Neocortex saves energy by reducing coding precision during food scarcity.
Ontology highlight
ABSTRACT:
SUBMITTER: Padamsey Z
PROVIDER: S-EPMC8788933 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:To test wheather cavefish have higher lipogenesis capability than surface fish, we used liver sample from fasted and refed fish to do RNA-seq to compare their transcriptome responding to feeding in surface fish and Pachón cavefish. Moreover, we did the Pparγ ChIP-seq with liver from fed surface fish and Pachón cavefish. We amied to test whether Pparγ in Pachón cavefish have more biding sites and higher binding peaks than surface fish.
2022-02-10 | GSE173494 | GEO
Project description:Bats and birds must balance time and energy budgets during migration. Migrating bats face similar physiological challenges to birds, but nocturnality creates special challenges for bats, such as a conflict between travelling and refueling, which many birds avoid by feeding in daylight and flying at night. As endothermic animals, bats and birds alike must expend substantial amounts of energy to maintain high body temperatures. For migratory birds refueling at stopovers, remaining euthermic during inactive periods reduces the net refuelling rate, thereby prolonging stopover duration and delaying subsequent movement. We hypothesized that bats could mitigate similar ambient-temperature dependent costs by using a torpor-assisted migration strategy. We studied silver-haired bats Lasionycteris noctivagans during autumn migration using a combination of respirometry and temperature-sensitive radiotelemetry to estimate energy costs incurred under ambient temperature conditions, and the energy that bats saved by using torpor during daytime roosting periods. All bats, regardless of sex, age, or body condition used torpor at stopover and saved up to 91% of the energy they would have expended to remain euthermic. Furthermore, bats modulated use of torpor depending on ambient temperature. By adjusting the time spent torpid, bats achieved a rate of energy expenditure independent of the ambient temperature encountered at stopover. By lowering body temperature during inactive periods, fuel stores are spared, reducing the need for refuelling. Optimal migration models consider trade-offs between time and energy. Heterothermy provides a physiological strategy that allows bats to conserve energy without paying a time penalty as they migrate. Although uncommon, some avian lineages are known to use heterothermy, and current theoretical models of migration may not be appropriate for these groups. We propose that thermoregulatory strategies should be an important consideration of future migration studies of both bats and birds.
| S-EPMC4281203 | biostudies-literature
Project description:Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing revealed that food restriction modulated canonical, energy-regulating pathways including oxidative phosphorylation, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signalling, significantly in males but not in females V1. Moreover, we found that in contrast to males, food restriction in females non-significantly affected V1 ATP usage and visual coding precision (assessed by orientation selectivity). Decreased serum leptin is necessary for triggering energy-saving changes in male mouse V1 during food restriction. Consistent with this result, we found a significant decrease of serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to metabolic challenge.
2023-10-09 | GSE233435 | GEO
Project description:Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing in V1 revealed that in males, but not in females, food restriction significantly modulated canonical, energy-regulating pathways, including pathways associated waith AMP-activated protein kinase, peroxisome proliferator-activated receptor alpha, mammalian target of rapamycin, and oxidative phosphorylation. Moreover, we found that in contrast to males, food restriction in females did not significantly affect V1 ATP usage or visual coding precision (assessed by orientation selectivity). Decreased serum leptin is known to be necessary for triggering energy-saving changes in V1 during food restriction. Consistent with this, we found significantly decreased serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to food restriction.
| S-EPMC11230624 | biostudies-literature
Project description:Offspring are often produced in excess as insurance against stochastic events or unpredictable resources. This strategy may result in high early-life mortality, yet age-specific mortality before offspring independence and its associated costs have rarely been quantified. In this study, we modelled age-specific survival from hatching to fledging using 24 years of data on hatching order (HO), growth and age of mortality of more than 15 000 common tern (Sterna hirundo) chicks. We found that mortality peaked directly after hatching, after which it declined rapidly. Mortality hazard was best described with the Gompertz function, and was higher with later HO, mainly due to differences in baseline mortality hazard, rather than age-dependent mortality. Based on allometric mass-metabolism relationships and detailed growth curves of starving chicks, we estimated that the average metabolizable energy intake of non-fledged chicks was only 8.7% of the metabolizable energy intake of successful chicks during the nestling phase. Although 54% of hatchlings did not fledge, our estimates suggest them to have consumed only 9.3% of the total energy consumption of all hatched chicks in the population before fledging. We suggest that rapid mortality of excess offspring is part of an adaptive brood reduction strategy to the benefit of the parents.
| S-EPMC5326534 | biostudies-literature
Project description:Although there seems enough water available for our global food needs, there are large areas with growing water scarcity. Food security in these water scarce areas cannot be met through self-sufficiency. The only option is to become more dependent on food imports which is increasingly risky due to volatility in production and food prices. Before 2008, declining food prices and increasing global cereal production favoured the food import strategy. The 2008 world food crisis represented a shock to this strategy and renewed attention was paid to the self-sufficiency strategy. The aim of this paper is to compare the food security strategies of Egypt and Jordan, two water-stressed, increasingly populated, oil-poor countries, pre and post 2008, by means of a food-water analytical framework using FAOSTAT data. Findings show that Egypt and Jordan have many similarities in their food security situation as both are highly dependent on food imports (Egypt 50%, Jordan 95%), and both have a reduced capacity to absorb future price increases. As food imports are inevitable under the water scarce context of Egypt and Jordan, it is important to focus on how to cope with volatilities. Our analysis shows that Jordan has better absorbed the costs of rising food imports than Egypt and that Egypt is trapped by its high domestic cereal production. Having revealed the limited options available to water-scarce countries for food security, we discuss the potential of grain reserves to cope with future price hikes and production shocks.Supplementary informationThe online version contains supplementary material available at 10.1007/s12571-022-01310-y.
| S-EPMC9483414 | biostudies-literature
Project description:Scatter hoarders must allocate time to assess items for caching, and to carry and bury each cache. Such decisions should be driven by economic variables, such as the value of the individual food items, the scarcity of these items, competition for food items and risk of pilferage by conspecifics. The fox squirrel, an obligate scatter-hoarder, assesses cacheable food items using two overt movements, head flicks and paw manipulations. These behaviors allow an examination of squirrel decision processes when storing food for winter survival. We measured wild squirrels' time allocations and frequencies of assessment and investment behaviors during periods of food scarcity (summer) and abundance (fall), giving the squirrels a series of 15 items (alternating five hazelnuts and five peanuts). Assessment and investment per cache increased when resource value was higher (hazelnuts) or resources were scarcer (summer), but decreased as scarcity declined (end of sessions). This is the first study to show that assessment behaviors change in response to factors that indicate daily and seasonal resource abundance, and that these factors may interact in complex ways to affect food storing decisions. Food-storing tree squirrels may be a useful and important model species to understand the complex economic decisions made under natural conditions.
| S-EPMC3966826 | biostudies-literature
Project description:War is the cause of tremendous human suffering. To reduce such harm, governments have developed tools to alert civilians of imminent threats. Whether these systems are effective remains largely unknown. We study the introduction of an innovative smartphone application that notifies civilians of impending military operations developed in coordination with the Ukrainian government after the Russian invasion. We leverage quasi-experimental variation in the timing of more than 3,000 alerts to study civilian sheltering behavior, using high-frequency geolocation pings tied to 17 million mobile devices, 60% of the connected population in Ukraine. We find that, overall, civilians respond sharply to alerts, quickly seeking shelter. These rapid postalert changes in population movement attenuate over time, however, in a manner that cannot be explained by adaptive sheltering behavior or calibration to the signal quality of alerts. Responsiveness is weakest when civilians have been living under an extended state of emergency, consistent with the presence of an alert fatigue effect. Our results suggest that 35 to 45% of observed civilian casualties were avoided because of public responsiveness to the messaging system. Importantly, an additional 8 to 15% of civilian casualties observed during the later periods of the conflict could have been avoided with sustained public responsiveness to government alerts. We provide evidence that increasing civilians' risk salience through targeted government messaging can increase responsiveness, suggesting a potential policy lever for sustaining public engagement during prolonged episodes of conflict.
| S-EPMC10160968 | biostudies-literature
Project description:ImportanceDuring the COVID-19 pandemic, many US states issued or revised pandemic preparedness plans guiding allocation of critical care resources during crises. State plans vary in the factors used to triage patients and have faced criticism from advocacy groups due to the potential for discrimination.ObjectiveTo analyze the role of comorbidities and long-term prognosis in state triage procedures.Design, setting, and participantsThis cross-sectional study used data gathered from parallel internet searches for state-endorsed pandemic preparedness plans for the 50 US states, District of Columbia, and Puerto Rico (hereafter referred to as states), which were conducted between November 25, 2021, and June 16, 2023. Plans available on June 16, 2023, that provided step-by-step instructions for triaging critically ill patients were categorized for use of comorbidities and prognostication.Main outcomes and measuresPrevalence and contents of lists of comorbidities and their stated function in triage and instructions to predict duration of postdischarge survival.ResultsOverall, 32 state-promulgated pandemic preparedness plans included triage procedures specific enough to guide triage in clinical practice. Twenty of these (63%) included lists of comorbidities that excluded (11 of 20 [55%]) or deprioritized (8 of 20 [40%]) patients during triage; one state's list was formulated to resolve ties between patients with equal triage scores. Most states with triage procedures (21 of 32 [66%]) considered predicted survival beyond hospital discharge. These states proposed different prognostic time horizons; 15 of 21 (71%) were numeric (ranging from 6 months to 5 years after hospital discharge), with the remaining 6 (29%) using descriptive terms, such as long-term.Conclusions and relevanceIn this cross-sectional study of state-promulgated critical care triage policies, most plans restricted access to scarce critical care resources for patients with listed comorbidities and/or for patients with less-than-average expected postdischarge survival. This analysis raises concerns about access to care during a public health crisis for populations with high burdens of chronic illness, such as individuals with disabilities and minoritized racial and ethnic groups.
| S-EPMC10466166 | biostudies-literature
Project description:Both material resources (jobs, healthcare), and socio-psychological resources (social contact) decreased during the COVID-19 pandemic. We investigated whether individual differences in perceived material and socio-psychological scarcity experienced during the pandemic predicted preference for cooperation, measured using two Public Good Games (PGGs), where participants contributed money or time (i.e., hours indoors contributed to shorten the lockdown). Material scarcity had no relationship with cooperation. Increased perceived scarcity of socio-psychological wellbeing (e.g., connecting with family) predicted increased preference for cooperation, suggesting that missing social contact fosters prosociality, whilst perceived scarcity of freedom (e.g., limited movement) predicted decreased willingness to spend time indoors to shorten the lockdown. The importance of considering individual differences in scarcity perception to best promote norm compliance is discussed.
| S-EPMC9589443 | biostudies-literature