scholarly journals ‘Central’ Actions of Corticosteroid Signaling Suggested by Constitutive Knockout of Corticosteroid Receptors in Small Fish

Nutrients ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 611 ◽  
Author(s):  
Tatsuya Sakamoto ◽  
Hirotaka Sakamoto

This review highlights recent studies of the functional implications of corticosteroids in some important behaviors of model fish, which are also relevant to human nutrition homeostasis. The primary actions of corticosteroids are mediated by glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), which are transcription factors. Zebrafish and medaka models of GR- and MR-knockout are the first constitutive corticosteroid receptor-knockout animals that are viable in adulthood. Similar receptor knockouts in mice are lethal. In this review, we describe the physiological and behavioral changes following disruption of the corticosteroid receptors in these models. The GR null model has peripheral changes in nutrition metabolism that do not occur in a mutant harboring a point mutation in the GR DNA-binding domain. This suggests that these are not “intrinsic” activities of GR. On the other hand, we propose that integration of visual responses and brain behavior by corticosteroid receptors is a possible “intrinsic”/principal function potentially conserved in vertebrates.

1991 ◽  
Vol 260 (2) ◽  
pp. E183-E188 ◽  
Author(s):  
J. Born ◽  
E. R. DeKloet ◽  
H. Wenz ◽  
W. Kern ◽  
H. L. Fehm

Cortisol modulates brain functions in humans. This principal endogenous glucocorticoid in humans decreases rapid-eye-movement (REM) sleep and increases slow-wave sleep (SWS). Because cortisol exerts its effect on brain functions via mineralocorticoid receptors (MR) and glucocorticoid receptors (GR), we were interested in which type of corticosteroid receptor mediates these steroid effects on sleep. Healthy men were tested in two double-blind experiments. In experiment I (n = 8), the subject's sleep was tested during four nights: 1) after pretreatment with dexamethasone (Dex, 4 mg/day) for 4 or 6 days and after additional infusion of placebo or cortisol (10 mg/h) during the experimental night, 2) after pretreatment with placebo for 4 or 6 days and after infusion of placebo or cortisol (10 mg/h) during the experimental night. In experiment II, subjects (n = 10) slept after intravenous administration of potassium canrenoate (200 mg, at 0800 and 1700 h before experimental nights) or placebo. Cortisol infusion moderately increased the percentage of SWS (P less than 0.05) and markedly decreased REM sleep (P less than 0.01); influence of cortisol on SWS did not depend on pretreatment with Dex. Dex reduced both SWS and REM sleep (P less than 0.05). Canrenoate markedly diminished SWS (P less than 0.01) but left REM sleep unaffected. The results suggest that corticosteroid-induced changes in SWS are mediated via MR-like central receptors in humans, whereas changes in REM sleep involve GR.


Endocrinology ◽  
2016 ◽  
Vol 157 (4) ◽  
pp. 1443-1456 ◽  
Author(s):  
Angela Katherine Odle ◽  
Melody Allensworth-James ◽  
Anessa Haney ◽  
Noor Akhter ◽  
Mohsin Syed ◽  
...  

Abstract Leptin regulates food intake and energy expenditure (EE) and is produced in adipocytes, the pituitary, and several other tissues. Animals that are leptin or leptin receptor deficient have major metabolic complications, including obesity. This study tests the hypothesis that the pituitary somatotrope may contribute a source of leptin that maintains some of these metabolic functions. We created 2 different tissue-specific leptin knockout animals: a Somatotrope-Lep-null model and an Adipocyte-Lep-null model. Metabolic analysis of both models, along with a global deletion model, was performed. The Somatotrope-Lep-null animals had fewer somatotropes, and females had a 76% decrease in serum prolactin. During the dark (feeding) phase, females had a 35% increase in ambulation coupled with a 4% increase in EE. Mutants showed no change in food intake or weight gain and EE was unchanged in males. During the light (sleep) phase, Somatotrope-Lep-null mutant males had lower EE and females continued to have higher EE. The respiratory quotients (RQs) of mutants and littermate controls were decreased in males and increased in females; all were within the range that indicates predominant carbohydrate burning. The massively obese Adipocyte-Lep-null animals, however, had significant increases in food intake, sleep, and increased EE, with decreased activity. Changes in RQ were sexually dimorphic, with female mutants having higher RQ and males having decreased RQ. We conclude that both adipocyte and somatotrope leptin contribute to the metabolic homeostasis of the mouse, and that extraadipocyte sources of leptin cannot overcome the major metabolic challenges seen in these animals.


2019 ◽  
Vol 42 ◽  
Author(s):  
Giulia Frezza ◽  
Pierluigi Zoccolotti

Abstract The convincing argument that Brette makes for the neural coding metaphor as imposing one view of brain behavior can be further explained through discourse analysis. Instead of a unified view, we argue, the coding metaphor's plasticity, versatility, and robustness throughout time explain its success and conventionalization to the point that its rhetoric became overlooked.


1977 ◽  
Vol 8 (4) ◽  
pp. 256-263
Author(s):  
Roberta Chapey ◽  
Geraldine Chapey

Occasionally, it is the responsibility of a supervisor to help a staff speech clinician resolve professional and or personal problems that interfere with the delivery of quality services. To deal with this situation, the supervisor must be equipped with the techniques and procedures for effective organizational communication. This article presents a case study in which a speech clinician demonstrated irresponsibility in various job areas. The supervisor’s philosophy and the procedures used in managing these problems are presented. The behavioral changes suggest that the supervisor’s interventive procedures were clinically significant and warrant further investigation.


ASHA Leader ◽  
2010 ◽  
Vol 15 (8) ◽  
pp. 18-21 ◽  
Author(s):  
Pélagie M. Beeson
Keyword(s):  

2006 ◽  
Vol 19 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Myriam Juda ◽  
Mirjam Münch ◽  
Anna Wirz-Justice ◽  
Martha Merrow ◽  
Till Roenneberg

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.


2010 ◽  
Vol 24 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Martin M. Monti ◽  
Adrian M. Owen

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.


2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.


2016 ◽  
Vol 21 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Paulo S. Boggio ◽  
Gabriel G. Rêgo ◽  
Lucas M. Marques ◽  
Thiago L. Costa

Abstract. Social neuroscience and psychology have made substantial advances in the last few decades. Nonetheless, the field has relied mostly on behavioral, imaging, and other correlational research methods. Here we argue that transcranial direct current stimulation (tDCS) is an effective and relevant technique to be used in this field of research, allowing for the establishment of more causal brain-behavior relationships than can be achieved with most of the techniques used in this field. We review relevant brain stimulation-aided research in the fields of social pain, social interaction, prejudice, and social decision-making, with a special focus on tDCS. Despite the fact that the use of tDCS in Social Neuroscience and Psychology studies is still in its early days, results are promising. As better understanding of the processes behind social cognition becomes increasingly necessary due to political, clinical, and even philosophical demands, the fact that tDCS is arguably rare in Social Neuroscience research is very noteworthy. This review aims at inspiring researchers to employ tDCS in the investigation of issues within Social Neuroscience. We present substantial evidence that tDCS is indeed an appropriate tool for this purpose.


Methodology ◽  
2005 ◽  
Vol 1 (2) ◽  
pp. 81-85 ◽  
Author(s):  
Stefan C. Schmukle ◽  
Jochen Hardt

Abstract. Incremental fit indices (IFIs) are regularly used when assessing the fit of structural equation models. IFIs are based on the comparison of the fit of a target model with that of a null model. For maximum-likelihood estimation, IFIs are usually computed by using the χ2 statistics of the maximum-likelihood fitting function (ML-χ2). However, LISREL recently changed the computation of IFIs. Since version 8.52, IFIs reported by LISREL are based on the χ2 statistics of the reweighted least squares fitting function (RLS-χ2). Although both functions lead to the same maximum-likelihood parameter estimates, the two χ2 statistics reach different values. Because these differences are especially large for null models, IFIs are affected in particular. Consequently, RLS-χ2 based IFIs in combination with conventional cut-off values explored for ML-χ2 based IFIs may lead to a wrong acceptance of models. We demonstrate this point by a confirmatory factor analysis in a sample of 2449 subjects.


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