively in TDW rather than all waking, predicts δ power dynamics both in Hcrtko/ko and WT mouse baseline and recovery SWS. The low homeostatic impact of Hcrtko/ko mouse spontaneous waking correlates with decreased cortical expression of neuronal activity-related genes (notably Bdnf, Egr1/Zif268, and Per2). Thus, spontaneous TDW stability relies on Hcrt to sustain θ/fast-γ network activity and associated plasticity, whereas other arousal circuits sustain TDW during SD. We propose that TDW identifies a discrete global brain activity mode that is regulated by context-dependent neuromodulators and acts as a major driver of sleep homeostasis. Hcrt loss in Hcrtko/ko mice causes impaired TDW maintenance in baseline wake and blunted δ power in SWS, reproducing, respectively, narcolepsy excessive daytime sleepiness and poor sleep quality.

scholarly journals Environmental Assessment of Relationships and Mutual Influences in the System “Protective Forest Plantations – Anthropogenic Landscapes”

2021 ◽  
Vol 940 (1) ◽  
pp. 012083
Author(s):  
S Abu Deeb ◽  
T Tkachenko ◽  
V Mileikovskyi
Keyword(s):  
Adverse Effects ◽  
Natural Resource Management ◽  
Functional Role ◽  
Quantitative Assessment ◽  
Stable State ◽  
Ecological Monitoring ◽  
Forest Plantations ◽  
Equilibrium Stability ◽  
Anthropogenic Landscapes ◽  
Protective Forest

Abstract Protective forest plantations (PFP) play an essential functional role in the operation of anthropogenic landscapes (AL). A study of processes in the system “PFP-AL” was conducted in the Boguslav agroforestry state, Kyiv region, Ukraine, to maintain sustainability. A method of ecological monitoring has been proposed to achieve environmental equilibrium stability. The calculations show the stable state of the ecosystem. A graphic-analytical method for quantitative assessment of the potential adverse effects of natural resource management has been proposed. It is shown that additional compensation of adverse effects is necessary, which can be performed by green structures.

scholarly journals Regional order in the South Pacific and Fiji’s challenge to it

2021 ◽  
Author(s):  
◽  
John Gradwell
Keyword(s):  
South Pacific ◽  
International Order ◽  
Power Dynamics ◽  
The South ◽  
Global Trends ◽  
The Past ◽  
Recent Developments ◽  
Regional Order ◽  
Legitimate State ◽  
Shed Light

<p>Drawing from a body of leading literature on international and regional order, this thesis applies these concepts to the context of the South Pacific. Examining recent developments in the region through a framework of international order, and paying specific consideration to the regional operation of legitimacy, institutions and power dynamics, it seeks to shed light on the forces underpinning Fiji’s pursuit of regionalism through alternative institutional frameworks. In this, it concludes that Suva’s actions over the past decades constitute a challenge to the prevailing, Australian-New Zealand led regional order in the South Pacific, one that has occurred largely from a failure of Wellington and Canberra’s policymakers to appreciate first, changing power dynamics brought about by the entry of the “new players” into the region and second, divergent views throughout the region on what constitutes legitimate state conduct. Drawing these conclusions into the broader context of global international order, this thesis unpacks the distinct meanings and motivations underpinning these developments, and in doing so explores how regional developments have mirrored global trends in the American led liberal order, offering lessons for policymakers both within the region and beyond.</p>

scholarly journals Short but Continuous Natural Pain during Meditation Sittings for Depression Treatment: A Case Report

2018 ◽  
Author(s):  
Mingwei Huang
Keyword(s):  
Case Report ◽  
Common Mental Disorder ◽  
Depression Treatment ◽  
Potential Mechanism ◽  
Major Depressive ◽  
Specific Component ◽  
Physiological Basis ◽  
The Individual ◽  
Underlying Pathology ◽  
Universal Treatment

Major depressive disorder (MDD) is a common mental disorder, which results in seriously impaired condition in the patients and great global disability burden. In light of its quite diverse etiologies, comorbidity with many other diseases, and complex underlying pathology, it has been a great challenge to understand the physiological basis of MDD, which may be a complex of related diseases, rather than a single one. In addition to the partial understanding of MDD, the individual heterogeneities among patients may render the development of a universal treatment an elusive goal. But studying how each of currently available treatments affects the disease can generate useful information to stratify patients into different subtypes for individualized treatments. In this case report, we present the first report of repeated success of using meditation as the only treatment of MDD, compared to initial success but no remission with other conventional antidepressants on the same patient. We hypothesized that the short but continuous natural pain during one-hour meditation sittings has the therapeutic effect to treat depression in the case of this patient and potentially others with MDD. This special opportunity of eliminating tremendous heterogeneity among different individuals has enabled us to probe deeply into the potential mechanism of depression treatments and the complex physiology of depression itself, both of which have likely profound implications in the treatment of other MDD patients as well. More importantly, this case report helps us to dissect one specific component of meditation for its long-known and well-established benefit against depression.

scholarly journals Cooperative cation co-transport by supramolecular self-associating amphiphiles

2021 ◽  
Author(s):  
Kylie Yang ◽  
Jessica Boles ◽  
Lisa White ◽  
Kira Hilton ◽  
Hin Yuk Lai ◽  
...  
Keyword(s):  
Cation Transport ◽  
Potential Mechanism ◽  
Microbial Toxicity ◽  
Transport Assay ◽  
Shed Light

We report investigations into the cation transport ability of a series of antimicrobial supramolecular, self-associating amphiphiles (SSAs). The SSAs proved to be challenging to study using standard, literature assays and we therefore describe a novel methodology to examine cation transport via a chloride co-transport assay. One SSA in this series was observed to function as a K+ and Na+ transporter with promising deliverability properties. The results shed light on a potential mechanism of microbial toxicity and inform the design of future targets.

Disrupting Mughal Imperialism: Piracy and Plunder on the Indian Ocean

2020 ◽  
Vol 8 (1) ◽  
pp. 128-142
Author(s):  
Srinivas Reddy
Keyword(s):  
Seventeenth Century ◽  
Indian Ocean ◽  
South Asia ◽  
Western Indian Ocean ◽  
Power Dynamics ◽  
Broad View ◽  
The Indian Ocean ◽  
Shed Light

Abstract This paper examines five distinct events from seventeenth-century South Asia: a pirate raid, two battles and two more pirate raids, all of which represent varying acts of defiance committed against the great Mughal imperium. Perpetrated by the Portuguese, the Marathas and the British, on land and by sea, these events seen in sequence shed light on the evolution of geopolitical players and the aqueous shifts in power dynamics related to maritime supremacy in the western Indian Ocean. By taking a broad view of this area over the span of a century, this paper seeks to explore the how notions of piracy, privateering, imperialism and colonialism evolved and changed in correspondence with a diverse, vital and hotly contested seascape.

Bukhara Center

2020 ◽  
pp. 73-97
Author(s):  
James Pickett
Keyword(s):  
Human Impact ◽  
Social Power ◽  
Social World ◽  
Power Dynamics ◽  
High Culture ◽  
Terra Incognita ◽  
The Social ◽  
The World ◽  
Social Currency ◽  
Shed Light

This chapter assesses the human impact of Bukhara's efflorescence. To what extent did Bukhara's cosmological centrality manifest in actual networks of human exchange? How far did Bukhara's allure extend, and from what points of origin were people willing to travel there for education in its colossal madrasa establishment? The story of centering the cosmopolis for a regional constituency and of deploying the corresponding social currency within that context is one that could equally be told about any number of other Persianate nodes: Lahore, Isfahan, Istanbul, and beyond. Bukhara was not unique in this regard. However, this pivot between cosmopolitan high culture and social power dynamics at the subregional level remains terra incognita. Texts were resonant across vast swathes of territory, but the mechanics of the world undergirding them are left to the imagination in much of the extant scholarship. Yet these ideas were not merely floating in the ether, and the paths taken by the ulama of Bukhara can perhaps shed light on the social world producing, and produced by, cosmopolitan transculturation. Ultimately, the chapter traces the geographical trajectories of the Islamic scholars at the heart of this study, revealing a regional cultural–religious network that revolved around Bukhara the Noble, the Abode of Knowledge.

Pathogenic Effects of Anti-Glycoprotein Ib Antibodies on Megakaryocytes and Platelets

2002 ◽  
Vol 88 (12) ◽  
pp. 1039-1046 ◽  
Author(s):  
Gulie Alimardani ◽  
Josette Guichard ◽  
Serge Fichelson ◽  
Elisabeth Cramer
Keyword(s):  
Electron Microscopy ◽  
Platelet Adhesion ◽  
Potential Mechanism ◽  
Antithrombotic Drugs ◽  
Pathological Effect ◽  
Thrombocytopenic Purpura ◽  
Platelet Recovery ◽  
Platelet Release ◽  
Shed Light ◽  
Pathogenic Effects

SummaryAntibodies directed against the glycoprotein (GP) Ib have been identified as the potential cause of various platelet disorders: Immune thrombocytopenic purpura (ITP) may be caused by such autoantibodies; Anti-thrombotic drugs targeting GPIb also induce thrombocytopenia. In order to elucidate the potential mechanism(s) of the anti-GPIb effects, we have examined by electron microscopy (EM) the effect of several antibodies directed against GPIb and GPIIb-IIIa on human culture megakaryocytes (MK). Virtually all antibodies to GPIb enhanced the interaction of newly formed platelets with MK when compared to other antibodies. These effects were retrieved when antibodies were tested on platelets. We conclude that antibodies to GPIb can potentially inhibit platelet release by MK, and can also induce homotypic platelet adhesion. These results may have implications in the pathophysiology of thrombocytopenia and platelet recovery in ITP, and shed light on the pathological effect of anti-GPIb antibodies used as antithrombotic drugs.

Contrast-coding in amblyopia. I. Differences in the neural basis of human amblyopia

1983 ◽  
Vol 217 (1208) ◽  
pp. 309-330 ◽  
Keyword(s):  
Visual Development ◽  
Neural Basis ◽  
Physiological Basis ◽  
Low Contrast ◽  
Spatial Frequencies ◽  
Matching Procedure ◽  
Contrast Perception ◽  
Contrast Matching ◽  
Contrast Range ◽  
Shed Light

To shed light on the basis of normal contrast perception in general and its susceptibility during early visual development in particular the contrast-coding deficit of amblyopic eyes was investigated. This was accomplished by using two different but complementary paradigms, one involving equating the contrast sensations between the amblyopic and normal fellow eye and the other involving the assessment of incremental sensitivity at different contrast levels. Since human amblyopia is known to have three different forms, representatives of each were tested. These include strabismics, anisometropes and astigmats. The results of the contrast-matching approach suggest that (i) strabismic and anisometropic (including meridional) amblyopes show important differences in supra-threshold contrast matching (this difference, which occurs across different spatial frequencies, at different luminances and for different field sizes, suggests a different neural basis for the two main forms of human amblyopia); (ii) all forms of amblyopia share one common feature, that of large threshold losses relative to the extent of the suprathreshold anomaly; (iii) the accelerating growth in subjective contrast above the raised threshold shown by the matching procedure is not evident in the assessment of incremental contrast sensitivity. From these results it is argued that, although contrast perception (in the low contrast range) is disturbed in amblyopia, amblyopia cannot be adequately understood in these terms alone. This raises important questions for our understanding of the physiological basis of contrast-coding in normal vision and its perceptual importance.

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