scholarly journals Brain Responses to Ambient Temperature Fluctuations in Fish: Reduction of Blood Volume and Initiation of a Whole-Body Stress Response

2005 ◽  
Vol 93 (5) ◽  
pp. 2849-2855 ◽  
Author(s):  
Erwin H. van den Burg ◽  
Ronald R. Peeters ◽  
Marleen Verhoye ◽  
Johannes Meek ◽  
Gert Flik ◽  
...  
Keyword(s):  
Stress Response ◽  
Ambient Temperature ◽  
Stress Responses ◽  
Anterior Part ◽  
Temperature Drop ◽  
Whole Body ◽  
Pars Intermedia ◽  
Compensatory Mechanism ◽  
Brain Responses ◽  
The Brain

Spatial and temporal ambient temperature variations directly influence cellular biochemistry and thus the physiology of ectotherms. However, many aquatic ectothermic species maintain coordinated sensorimotor function during large acute body-temperature changes, which points to a compensatory mechanism within the neural system. Here we used high-resolution functional magnetic resonance imaging to study brain responses to a drop of 10°C of ambient water temperature in common carp. We observed a strong drainage of blood out of the brain as of 90 s after the onset of the temperature drop, which would be expected to reduce entry of cold blood arriving from the gills so that the change in brain temperature would be slower. Although oxygen content in the brain thus decreased, we still found specific activation in the preoptic area (involved in temperature detection and stress responses), the pituitary pars distalis (stress response), and inactivation of the anterior part of the midbrain tegmentum and the pituitary pars intermedia. We propose that the blood drainage from the brain slows down the cooling of the brain during an acute temperature drop. This could help to maintain proper brain functioning including sensorimotor activity, initiation of the stress response, and the subsequent behavioral responses.

Acute cold stress in rheumatoid arthritis inadequately activates stress responses and induces an increase of interleukin 6

2008 ◽  
Vol 68 (4) ◽  
pp. 572-578 ◽  
Author(s):  
R H Straub ◽  
G Pongratz ◽  
H Hirvonen ◽  
T Pohjolainen ◽  
M Mikkelsson ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Stress Response ◽  
Cold Stress ◽  
Stress Responses ◽  
Plasma Levels ◽  
Acute Stress ◽  
Whole Body ◽  
Cold Therapy ◽  
Before And After ◽  
Sympathetic Stress

Objective:Acute stress in patients with rheumatoid arthritis (RA) should stimulate a strong stress response. After cryotherapy, we expected to observe an increase of hormones of the adrenal gland and the sympathetic nervous system.Methods:A total of 55 patients with RA were recruited for whole-body cryotherapy at −110°C and −60°C, and local cold therapy between −20°C and −30°C for 7 days. We measured plasma levels of steroid hormones, neuropeptide Y (sympathetic marker), and interleukin (IL)6 daily before and after cryotherapy.Results:In both therapy groups with/without glucocorticoids (GC), hormone and IL6 levels at baseline and 5 h after cold stress did not change over 7 days of cryotherapy. In patients without GC, plasma levels of cortisol and androstenedione were highest after −110°C cold stress followed by −60°C or local cold stress. The opposite was found in patients under GC therapy, in whom, unexpectedly, −110°C cold stress elicited the smallest responses. In patients without GC, adrenal cortisol production increased relative to other adrenal steroids, and again the opposite was seen under GC therapy with a loss of cortisol and an increase of dehydroepiandrosterone. Importantly, there was no sympathetic stress response in both groups. Patients without GC and −110°C cold stress demonstrated higher plasma IL6 compared to the other treatment groups (not observed under GC), but they showed the best clinical response.Conclusions:We detected an inadequate stress response in patients with GC. It is further shown that the sympathetic stress response was inadequate in patients with/without GC. Paradoxically, plasma levels of IL6 increased under strong cold stress in patients without GC. These findings confirm dysfunctional stress axes in RA.

Mineralocorticoid Receptors and Glucocorticoid Receptors in HPA Stress Responses During Coping and Adaptation

2020 ◽  
Author(s):  
Edo Ronald de Kloet ◽  
Marian Joëls
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Coping Style ◽  
Glucocorticoid Receptors ◽  
Memory Storage ◽  
Salt Appetite ◽  
Mineralocorticoid Receptors ◽  
Stress Response System ◽  
Appraisal Processes ◽  
The Brain

The glucocorticoid hormones cortisol and corticosterone coordinate circadian events and are master regulators of the stress response. These actions of the glucocorticoids are mediated by mineralocorticoid receptors (NR3C2, or MRs) and glucocorticoid receptors (NR3C1, or GRs). MRs bind the natural glucocorticoids cortisol and corticosterone with a 10-fold higher affinity than GRs. The glucocorticoids are inactivated only in the nucleus tractus solitarii (NTS), rendering the NTS-localized MRs aldosterone-selective and involved in regulation of salt appetite. Everywhere else in the brain MRs are glucocorticoid-preferring. MR and GR are transcription factors involved in gene regulation but recently were also found to mediate rapid non-genomic actions. Genomic MRs, with a predominant localization in limbic circuits, are important for the threshold and sensitivity of the stress response system. Non-genomic MRs promote appraisal processes, memory retrieval, and selection of coping style. Activation of GRs makes energy substrates available and dampens initial defense reactions. In the brain, GR activation enhances appetitive- and fear-motivated behavior and promotes memory storage of the selected coping style in preparation of the future. Thus, MRs and GRs complement each other in glucocorticoid control of the initiation and termination of the stress response, suggesting that the balance in MR- and GR-mediated actions is crucial for homeostasis and health.

scholarly journals Applications of the SR4G Transgenic Zebrafish Line for Biomonitoring of Stress-Disrupting Compounds: A Proof-of-Concept Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Amin Nozari ◽  
Selena Do ◽  
Vance L. Trudeau
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Predictive Models ◽  
Environmental Pollutants ◽  
Whole Body ◽  
Transgenic Zebrafish ◽  
Fluorescence Signal ◽  
Stressed Condition ◽  
Mrna Levels ◽  
Response Class

Transgenic zebrafish models have been successfully used in biomonitoring and risk assessment studies of environmental pollutants, including xenoestrogens, pesticides, and heavy metals. We employed zebrafish larva (transgenic SR4G line) with a cortisol-inducible green fluorescence protein reporter (eGFP) as a model to detect stress responses upon exposure to compounds with environmental impact, including bisphenol A (BPA), vinclozolin (VIN), and fluoxetine (FLX). Cortisol, fluorescence signal, and mRNA levels of eGFP and 11 targeted genes were measured in a homogenized pool of zebrafish larvae, with six experimental replicates for each endpoint. Eleven targeted genes were selected according to their association with stress-axis and immediate early response class of genes. Hydrocortisone (CORT)and dexamethasone (DEX) were used as positive and negative controls, respectively. All measurements were done in two unstressed and stressed condition using standardized net handling as the stressor. A significant positive linear correlation between cortisol levels and eGFP mRNA levels was observed (r> 0.9). Based on eGFP mRNA levels in unstressed and stressed larvae two predictive models were trained (Random Forest and Logistic Regression). Both these models could correctly predict the blunted stress response upon exposure to BPA, VIN, FLX and the negative control, DEX. The negative predictive value (NPV) of these models were 100%. Similar NPV was observed when the predictive models trained based on the mRNA levels of the eleven assessed genes. Measurement of whole-body fluorescence intensity signal was not significant to detect blunted stress response. Our findings support the use of SR4G transgenic larvae as an in vivo biomonitoring model to screen chemicals for their stress-disrupting potentials. This is important because there is increasing evidence that brief exposures to environmental pollutants modify the stress response and critical coping behaviors for several generations.

scholarly journals Evidence of the Cellular Senescence Stress Response in Mitotically Active Brain Cells—Implications for Cancer and Neurodegeneration

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Gregory J. Gillispie ◽  
Eric Sah ◽  
Sudarshan Krishnamurthy ◽  
Mohamed Y. Ahmidouch ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Stress Response ◽  
Neurodegenerative Diseases ◽  
Cell Fate ◽  
Cellular Senescence ◽  
Stress Responses ◽  
Cellular Stress ◽  
Surrounding Tissue ◽  
Brain Cells ◽  
Cell Fate Decisions ◽  
The Brain

Cellular stress responses influence cell fate decisions. Apoptosis and proliferation represent opposing reactions to cellular stress or damage and may influence distinct health outcomes. Clinical and epidemiological studies consistently report inverse comorbidities between age-associated neurodegenerative diseases and cancer. This review discusses how one particular stress response, cellular senescence, may contribute to this inverse correlation. In mitotically competent cells, senescence is favorable over uncontrolled proliferation, i.e., cancer. However, senescent cells notoriously secrete deleterious molecules that drive disease, dysfunction and degeneration in surrounding tissue. In recent years, senescent cells have emerged as unexpected mediators of neurodegenerative diseases. The present review uses pre-defined criteria to evaluate evidence of cellular senescence in mitotically competent brain cells, highlights the discovery of novel molecular regulators and discusses how this single cell fate decision impacts cancer and degeneration in the brain. We also underscore methodological considerations required to appropriately evaluate the cellular senescence stress response in the brain.

scholarly journals Signaling Overlap between the Golgi Stress Response and Cysteine Metabolism in Huntington’s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1468
Author(s):  
Bindu D. Paul
Keyword(s):  
Stress Response ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Corpus Striatum ◽  
Cellular Processes ◽  
Er Stress Response ◽  
Cysteine Metabolism ◽  
The Brain

Huntington’s disease (HD) is caused by expansion of polyglutamine repeats in the protein huntingtin, which affects the corpus striatum of the brain. The polyglutamine repeats in mutant huntingtin cause its aggregation and elicit toxicity by affecting several cellular processes, which include dysregulated organellar stress responses. The Golgi apparatus not only plays key roles in the transport, processing, and targeting of proteins, but also functions as a sensor of stress, signaling through the Golgi stress response. Unlike the endoplasmic reticulum (ER) stress response, the Golgi stress response is relatively unexplored. This review focuses on the molecular mechanisms underlying the Golgi stress response and its intersection with cysteine metabolism in HD.

scholarly journals Effect of beta 1,3 glucan in stress responses of the pencilfish (Nannostomus trifasciatus) during transport within the rio Negro basin

2014 ◽  
Vol 12 (3) ◽  
pp. 623-628 ◽  
Author(s):  
Janessa S. Abreu ◽  
Richard P. Brinn ◽  
Levy C. Gomes ◽  
Dawn Michelle McComb ◽  
Bernardo Baldisserotto ◽  
...  
Keyword(s):  
Survival Rate ◽  
Stress Response ◽  
Stress Responses ◽  
Whole Body ◽  
Positive Effects ◽  
Rio Negro ◽  
Transport Experiment ◽  
In The Beginning ◽  
Rio Negro Basin

We investigated the use of beta 1,3 glucan as an imunostimulant during a transport experiment to determine the effects upon the stress response of the pencilfish (Nannostomus trifasciatus). Pencilfish were fed for seven days with different concentrations of beta 1,3 glucan: 0.0% (control); 0.01%; 0.1% and 0.5% of beta 1,3 glucan per kg of feed-1. Fish were then transported for 24 hours by boat from Barcelos to Manaus. The highest dose of beta 1,3 glucan in the food increased Na+influx after 12 hours of transport and 0.1 and 0.5% beta 1,3 glucan maintained the flux of both ions close to zero at 24 hours. All doses of beta 1,3 glucan reduced K+ loss significantly in the beginning of the transport, but after 12 to 24 hours did not. No significant differences in whole body cortisol or survival were observed. Our results indicate that pencilfish had ionic alterations during transport from Barcelos to Manaus. The lack of significant differences in whole body cortisol and survival rate in addition to the maintenance of Na+ and K+ balance during transport reinforce the positive effects of beta 1,3 glucan immunostimulant on fish homeostasis. Therefore, we recommend its addition to food prior to transport.

scholarly journals Exposure to boat noise in the field yields minimal stress response in wild reef fish

2020 ◽  
Vol 29 ◽  
pp. 93-103 ◽  
Author(s):  
E Staaterman ◽  
AJ Gallagher ◽  
PE Holder ◽  
CH Reid ◽  
AH Altieri ◽  
...  
Keyword(s):  
Stress Response ◽  
Reef Fish ◽  
Stress Responses ◽  
Physiological Stress ◽  
Low Frequency ◽  
Whole Body ◽  
Anthropogenic Noise ◽  
Noisy Environment ◽  
Physiological Stress Response ◽  
Minimal Stress

Aquatic anthropogenic noise is on the rise, with growing concern about its impact on species that are sensitive to low-frequency sounds (e.g. most fish and invertebrates). We investigated whether the reef fish Halichoeres bivittatus living in both noisy and quiet areas had differing levels of baseline stress (measured as whole-body cortisol) and whether they would exhibit a physiological stress response when exposed to boat noise playbacks. While the playback experiments significantly increased cortisol levels in fish from our experiment compared to baseline levels, there were minimal pairwise differences across treatments and no difference in baseline stress for fish living in noisy vs. quiet areas. These results may be explained by low overall auditory sensitivity, habituation to a fairly noisy environment (due to biological sounds), or that boat noise simply may not represent an immediate threat to survival in this species. These findings contrast recent studies that have shown elevated stress responses in fishes when exposed to boat noise and highlights that inter-specific differences must be considered when evaluating potential impacts of anthropogenic noise on marine life.

scholarly journals Structural characterisation of a cyprinid (Cyprinus carpio L.) CRH, CRH-BP and CRH-R1, and the role of these proteins in the acute stress response

2004 ◽  
Vol 32 (3) ◽  
pp. 627-648 ◽  
Author(s):  
MO Huising ◽  
C van Schooten ◽  
AJ Taverne-Thiele ◽  
T Hermsen ◽  
BM Verburg-van Kemenade ◽  
...  
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Acute Stress ◽  
Phylogenetic Analyses ◽  
Pars Intermedia ◽  
Structural Characterisation ◽  
Real Time Quantitative Pcr ◽  
Close Proximity ◽  
Large Fibre ◽  
Acute Stress Response

We elucidated the structure of the principle factors regulating the initiation of the acute stress response in common carp: corticotrophin-releasing hormone (CRH), CRH-receptor 1 (CRH-R1) and CRH-binding protein (CRH-BP). Phylogenetic analyses reveal that these proteins are evolutionarily well conserved in vertebrates. CRH and CRH-BP expression are not co-localised in the same hypothalamic perikarya. On the contrary, CRH-BP expression is limited to the perimeter of the nucleus preopticus (NPO), but is abundant in other regions, including an area directly rostral from, and in close proximity to, the NPO. Despite the lack of co-expression, the nerve fibres projecting onto both the rostral pars distalis (rPD) as well as the large fibre bundles projecting onto the pars intermedia (PI) contain CRH as well as CRH-BP, suggesting that both ACTH release from the rPD as well as the release of PI melanotrope content is regulated via CRH and CRH-BP. Finally, we show via real-time quantitative PCR that expression of hypothalamic CRH and CRH-BP following a 24 h restraint significantly increases, whereas PD CRH-R1 expression decreases; this reflects desensitisation of the PD for hypothalamic CRH output. We conclude that these factors are actively involved in the regulation of acute stress responses in the teleost fish.

Thermoneutral housing does not influence fat mass or glucose homeostasis in C57BL/6 mice

2018 ◽  
Vol 239 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Lewin Small ◽  
Henry Gong ◽  
Christian Yassmin ◽  
Gregory J Cooney ◽  
Amanda E Brandon
Keyword(s):  
Glucose Metabolism ◽  
Ambient Temperature ◽  
Fat Mass ◽  
Glucose Homeostasis ◽  
Dietary Intervention ◽  
Whole Body ◽  
Housing Temperature ◽  
Brown Adipose ◽  
Normal Chow ◽  
Obesogenic Diet

One major factor affecting physiology often overlooked when comparing data from animal models and humans is the effect of ambient temperature. The majority of rodent housing is maintained at ~22°C, the thermoneutral temperature for lightly clothed humans. However, mice have a much higher thermoneutral temperature of ~30°C, consequently data collected at 22°C in mice could be influenced by animals being exposed to a chronic cold stress. The aim of this study was to investigate the effect of housing temperature on glucose homeostasis and energy metabolism of mice fed normal chow or a high-fat, obesogenic diet (HFD). Male C57BL/6J(Arc) mice were housed at standard temperature (22°C) or at thermoneutrality (29°C) and fed either chow or a 60% HFD for 13 weeks. The HFD increased fat mass and produced glucose intolerance as expected but this was not exacerbated in mice housed at thermoneutrality. Changing the ambient temperature, however, did alter energy expenditure, food intake, lipid content and glucose metabolism in skeletal muscle, liver and brown adipose tissue. Collectively, these findings demonstrate that mice regulate energy balance at different housing temperatures to maintain whole-body glucose tolerance and adiposity irrespective of the diet. Despite this, metabolic differences in individual tissues were apparent. In conclusion, dietary intervention in mice has a greater impact on adiposity and glucose metabolism than housing temperature although temperature is still a significant factor in regulating metabolic parameters in individual tissues.

Consciousness

2018 ◽  
Author(s):  
Anil K. Seth
Keyword(s):  
Conscious Experience ◽  
Real Problem ◽  
Active Inference ◽  
Biological Mechanisms ◽  
Specific Content ◽  
Brain Responses ◽  
Biomimetic Approach ◽  
Multiple Levels ◽  
In Virtue Of ◽  
The Brain

Consciousness is perhaps the most familiar aspect of our existence, yet we still do not know its biological basis. This chapter outlines a biomimetic approach to consciousness science, identifying three principles linking properties of conscious experience to potential biological mechanisms. First, conscious experiences generate large quantities of information in virtue of being simultaneously integrated and differentiated. Second, the brain continuously generates predictions about the world and self, which account for the specific content of conscious scenes. Third, the conscious self depends on active inference of self-related signals at multiple levels. Research following these principles helps move from establishing correlations between brain responses and consciousness towards explanations which account for phenomenological properties—addressing what can be called the “real problem” of consciousness. The picture that emerges is one in which consciousness, mind, and life, are tightly bound together—with implications for any possible future “conscious machines.”

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