scholarly journals A continuum hypothesis of psychotomimetic rapid antidepressants

2021 ◽  
Vol 5 ◽  
pp. 239821282110077
Author(s):  
Joost Haarsma ◽  
Catherine J Harmer ◽  
Sandra Tamm

Ketamine, classical psychedelics and sleep deprivation are associated with rapid effects on depression. Interestingly, these interventions also have common psychotomimetic actions, mirroring aspects of psychosis such as an altered sense of self, perceptual distortions and distorted thinking. This raises the question whether these interventions might be acute antidepressants through the same mechanisms that underlie some of their psychotomimetic effects. That is, perhaps some symptoms of depression can be understood as occupying the opposite end of a spectrum where elements of psychosis can be found on the other side. This review aims at reviewing the evidence underlying a proposed continuum hypothesis of psychotomimetic rapid antidepressants, suggesting that a range of psychotomimetic interventions are also acute antidepressants as well as trying to explain these common features in a hierarchical predictive coding framework, where we hypothesise that these interventions share a common mechanism by increasing the flexibility of prior expectations. Neurobiological mechanisms at play and the role of different neuromodulatory systems affected by these interventions and their role in controlling the precision of prior expectations and new sensory evidence will be reviewed. The proposed hypothesis will also be discussed in relation to other existing theories of antidepressants. We also suggest a number of novel experiments to test the hypothesis and highlight research areas that could provide further insights, in the hope to better understand the acute antidepressant properties of these interventions.

2019 ◽  
Author(s):  
Lilla Hodossy ◽  
Manos Tsakiris

The experience of one’s embodied sense of self is dependent on the integration of signals originating both from within and outwith one’s body. During the processing and integration of these signals, the bodily self must maintain a fine balance between stability and malleability. Here we investigate the potential role of autonomic responses in interoceptive processing and their contribution to the stability of the bodily self. Using a biofeedback paradigm, we manipulated the congruency of cardiac signals across two hierarchical levels: (i) the low-level congruency between a visual feedback and participant’s own cardiac signal and (ii) the high-level congruency between the participants’ beliefs about the identity of the cardiac feedback and its true identity. We measured the effects of these manipulations on high-frequency heart rate variability (HF-HRV), a selective index of phasic vagal cardiac control. In Experiment 1, HF-HRV was sensitive to low-level congruency, independently of whether participants attempted to regulate or simply attend to the biofeedback. Experiment 2 revealed a higher-level congruency effect, as participants’ prior veridical beliefs increased HF-HRV while when false they decreased HF-HRV. Our results demonstrate that autonomic changes in HF-HRV are sensitive to congruencies across multiple hierarchical levels. Our findings have important theoretical implications for predictive coding models of the self as they pave the way for a more direct way to track the subtle changes in the co-processing of the internal and external milieus.


2020 ◽  
Vol 27 (4) ◽  
pp. 188-205
Author(s):  
Beate M. Herbert

Abstract. The importance of the sense of ourselves from within for understanding adaptive behavior and psychopathology has been increasingly recognized during the last decades. Interoception builds the foundation of our embodied self and dysfunctional interoception lies at the core of many psychosomatic disorders. Eating is fundamental for survival with consequences for health and well-being. It is deeply grounded in homoeostatic and allostatic psychophysiological needs and is driven by interoceptive signals of the body. This narrative review summarizes a selection of empirical findings and draws conclusions on the role of interoception in eating behavior, body weight, and eating disorders. Beyond disordered eating behavior, eating disorders are characterized by impairment of the sense of self, with dysfunctional interoception at its core. Predictive coding accounts are addressed to integrate conclusions and to underline the relevance of interventions to modify interoception.


2020 ◽  
Vol 13 ◽  
Author(s):  
Kumari Jyoti ◽  
Punyasloka Pattnaik ◽  
Tej Singh

Background:: Synthesis of metallic nanoparticles has attracted extensive vitality in numerous research areas such as drug delivery, biomedicine, catalysis etc. where continuous efforts are being made by scientists and engineers to investigate new dimensions for both technological and industrial advancements. Amongst numerous metallic nanoparticles, silver nanoparticle (AgNPs) is a novel metal species with low toxicity, higher stability and significant chemical, physical and biological properties. Methods:: In this, various methods for the fabrication of AgNPs are summarized. Importantly, we concentrated on the role of reducing agents of different plants parts, various working conditions such as AgNO3 concentration; ratio of AgNO3/extract; incubation time; centrifugal conditions, size and shapes. Results:: This study suggested that eco-friendly and non toxic biomolecules present in the extracts (e.g. leaf, stem and root) of plants are used as reducing and capping agents for silver nanoparticles fabrication. This method of fabrication of silver nanoparticles using plants extracts is comparatively cost-effective and simple. A silver salt is simply reduced by biomolecules present in the extracts of these plants. In this review, we have emphasized the synthesis and antibacterial potential of silver nanoparticles using various plant extracts. Conclusion:: Fabrication of silver nanoparticles using plant extracts have advantage over the other physical methods, as it is safe, eco-friendly and simple to use. Plants have huge potential for the fabrication of silver nanoparticles of wide potential of applications with desired shape and size.


Religions ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 284
Author(s):  
Wojciech Rodzeń ◽  
Małgorzata Maria Kulik ◽  
Agnieszka Malinowska ◽  
Zdzisław Kroplewski ◽  
Małgorzata Szcześniak

Does the way we think or feel about ourselves have an impact on our anger-based reactions? Is the direction and strength of this relationship direct, or affected by other factors as well? Given that there is a lack of research on the loss of self-dignity and anger, the first aim of the present study consisted in examining whether or not there is a connection between both variables, with particular emphasis on early adulthood. The second purpose was to explore the moderating role of religiosity on the relationship between loss of self-dignity and anger. Methods: Data were gathered from 462 participants aged 18 to 35. The main methods applied were the Questionnaire of Sense of Self-Dignity, Buss–Perry Aggression Questionnaire, and Religious Meaning System Questionnaire. The results show a statistically significant positive correlation between loss of self-dignity and anger, a negative correlation between religiosity and anger, and no significant association between the loss of self-dignity and religiosity. However, all other dimensions of the sense of self-dignity correlated positively with religiosity. Our findings also confirm that the level of anger resulting from the loss of self-dignity is significantly lower as the level of religiosity increases. Such outcomes seem to support the conception that religiosity may act as a protective factor between the risk (loss of self-dignity) and the outcome factor (anger).


Author(s):  
Hendrik Linz ◽  
Henrik Beuther ◽  
Maryvonne Gerin ◽  
Javier R. Goicoechea ◽  
Frank Helmich ◽  
...  

AbstractThe far-infrared (FIR) regime is one of the wavelength ranges where no astronomical data with sub-arcsecond spatial resolution exist. None of the medium-term satellite projects like SPICA, Millimetron, or the Origins Space Telescope will resolve this malady. For many research areas, however, information at high spatial and spectral resolution in the FIR, taken from atomic fine-structure lines, from highly excited carbon monoxide (CO), light hydrides, and especially from water lines would open the door for transformative science. A main theme will be to trace the role of water in proto-planetary discs, to observationally advance our understanding of the planet formation process and, intimately related to that, the pathways to habitable planets and the emergence of life. Furthermore, key observations will zoom into the physics and chemistry of the star-formation process in our own Galaxy, as well as in external galaxies. The FIR provides unique tools to investigate in particular the energetics of heating, cooling, and shocks. The velocity-resolved data in these tracers will reveal the detailed dynamics engrained in these processes in a spatially resolved fashion, and will deliver the perfect synergy with ground-based molecular line data for the colder dense gas.


2021 ◽  
pp. 003329412110006
Author(s):  
Stephanie Fagan ◽  
Suzanne Hodge ◽  
Charlotte Morris

The study explored experiences of compassion in adults with a diagnosis of Borderline Personality Disorder (BPD) to further the development of the construct of compassion in relation to BPD. Interpretative Phenomenological Analysis was used to develop themes from the narratives of six adults with a diagnosis of BPD. Five themes emerged: Emotional Connection to Suffering, Empathic Understanding, Prioritisation of Needs, A Model of Genuine Compassion and Developing Acceptance and Worth. Participants described the role of compassion in their difficulties, including the adverse impact of experiences of incompassion upon their sense of self. The themes were integrated into a model that highlighted a process of recovery through therapeutic encounters with others in which genuine compassion was modelled. In addition, barriers to compassion and factors facilitating the development of compassion emerged from the analysis and have implications for clinical practice.


2017 ◽  
Vol 474 (16) ◽  
pp. 2713-2731 ◽  
Author(s):  
Athinoula L. Petrou ◽  
Athina Terzidaki

From kinetic data (k, T) we calculated the thermodynamic parameters for various processes (nucleation, elongation, fibrillization, etc.) of proteinaceous diseases that are related to the β-amyloid protein (Alzheimer's), to tau protein (Alzheimer's, Pick's), to α-synuclein (Parkinson's), prion, amylin (type II diabetes), and to α-crystallin (cataract). Our calculations led to ΔG≠ values that vary in the range 92.8–127 kJ mol−1 at 310 K. A value of ∼10–30 kJ mol−1 is the activation energy for the diffusion of reactants, depending on the reaction and the medium. The energy needed for the excitation of O2 from the ground to the first excited state (1Δg, singlet oxygen) is equal to 92 kJ mol−1. So, the ΔG≠ is equal to the energy needed for the excitation of ground state oxygen to the singlet oxygen (1Δg first excited) state. The similarity of the ΔG≠ values is an indication that a common mechanism in the above disorders may be taking place. We attribute this common mechanism to the (same) role of the oxidative stress and specifically of singlet oxygen, (1Δg), to the above-mentioned processes: excitation of ground state oxygen to the singlet oxygen, 1Δg, state (92 kJ mol−1), and reaction of the empty π* orbital with high electron density regions of biomolecules (∼10–30 kJ mol−1 for their diffusion). The ΔG≠ for cases of heat-induced cell killing (cancer) lie also in the above range at 310 K. The present paper is a review and meta-analysis of literature data referring to neurodegenerative and other disorders.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Torbjørn Bjorvatn

PurposeThe purpose of this conceptual paper is to describe and explain how organisations use internal projects to implement organisation-level strategy objectives.Design/methodology/approachTheory development with an emphasis on explaining key constructs and their mutual relationships. The theoretical contribution is represented in a diagram along with a detailed verbal account.FindingsThe paper develops a dynamic, cross-level framework to illustrate the organisational processes and outcomes that determine project-based strategy implementation within a single organisation. The interplay between the base organisation and the project, and benefits realisation were singled out as key future research areas. The proposed framework engages with central discourses in the fields of project management, strategic management, innovation studies, knowledge management and organisation studies.Research limitations/implicationsOnly the contours of an organisation-level theory of strategically motivated internal projects are outlined. Future research must elaborate on the complexities, the non-linear relationships and the boundary conditions that follow from the proposed framework.Practical implicationsManagers are alerted to the strategic role of internal projects, how these projects help connect strategy and performance and what the accompanying organisational processes and outcomes look like.Originality/valueThe paper constitutes an early conceptual treatment of strategy-driven internal projects as a distinct project category, thus addressing a major knowledge gap in project studies. Organisational project-management theory is extended with suggestions for future research.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2072 ◽  
Author(s):  
Heather T Whittaker ◽  
Yichen Qui ◽  
Conceição Bettencourt ◽  
Henry Houlden

Multiple system atrophy (MSA) is one of the few neurodegenerative disorders where we have a significant understanding of the clinical and pathological manifestations but where the aetiology remains almost completely unknown. Research to overcome this hurdle is gaining momentum through international research collaboration and a series of genetic and molecular discoveries in the last few years, which have advanced our knowledge of this rare synucleinopathy. In MSA, the discovery of α-synuclein pathology and glial cytoplasmic inclusions remain the most significant findings. Families with certain types of α-synuclein mutations develop diseases that mimic MSA, and the spectrum of clinical and pathological features in these families suggests a spectrum of severity, from late-onset Parkinson’s disease to MSA. Nonetheless, controversies persist, such as the role of common α-synuclein variants in MSA and whether this disorder shares a common mechanism of spreading pathology with other protein misfolding neurodegenerative diseases. Here, we review these issues, specifically focusing on α-synuclein mutations.


2015 ◽  
Vol 12 (14) ◽  
pp. 4261-4273 ◽  
Author(s):  
D. Hofmann ◽  
G. Preuss ◽  
C. Mätzler

Abstract. An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice-carrying wood. One species, Exidiopsis effusa (Ee), was present on all investigated samples. Both hair-ice-producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity, and that ice segregation is the common mechanism of ice growth on the wood surface. The fungus plays the role of shaping the ice hairs and preventing them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S) compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as being the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.


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