scholarly journals Downregulation of a satiety signal from peripheral fat bodies improves visual attention while reducing sleep need in Drosophila

2019 ◽  
Author(s):  
Deniz Ertekin ◽  
Leonie Kirszenblat ◽  
Richard Faville ◽  
Bruno van Swinderen
Keyword(s):  
Visual Attention ◽  
Cognitive Processes ◽  
Fat Body ◽  
Sleep Loss ◽  
Genetically Engineered ◽  
Night Time ◽  
Selective Visual Attention ◽  
Negative Side Effects ◽  
Fat Bodies ◽  
The Brain

AbstractSleep is vital for survival. Yet, under environmentally challenging conditions such as starvation, animals suppress their need for sleep. Interestingly, starvation-induced sleep loss does not evoke a subsequent sleep rebound. Little is known about how starvation-induced sleep deprivation differs from other types of sleep loss, or why some sleep functions become dispensable during starvation. Here we demonstrate that downregulation of unpaired-2 (upd2, the Drosophila ortholog of leptin), is sufficient to mimic a starved-like state in flies. We use this ‘genetically starved’ state to investigate the consequences of a starvation signal on visual attention and sleep in otherwise well-fed flies, thereby sidestepping the negative side-effects of undernourishment. We find that knockdown of upd2 in the fat body is sufficient to suppress sleep while also increasing selective visual attention and promoting night-time feeding. Further, we show that this peripheral signal is integrated in the fly brain via insulin-expressing cells. Together, these findings identify a role for peripheral tissue-to-brain interactions in the simultaneous regulation of sleep and attention, to potentially promote adaptive behaviors necessary for survival in hungry animals.Author SummarySleep is important for maintaining both physiological (e.g., metabolic, immunological, and developmental) and cognitive processes, such as selective attention. Under nutritionally impoverished conditions, animals suppress sleep and increase foraging to locate food. Yet it is currently unknown how an animal is able to maintain well-tuned cognitive processes, despite being sleep deprived. Here we investigate this question by studying flies that have been genetically engineered to lack a satiety signal, and find that signaling from fat bodies in the periphery to insulin-expressing cells in the brain simultaneously regulates sleep need and attention-like processes.

‘I saw a knock-out’: Fatness, (In)visibility, and Desire in Shallow Hal

Somatechnics ◽  
2012 ◽  
Vol 2 (1) ◽  
pp. 60-79 ◽  
Author(s):  
Jackie Wykes
Keyword(s):  
Female Body ◽  
Fat Body ◽  
Western Culture ◽  
Embodied Experience ◽  
Knock Out ◽  
Dominant Meaning ◽  
Starting Point ◽  
Female Bodies ◽  
Fat Bodies ◽  
Sexual Body

When the Farrelly brothers' movie Shallow Hal (2001) was released, one reviewer suggested that the film ‘might have been more honest if [it] had simply made Hal have a thing about fat women’ ( Kerr 2002 : 44). In this paper, I argue that Kerr hits the mark but misses the point. While the film's treatment of fat is undoubtedly problematic, I propose a ‘queer’ reading of the film, borrowing the idea of ‘double coding’ to show a text about desire for fat (female) bodies. I am not, however, seeking to position Shallow Hal as a fat-positive text; rather, I use it as a starting point to explore the legibility of the fat female body as a sexual body. In contemporary mainstream Western culture, fat is regarded as the antithesis of desire. This meaning is so deeply ingrained that representations of fat women as sexual are typically framed as a joke because desire for fat bodies is unimaginable; this is the logic by which Shallow Hal operates. The dominant meaning of fatness precludes recognition of the fat body as a sexual body. What is at issue is therefore not simply the lack of certain images, but a question of intelligibility: if the meaning of fat is antithetical to desire, how can the desire for – and of – fat bodies be intelligible as desire? This question goes beyond the realm of representation and into the embodied experience of fat sexuality.

Glycogen Phosphorylase in the Fat Body of Two Cockroach Species, Periplaneta americana and Nauphoeta cinerea: Isolation, Partial Characterization of Three Forms and Activation by Hypertrehalosaemic Hormones

1991 ◽  
Vol 46 (1-2) ◽  
pp. 149-162 ◽  
Author(s):  
Gerd Gäde
Keyword(s):  
Anion Exchange ◽  
Glycogen Phosphorylase ◽  
Periplaneta Americana ◽  
Fat Body ◽  
Phosphorylase Kinase ◽  
Phosphorylase Activity ◽  
Strong Inhibitor ◽  
Nauphoeta Cinerea ◽  
Crude Extracts ◽  
Fat Bodies

The presence of endogenous phosphorylase kinase and phosphorylase phosphatase in crude extracts of fat bodies from the cockroaches Nauphoeta cinerea and Periplaneta americana is demonstrated in vitro by activation/inactivation of glycogen phosphorylase under appropriate conditions. Fractionation of fat body extracts of both cockroach species on an anion-exchange medium results in the elution of three peaks with phosphorylase activity. According to their AMP dependency these activity peaks are designated as phosphorylase b (inactive without AMP), phosphorylase ab (active without AMP, but several stimulated with AMP) and phosphorylase a (active without AMP). It is shown chromatographically that incubating crude extracts of fat bodies from both cockroaches, under conditions where the phosphorylase kinase is active, results in all phosphorylase b being converted to the ab- or a-form , whereas under conditions where the phosphorylase phosphatase is active all phophorylase a is converted to the ab- or b-form . Endogenous phosphorylase kinase of N. cinerea crude fat body extract can convert vertebrate phosphorylase b into the a-form , and, conversely, vertebrate muscle p hosphorylase kinase and phosphorylase phosphatase, respectively, are able to convert partially purified N. cinerea phosphorylase aborb and the ab- und a-form , respectively. In resting cockroaches most of the phosphorylase activity resides in the b-form and only a small fraction (10% ) in the a-form , whereas between 26% (N . cinerea) and 35% (P. americana) occurs in the ab-form . Injection of endogenous hypertrehalosaemic peptides into N. cinerea (the decapeptide Bld-HrTH ) or P. americana (the two octapeptides Pea-CAH -I and II) causes interconversion of phosphorylase; after injection, mainly (60% ) phosphorylase a is present, while 25% and 15% exists in the ab- und b-form , respectively. Purification of the three phosphorylase forms from N. cinerea is achieved by anion-exchange chromatography on DEAE-Sephacel followed by affinity chromatography on AMP-Sepharose. The final specific activities are 2.1, 6.9 and 27.2 U /mg protein for the a-, ab- und b-form . The molecular mass of the active molecules on gel filtration is between 173,000 and 177,000, and SDS gel electrophoresis reveals a subunit mass of 87,100, suggesting a homodimeric structure for all three form s. Kinetic studies show hyperbolic saturation curves for the substrates glycogen and Pi respectively, with Kᴍ-values of 0.021, 0.019 and 0.073% for glycogen and 8.3, 6.3 and 17.9 mᴍ for Pi (a-, ab- and b-form ). Phosphorylase a exhibits a more or less hyperbolic response to AMP and needs 70 |iM A M P for m axim al stim ulation. The kinetics for the ab- and b-form s are sigm oidal and maximal activities are displayed at about 3 mᴍ (half-maximum activation as calculated from Hill plots are 55 and 280 μᴍ for the ab- und b-form , respectively). Caffeine is a strong inhibitor of the b-form , but has only a slight inhibiting effect (10 -20 % ) on the ab- and a-form in the presence of AMP.

scholarly journals Mobilizing the Sense of “Fat”: A Phenomenological Materialist Approach

Human Studies ◽  
2021 ◽  
Author(s):  
Jenny Slatman
Keyword(s):  
Lived Experiences ◽  
Fat Body ◽  
The Body ◽  
New Materialism ◽  
Writing Style ◽  
Conceptual Frame ◽  
Fat Bodies ◽  
The Way ◽  
Phenomenological Exploration

AbstractThis paper aims to mobilize the way we think and write about fat bodies while drawing on Jean-Luc Nancy’s philosophy of the body. I introduce Nancy’s approach to the body as an addition to contemporary new materialism. His philosophy, so I argue, offers a form of materialism that allows for a phenomenological exploration of the body. As such, it can help us to understand the lived experiences of fat embodiment. Additionally, Nancy’s idea of the body in terms of a “corpus”—a collection of pieces without a unity—together with his idea of corpus-writing—fragmentary writing, without head and tail—can help us to mobilize fixed meanings of fat. To apply Nancy’s conceptual frame to a concrete manifestation of fat embodiment, I provide a reading of Roxane Gay’s memoir Hunger (2017). In my analysis, I identify how the materiality of fat engenders the meaning of embodiment, and how it shapes how a fat body can and cannot be a body. Moreover, I propose that Gay’s writing style—hesitating and circling – involves an example of corpus-writing. The corpus of corpulence that Gay has created gives voice to the precariousness of a fat body's materialization.

scholarly journals Daytime micro-naps in a nocturnal migrant: an EEG analysis

2008 ◽  
Vol 5 (1) ◽  
pp. 77-80 ◽  
Author(s):  
T Fuchs ◽  
D Maury ◽  
F.R Moore ◽  
V.P Bingman
Keyword(s):  
Brain Activity ◽  
Sleep Loss ◽  
Eeg Analysis ◽  
Observable Effect ◽  
Brain Response ◽  
Night Time ◽  
Avian Migration ◽  
Unihemispheric Sleep ◽  
Daytime Behaviour ◽  
Behavioural Evidence

Many species of typically diurnal songbirds experience sleep loss during the migratory seasons owing to their nocturnal migrations. However, despite substantial loss of sleep, nocturnally migrating songbirds continue to function normally with no observable effect on their behaviour. It is unclear if and how avian migrants compensate for sleep loss. Recent behavioural evidence suggests that some species may compensate for lost night-time sleep with short, uni- and bilateral ‘micro-naps’ during the day. We provide electrophysiological evidence that short episodes of sleep-like daytime behaviour (approx. 12 s) are accompanied by sleep-like changes in brain activity in an avian migrant. Furthermore, we present evidence that part of this physiological brain response manifests itself as unihemispheric sleep, a state during which one brain hemisphere is asleep while the other hemisphere remains essentially awake. Episodes of daytime sleep may represent a potent adaptation to the challenges of avian migration and offer a plausible explanation for the resilience to sleep loss in nocturnal migrants.

Selective visual attention in patients with frontal lobelesions or Parkinsons disease

1999 ◽  
Vol 37 (5) ◽  
pp. 595-604 ◽  
Author(s):  
Sonia S Lee ◽  
Krista Wild ◽  
Caroline Hollnagel ◽  
Jordan Grafman
Keyword(s):  
Visual Attention ◽  
Parkinsons Disease ◽  
Selective Visual Attention

Central and Peripheral Clock Control of Circadian Feeding Rhythms

2021 ◽  
pp. 074873042110458
Author(s):  
Carson V. Fulgham ◽  
Austin P. Dreyer ◽  
Anita Nasseri ◽  
Asia N. Miller ◽  
Jacob Love ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Clock ◽  
Feeding Behavior ◽  
Molecular Clock ◽  
Fat Body ◽  
Molecular Clocks ◽  
Central Brain ◽  
Feeding Rhythms ◽  
Free Running ◽  
The Brain

Many behaviors exhibit ~24-h oscillations under control of an endogenous circadian timing system that tracks time of day via a molecular circadian clock. In the fruit fly, Drosophila melanogaster, most circadian research has focused on the generation of locomotor activity rhythms, but a fundamental question is how the circadian clock orchestrates multiple distinct behavioral outputs. Here, we have investigated the cells and circuits mediating circadian control of feeding behavior. Using an array of genetic tools, we show that, as is the case for locomotor activity rhythms, the presence of feeding rhythms requires molecular clock function in the ventrolateral clock neurons of the central brain. We further demonstrate that the speed of molecular clock oscillations in these neurons dictates the free-running period length of feeding rhythms. In contrast to the effects observed with central clock cell manipulations, we show that genetic abrogation of the molecular clock in the fat body, a peripheral metabolic tissue, is without effect on feeding behavior. Interestingly, we find that molecular clocks in the brain and fat body of control flies gradually grow out of phase with one another under free-running conditions, likely due to a long endogenous period of the fat body clock. Under these conditions, the period of feeding rhythms tracks with molecular oscillations in central brain clock cells, consistent with a primary role of the brain clock in dictating the timing of feeding behavior. Finally, despite a lack of effect of fat body selective manipulations, we find that flies with simultaneous disruption of molecular clocks in multiple peripheral tissues (but with intact central clocks) exhibit decreased feeding rhythm strength and reduced overall food intake. We conclude that both central and peripheral clocks contribute to the regulation of feeding rhythms, with a particularly dominant, pacemaker role for specific populations of central brain clock cells.

Priors and Prejudice: How prior knowledge shapes intergroup perception

2021 ◽  
Author(s):  
Hugh McGovern ◽  
Marte Otten
Keyword(s):  
Social Psychology ◽  
Prior Knowledge ◽  
Cognitive Processes ◽  
Social Neuroscience ◽  
Intergroup Bias ◽  
Predictive Processing ◽  
Future Research ◽  
Intergroup Perception ◽  
The Brain ◽  
Processing Framework

Bayesian processing has become a popular framework by which to understand cognitive processes. However, relatively little has been done to understand how Bayesian processing in the brain can be applied to understanding intergroup cognition. We assess how categorization and evaluation processes unfold based on priors about the ethnic outgroup being perceived. We then consider how the precision of prior knowledge about groups differentially influence perception depending on how the information about that group was learned affects the way in which it is recalled. Finally, we evaluate the mechanisms of how humans learn information about other ethnic groups and assess how the method of learning influences future intergroup perception. We suggest that a predictive processing framework for assessing prejudice could help accounting for seemingly disparate findings on intergroup bias from social neuroscience, social psychology, and evolutionary psychology. Such an integration has important implications for future research on prejudice at the interpersonal, intergroup, and societal levels.

Hymenolepis diminuta: metacestode-induced reduction in the synthesis of the yolk protein, vitellogenin, in the fat body of Tenebrio molitor

Parasitology ◽  
1996 ◽  
Vol 112 (4) ◽  
pp. 429-436 ◽  
Author(s):  
T. J. Webb ◽  
H. Hurd
Keyword(s):  
Post Infection ◽  
Fat Body ◽  
Potent Inhibitor ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Vitellogenin Synthesis ◽  
Specific Stage ◽  
Fat Bodies ◽  
Do So

SUMMARYVitellogenin synthesis by the fat body has been monitored using in vitro culture and immunoprecipitation. This system was found to be efficient for measuring vitellogenin production in both non-infected Tenebrio molitor and those infected with Hymenolepis diminuta. In fat bodies from infected beetles, vitellogenin production was decreased by up to 75% (day 24 post-infection) and, at all times investigated, vitellogenin synthesis was significantly below control levels (days 3–30 post-infection). Incubating fat bodies from control insects with isolated metacestodes indicated that this may be a direct effect by the parasite which is developmental stage-specific. Stage II, but not stage III–IV, nor heat-killed parasites could bring about this decrease in vitellogenin. In addition, these effects may be density dependent within the range of 2–20 parasites per fat body; only 2 metacestodes were necessary to cause a significant decrease. Since metacestodes do not take up vitellogenin, nor limit the amount of [14C] leucine available to the fat body for vitellogenin production, it is conceivable that the parasite produces a potent inhibitor of vitellogenin synthesis, or a molecule which induces cells within the fat body to do so.

Evolution de la masse corporelle et de la masse relative de quelques organes au cours du cycle annuel chez les mâles matures de Vipera aspis

1994 ◽  
Vol 15 (2) ◽  
pp. 123-133
Author(s):  
H. Saint Girons ◽  
R. Duguy
Keyword(s):  
Body Mass ◽  
Fat Body ◽  
Significant Decline ◽  
Sexual Cycle ◽  
Relative Mass ◽  
Rapid Decline ◽  
Slow Decline ◽  
Fat Bodies ◽  
Fat Body Mass ◽  
Vipera Aspis

AbstractThe relative mass of fat bodies of 103 adult male Vipera aspis from western France appeared to be correlated with fasting and feeding periods. There was a slow decline in mass during wintering and a rapid decline during the occurrence of spring mating; a minimum fat body mass was at the first molting time in May. This was the only time when there was a significant decline in the relative mass of the liver; vipers are noticeably emaciated during this period. Changes in relative kidney mass were correlated with the volume of the sexual segment of the kidneys, the minimum being in July. The relative mass of the testes was also linked with the sexual cycle; the minimum appeared to be in July and there was little variation between September and May.

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