scholarly journals A specific role for serotonin in overcoming effort cost

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Florent Meyniel ◽  
Guy M Goodwin ◽  
JF William Deakin ◽  
Corinna Klinge ◽  
Christine MacFadyen ◽  
...  
Keyword(s):  
Physiological Role ◽  
Force Production ◽  
Multiple Roles ◽  
Monetary Incentives ◽  
Behavioral Regulation ◽  
Clinical Trial Registration ◽  
Healthy Humans ◽  
Computational Effect ◽  
The Impact

Serotonin is implicated in many aspects of behavioral regulation. Theoretical attempts to unify the multiple roles assigned to serotonin proposed that it regulates the impact of costs, such as delay or punishment, on action selection. Here, we show that serotonin also regulates other types of action costs such as effort. We compared behavioral performance in 58 healthy humans treated during 8 weeks with either placebo or the selective serotonin reuptake inhibitor escitalopram. The task involved trading handgrip force production against monetary benefits. Participants in the escitalopram group produced more effort and thereby achieved a higher payoff. Crucially, our computational analysis showed that this effect was underpinned by a specific reduction of effort cost, and not by any change in the weight of monetary incentives. This specific computational effect sheds new light on the physiological role of serotonin in behavioral regulation and on the clinical effect of drugs for depression.Clinical trial Registration: ISRCTN75872983

scholarly journals Interphotoreceptor coupling: an evolutionary perspective

2021 ◽  
Author(s):  
Lorenzo Cangiano ◽  
Sabrina Asteriti
Keyword(s):  
Visual Information ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physiological Role ◽  
Cellular Processes ◽  
Contact Points ◽  
Highly Sensitive ◽  
The Many ◽  
The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

scholarly journals Immunotoxicity of Xenobiotics in Fish: A Role for the Aryl Hydrocarbon Receptor (AhR)?

2021 ◽  
Vol 22 (17) ◽  
pp. 9460
Author(s):  
Helmut Segner ◽  
Christyn Bailey ◽  
Carolina Tafalla ◽  
Jun Bo
Keyword(s):  
Immune System ◽  
Aryl Hydrocarbon Receptor ◽  
Disease Susceptibility ◽  
Immune Cell ◽  
Physiological Role ◽  
Immune Gene ◽  
Immune Systems ◽  
Aryl Hydrocarbon ◽  
The Impact

The impact of anthropogenic contaminants on the immune system of fishes is an issue of growing concern. An important xenobiotic receptor that mediates effects of chemicals, such as halogenated aromatic hydrocarbons (HAHs) and polyaromatic hydrocarbons (PAHs), is the aryl hydrocarbon receptor (AhR). Fish toxicological research has focused on the role of this receptor in xenobiotic biotransformation as well as in causing developmental, cardiac, and reproductive toxicity. However, biomedical research has unraveled an important physiological role of the AhR in the immune system, what suggests that this receptor could be involved in immunotoxic effects of environmental contaminants. The aims of the present review are to critically discuss the available knowledge on (i) the expression and possible function of the AhR in the immune systems of teleost fishes; and (ii) the impact of AhR-activating xenobiotics on the immune systems of fish at the levels of immune gene expression, immune cell proliferation and immune cell function, immune pathology, and resistance to infectious disease. The existing information indicates that the AhR is expressed in the fish immune system, but currently, we have little understanding of its physiological role. Exposure to AhR-activating contaminants results in the modulation of numerous immune structural and functional parameters of fish. Despite the diversity of fish species studied and the experimental conditions investigated, the published findings rather uniformly point to immunosuppressive actions of xenobiotic AhR ligands in fish. These effects are often associated with increased disease susceptibility. The fact that fish populations from HAH- and PAH-contaminated environments suffer immune disturbances and elevated disease susceptibility highlights that the immunotoxic effects of AhR-activating xenobiotics bear environmental relevance.

scholarly journals Molecular Hydrogen, a Neglected Key Driver of Soil Biogeochemical Processes

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Sarah Piché-Choquette ◽  
Philippe Constant
Keyword(s):  
Energy Requirement ◽  
Keystone Species ◽  
Physiological Role ◽  
Atp Synthesis ◽  
Potential Contribution ◽  
Biogeochemical Processes ◽  
Individual Level ◽  
C Cycling ◽  
The Impact

ABSTRACTThe atmosphere of the early Earth is hypothesized to have been rich in reducing gases such as hydrogen (H2). H2has been proposed as the first electron donor leading to ATP synthesis due to its ubiquity throughout the biosphere as well as its ability to easily diffuse through microbial cells and its low activation energy requirement. Even today, hydrogenase enzymes enabling the production and oxidation of H2are found in thousands of genomes spanning the three domains of life across aquatic, terrestrial, and even host-associated ecosystems. Even though H2has already been proposed as a universal growth and maintenance energy source, its potential contribution as a driver of biogeochemical cycles has received little attention. Here, we bridge this knowledge gap by providing an overview of the classification, distribution, and physiological role of hydrogenases. Distribution of these enzymes in various microbial functional groups and recent experimental evidence are finally integrated to support the hypothesis that H2-oxidizing microbes are keystone species driving C cycling along O2concentration gradients found in H2-rich soil ecosystems. In conclusion, we suggest focusing on the metabolic flexibility of H2-oxidizing microbes by combining community-level and individual-level approaches aiming to decipher the impact of H2on C cycling and the C-cycling potential of H2-oxidizing microbes, via both culture-dependent and culture-independent methods, to give us more insight into the role of H2as a driver of biogeochemical processes.

Pathophysiology of β2-glycoprotein I in antiphospholipid syndrome

Lupus ◽  
2010 ◽  
Vol 19 (4) ◽  
pp. 379-384 ◽  
Author(s):  
E. Matsuura ◽  
L. Shen ◽  
Y. Matsunami ◽  
N. Quan ◽  
M. Makarova ◽  
...  
Keyword(s):  
Vascular Disease ◽  
Antiphospholipid Syndrome ◽  
Mechanism Of Action ◽  
Antiphospholipid Antibodies ◽  
Physiological Role ◽  
Therapeutic Strategies ◽  
Physiological Functions ◽  
Glycoprotein I ◽  
The Impact

Since β2-glycoprotein I (β2GPI) was described as the major antigenic target for antiphospholipid antibodies, many studies have focused their attention to the physiological role of β2GPI and anti-β2GPI antibodies on autoimmune-mediated thrombosis. Studies reporting the physiological role of β2GPI have been numerous, but the exact mechanism of action(s) has yet to be completely determined. β2GPI’s epitopes for anti-β2GPI autoantibodies have been characterized, however, not all of the heterogeneous anti-β2GPI antibodies are pathogenic. The pathophysiologic role of β2GPI has been reported in the fields of coagulation, fibrinolysis, angiogenesis, and atherosclerosis. Our understanding of the impact of β2GPI, its metabolites and autoantibodies to β2GPI on these physiological functions may contribute to the development of better therapeutic strategies to treat and prevent autoimmune-mediated atherothrombotic vascular disease. Lupus (2010) 19, 379—384.

scholarly journals Targeted disruption of G protein-coupled bile acid receptor 1 (Gpbar1/M-Bar) in mice

2006 ◽  
Vol 191 (1) ◽  
pp. 197-205 ◽  
Author(s):  
Takaharu Maruyama ◽  
Kenichi Tanaka ◽  
Jun Suzuki ◽  
Hiroyuki Miyoshi ◽  
Naomoto Harada ◽  
...  
Keyword(s):  
Bile Acid ◽  
G Protein ◽  
Physiological Role ◽  
Wild Type ◽  
Fat Accumulation ◽  
Acid Receptor ◽  
Bile Acid Receptor ◽  
The Impact ◽  
G Protein Coupled

G protein-coupled bile acid receptor 1 (Gpbar1/M-Bar) is a novel G protein-coupled receptor for bile acid. Tissue distribution and cell-type specificity of Gpbar1 mRNA suggest a potential role for the receptor in the endocrine system; however, the precise physiological role of Gpbar1 still remains to be elucidated. To investigate the role of Gpbar1 in vivo, the Gpbar1 gene was disrupted in mice. In homozygous mice, total bile acid pool size was significantly decreased by 21–25% compared with that of the wild-type mice, suggesting that Gpbar1 contributes to bile acid homeostasis. In order to assess the impact of Gpbar1 deficiency in bile acid homeostasis more precisely, Gpbar1 homozygous mice were fed a high-fat diet for 2 months. As a result, female Gpbar1 homozygous mice showed significant fat accumulation with body weight gain compared with that of the wild-type mice. These findings were also observed in heterozygous mice to the same extent. Although the precise mechanism for fat accumulation in female Gpbar1 homozygous mice remains to be addressed, these data indicate that Gpbar1 is a potential new player in energy homeostasis. Thus, Gpbar1-deficient mice are useful in elucidating new physiological roles for Gpbar1.

scholarly journals Evidence for a physiological role of pulmonary arterial baroreceptors in sympathetic neural activation in healthy humans

2020 ◽  
Vol 598 (5) ◽  
pp. 955-965 ◽  
Author(s):  
Lydia L. Simpson ◽  
Victoria L. Meah ◽  
Andrew Steele ◽  
Suman Thapamagar ◽  
Christopher Gasho ◽  
...  
Keyword(s):  
Physiological Role ◽  
Neural Activation ◽  
Arterial Baroreceptors ◽  
Healthy Humans ◽  
Pulmonary Arterial

The Endothelin System in Cardiovascular Physiology and Pathophysiology

1997 ◽  
Vol 2 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Richard J Parris ◽  
David J Webb
Keyword(s):  
Physiological Role ◽  
Regulatory Peptides ◽  
Endothelin Receptor ◽  
Endothelin 1 ◽  
Healthy Humans ◽  
Endothelin Antagonists ◽  
Endothelin System ◽  
Potent Vasoconstrictor ◽  
Atherosclerotic Process

Endothelin-1, a member of a novel family of regulatory peptides, is the most potent vasoconstrictor and pressor substance known. Endothelin-1 is a 21-amino-acid endothelium-derived peptide causing uniquely sustained vasoconstriction. In addition, endothelin-1 has pronounced effects on the coronary, renal and cerebral circulations, enhances responses to other vasoconstrictors, and is comitogenic. Recent studies have shown that the endothelins are essential for normal fetal development, and that endothelin-1 plays an important physiological role in the regulation of basal vascular tone and blood pressure in healthy humans. There is now also a wealth of evidence suggesting that endothelin-1 is a key mediator in a range of cardiovascular diseases associated with sustained vasoconstriction, such as chronic heart failure, and with vasospasm, such as subarachnoid haemorrhage. In addition, endothelin-1 appears to act in opposition to nitric oxide to promote the atherosclerotic process. There are a large number of oral and intravenously active endothelin antagonists entering clinical development and a number of clinical studies, particularly with endothelin receptor antagonists, are now under way. Such studies are beginning to define the role of the endothelins in cardiovascular disease and to confirm the potential of the endothelin system as an important new therapeutic target.

scholarly journals Interleukin-6 deficiency modulates testicular function by increasing the expression of suppressor of cytokine signaling 3 (SOCS3) in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thaís Alves-Silva ◽  
Geanne Arantes Freitas ◽  
Talita Guerreiro Rodrigues Húngaro ◽  
Adriano Cleis Arruda ◽  
Lila Missae Oyama ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Reproductive Tract ◽  
Physiological Role ◽  
Cytokine Signaling ◽  
Sperm Production ◽  
Suppressor Of Cytokine Signaling ◽  
Male Reproductive Tract ◽  
The Impact ◽  
Daily Sperm Production

AbstractSeveral cytokines have been reported to participate in spermatogenesis, including interleukin-6 (IL6). However, not many studies have been conducted on the loss of Il6 on the male reproductive tract. Nonetheless, there is considerable knowledge regarding the pathological and physiological role of IL6 on spermatogenesis. In this way, this study evaluated the impact of Il6 deficiency on mice testicles in the absence of infection or inflammation. We showed that Il6 deficiency increases daily sperm production, the number of spermatids, and the testicular testosterone and dihydrotestosterone levels. Besides that, mice with a deleted Il6 (IL6KO) showed increased testicular SOCS3 levels, with no changes in pJAK/JAK and pSTAT3/STAT3 ratios. It is worth noting that the aforementioned pathway is not the only pathway to up-regulate SOCS3, nor is it the only SOCS3 target, thus proposing that the increase of SOCS3 in the testis occurs independently of the JAK-STAT signaling in IL6KO mice. Therefore, we suggest that the lack of Il6 drives androgenic production by increasing SOCS3 in the testis, thus leading to an increase in spermatogenesis.

scholarly journals Deficiency in MT5-MMP Supports Branching of Human iPSCs-Derived Neurons and Reduces Expression of GLAST/S100 in iPSCs-Derived Astrocytes

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1705
Author(s):  
Nikita Arnst ◽  
Pedro Belio-Mairal ◽  
Laura García-González ◽  
Laurie Arnaud ◽  
Louise Greetham ◽  
...  
Keyword(s):  
Physiological Role ◽  
Neuronal Morphology ◽  
App Processing ◽  
Amyloidogenic Processing ◽  
Model Of Alzheimer’S Disease ◽  
Human Neurons ◽  
Human Ipscs ◽  
Induced Pluripotent ◽  
The Impact

For some time, it has been accepted that the β-site APP cleaving enzyme 1 (BACE1) and the γ-secretase are two main players in the amyloidogenic processing of the β-amyloid precursor protein (APP). Recently, the membrane-type 5 matrix metalloproteinase (MT5-MMP/MMP-24), mainly expressed in the nervous system, has been highlighted as a new key player in APP-processing, able to stimulate amyloidogenesis and also to generate a neurotoxic APP derivative. In addition, the loss of MT5-MMP has been demonstrated to abrogate pathological hallmarks in a mouse model of Alzheimer’s disease (AD), thus shedding light on MT5-MMP as an attractive new therapeutic target. However, a more comprehensive analysis of the role of MT5-MMP is necessary to evaluate how its targeting affects neurons and glia in pathological and physiological situations. In this study, leveraging on CRISPR-Cas9 genome editing strategy, we established cultures of human-induced pluripotent stem cells (hiPSC)-derived neurons and astrocytes to investigate the impact of MT5-MMP deficiency on their phenotypes. We found that MT5-MMP-deficient neurons exhibited an increased number of primary and secondary neurites, as compared to isogenic hiPSC-derived neurons. Moreover, MT5-MMP-deficient astrocytes displayed higher surface area and volume compared to control astrocytes. The MT5-MMP-deficient astrocytes also exhibited decreased GLAST and S100β expression. These findings provide novel insights into the physiological role of MT5-MMP in human neurons and astrocytes, suggesting that therapeutic strategies targeting MT5-MMP should be controlled for potential side effects on astrocytic physiology and neuronal morphology.

scholarly journals Force Generation Profiles of Para-Nordic Sit-Skiers Representing Different Physical Impairments

2021 ◽  
Author(s):  
Magdalena Karczewska-Lindinger ◽  
Vesa Linnamo ◽  
Valeria Rosso ◽  
Laura Gastaldi ◽  
Walter Rapp ◽  
...  
Keyword(s):  
Force Production ◽  
Force Generation ◽  
Maximum Speed ◽  
Propulsive Force ◽  
Trunk Flexion ◽  
World Cup ◽  
Double Poling ◽  
Cycle Lengths ◽  
The Impact

Abstract Purpose To biomechanically profile force generation connected to the complex role of the trunk in double poling in a representative sample of Para-Nordic sit-skiers. Methods Twelve male World Cup Para-Nordic sit-skiers (sport classes: LW10–12) were skiing on flat snow terrain at submaximal speed of 4.5 m/s (~ 73% maximum speed). 2D video (50 Hz) and pole force analyses (1000 Hz) were performed synchronously, examining angle, force and cycle characteristics to analyse the role of the trunk in generating propulsion. Results LW10–11.5 skiers lost between 21% and 4% propulsive force versus LW12 athletes only due to different geometrics of the trunk and pole angle at an equal axial pole force. While LW10–11 skiers indicated trunk extension or position maintenance during pole thrust, LW11.5–12 skiers showed strong trunk flexion combined with smaller pole angles to the ground. Hence, LW11.5–12 skiers could create larger propulsive forces and therefore greater cycle lengths at lower cycle rates at the same speed. Maximum speed increased from LW10 to LW12 and was significantly correlated to trunk flexion range of motion (r = 0.63) and cycle length (r = 0.59). Trunk flexion ROM showed a significant relationship to the impulse of propulsive force (r = 0.63) and pole angle to the ground (r = − 0.76) (all P < 0.05). Conclusion The impact of impairment on the force production profiles and its physiological-biomechanical consequences need further investigation also in other terrains and at wider spectrums of skiing speeds. The evident problem of low numbers of LW10–11 skiers in World Cup needs creative future solutions for research.

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